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  • Methanation of CO2 over alkali-promoted Ru/TiO2 catalysts: I. Effect of alkali additives on catalytic activity and selectivity
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-20
    Athanasia Petala, Paraskevi Panagiotopoulou

    The effect of alkali promotion of TiO2 on the CO2 hydrogenation activity and selectivity has been investigated over 0.5%Ru/TiO2 and 5%Ru/TiO2 catalysts of different promoter type (Li, Na, K, Cs) and variable promoter loading (0.0–0.40 wt.%). The effect of alkali promotion was found to be more pronounced over catalysts of low Ru loading (or small Ru crystallites). In the case of 0.5%Ru/TiO2 catalysts, both catalytic activity and methane selectivity are strongly enhanced with the addition of small amounts (0.2 wt.%) of alkalis following the order of TiO2 (unpromoted) < Li ∼ K < Cs < Na. The intrinsic reaction rate exhibits a volcano-type dependence on the sodium content. Optimal results were obtained for 0.5%Ru/TiO2 catalyst containing 0.2 wt.% Na, the specific activity of which is about 3 times higher, compared to that of the unpromoted sample. In the case of 5%Ru/TiO2 catalysts, alkali addition does not practically affect catalytic activity and selectivity. Turnover frequency of 0.5%Ru/0.2%Na-TiO2 catalyst is higher than that measured over 5%Ru/TiO2, indicating that small amounts of alkalis can replace part of precious metals, reducing the cost and increasing the efficiency of the CO2 methanation process.

    更新日期:2017-11-20
  • Self-Assembled Synthesis of Defect-Engineered Graphitic Carbon Nitride Nanotubes for Efficient Conversion of Solar Energy
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-20
    Zhao Mo, Hui Xu, Zhigang Chen, Xiaojie She, Yanhua Song, Pengcheng Yan, Li Xu, Yucheng Lei, Shouqi Yuan, Huaming Li

    High-yield and uniform-size graphitic carbon nitride nanotubes (g-C3N4 nanotubes) with abundant nitrogen defects are synthesized for the first time, and just use melamine as a precursor, which embodies the concept of green, acid and alkali-free synthesis. And the morphology and performance are superior to the traditional molecular self-assembly (choose melamine and cyanuric acid as precursors), benefiting from melamine in situ turns into cyanuric acid and the release rate rather slowly. The g-C3N4 nanotubes show orderly morphology with length-diameter ratio of 30-70. The self-assembly of supramolecular intermediate is absolutely vital for the formation of g-C3N4 nanotubes with abundant nitrogen defects. A detailed process for the formation of defective g-C3N4 nanotubes is discussed. The g-C3N4 nanotubes exhibit excellent hydrogen evolution rate (118.5 μmol h−1), which is superior to the pure g-C3N4. The quantum efficiency of g-C3N4 nanotubes under irradiation at 420 nm is achieved to 6.8%, which is in the front rank of one dimension (1D) g-C3N4 structure, like g-C3N4 nanotubes, nanowires and nanorods. The improved photocatalytic performance benefits from the tubular structure and the nitrogen defects, which lead to the improved optical absorption, the more exposed active edges, the enhanced transfer and separation efficiency of the photogenerated electron-hole pairs, the higher surface area, fast and long-distance electron transport, the longer fluorescence lifetime and the nitrogen defects can act as the active sites. The g-C3N4 nanotubes also have broad applications in environmental treatement and photoelectrochemical detection of organic dyes. Additionally, the molecular self-assembled method can be a promising strategy for the shape-controlled synthesis of the other materials, like metal oxides and metal sulfides.

    更新日期:2017-11-20
  • Electrocatalytic Oxidation of Formaldehyde on Nanoporous Nickel Phosphate Modified Electrode
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-17
    A.H. Touny, Reham H. Tammam, M.M. Saleh

    Nanoporous nickel phosphate (nano-NiPh) is synthesized using a hydrothermal-based method from nickel phosphate precursors. It is applied for electrocatalytic oxidation of formaldehyde (FAL) in alkaline solution. The produced material is characterized using different techniques such as field emission scanning electron microscopy (FE-SEM), transmission electron micrograph (TEM) and X-ray diffraction (XRD) pattern. The nano-NiPh particles nearly reveal one-dimensional nanosize (200 × 800 nm) and demonstrate nanopores of ∼30 nm size. The chemical identity is found to be Ni3(PO4)2.8H2O. A nano-NiPh modified glassy carbon electrode (GC/nano-NiPh) is characterized by various techniques including cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The fabricated electrode demonstrates significant electrocatalytic activity towards the electrochemical oxidation of formaldehyde. The activity and stability of the electrode are discussed and some transport and kinetic parameters for FAL electrochemical oxidation have been determined.

    更新日期:2017-11-20
  • Influence of surface density on the CO2 photoreduction activity of a DC magnetron sputtered TiO2 catalyst
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    F. Fresno, P. Reñones, E. Alfonso, C. Guillén, J.F. Trigo, J. Herrero, L. Collado, V.A. de la Peña O’Shea

    Advancing in the photocatalyst scale-up is crucial for the development of highly efficient solar fuels production at industrial scale. Here, we report DC-magnetron sputtering as a suitable technique to produce photocatalytic TiO2 coatings for CO2 reduction with a view on process scalability. The crystallinity of the obtained TiO2 coatings varies with surface density, with amorphous or quasi-amorphous coatings obtained with very low densities, while UV light absorption coefficients show the opposite trend, which has been related to the proportionally higher abuundace of surface defects and grain boundaries associated to the small crystal size and/or amorphicity of the lightest coatings. The as-prepared samples lead to the reduction of CO2 as demonstrated by 13C isotope tracing. An optimum catalyst area density of 1 g/m2 (by geometric area) is obtained in terms of CO2 photoreduction production, which is ascribed to a compromise situation between crystallinity and absorption coefficient. Selectivity to the different reaction products also varies with the coating characteristics, with amorphous or quasi-amorphous light coatings favouring methanol formation, in contrast with the preferred CO evolution in heavier, crystalline ones. Raman spectroscopy reveals the formation of peroxo and peroxocarbonate species on the photocatalyst surface as oxidation products during the CO2 reduction, the accummulation of which is proposed to be related to the observed catalyst deactivation.

    更新日期:2017-11-20
  • Robust visible/near-infrared light driven hydrogen generation over Z-scheme conjugated polymer/CdS hybrid
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Xiaohu Zhang, Jie Xiao, Min Hou, Yonggang Xiang, Hao Chen

    Direct Z-scheme organic/inorganic semiconductor hybrid is seldom reported for photocatalytic H2 production from water splitting. Reported herein is a new type of organic/inorganic hybrid fabricated with modified conjugated polybenzothiadiazole (B-BT-1,4-E, noted as BE) flake and CdS nanorod. The internal Z-scheme electron transfer mechanism is evidenced by detecting the loading position of Pt through a in-situ photodeposition technique. It is found that the Z-scheme BE-CdS hybrid possesses broad visible/near-infrared (vis/NIR) light absorption region (400–700 nm) and rapid photogenerated e−/h+ separation rate. Photocatalytic performances reveal that the H2 production rate of optimal cocatalyst-free BE-CdS hybrid is 8.3 and 23.3 times higher than that of CdS and BE respectively, and a high apparent quantum yield (AQY) of 7.5% at 420 nm is obtained over the hybrid catalyst. This work opens new opportunities for exploiting highly efficient solar water splitting performances.

    更新日期:2017-11-20
  • Comparison of importance between separation efficiency and valence band position: The case of heterostructured Bi3O4Br/α-Bi2O3 photocatalysts
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Jian-guo Guo, Ying Liu, Ying-juan Hao, Yi-lei Li, Xiao-jing Wang, Rui-hong Liu, Fa-tang Li

    Heterostructured Bi3O4Br/α-Bi2O3 nanocomposites are prepared via in situ one-step self-combustion of ionic liquids. Tetrabutylammonium bromide (TBAB) is employed to be fuel, complexing agent for ionic liquids, as well as the reactant supplying Br for the objective material. The ratio of Bi3O4Br/α-Bi2O3 can be easily adjusted by controlling the amount of TBAB. The heterojunctions show higher photocatalytic ability towards both azo dye methyl orange (MO) and colorless pollutant phenol. The electron spin resonance (ESR) test and p-nitro blue tetrazolium chloride (NBT) degradation result indicate that generation amounts of superoxide anion radicals ( radical dot O2−) over heterojunctions are less than that over pure Bi3O4Br. Photoelectrochemical measurements show that separation efficiencies of photo-generated electrons and holes are decreased after the combination of Bi3O4Br and α-Bi2O3. Work function test and scavenger experiments display that holes play key role for pollutant degradation and the position of holes on α-Bi2O3 is lowered via hybridization. Thus, the enhanced photocatalytic activity over composites can be attributed to the position decline of α-Bi2O3 valence band, thus improving the reactivity of holes in direct oxidation of pollutants. In this case, valence band position is confirmed to be more important than separation efficiency of charge carriers in affecting photocatalytic performance.

    更新日期:2017-11-20
  • Constructing magnetic catalysts with in-suit solid-liquid interfacial photo-Fenton-like reaction over Ag3PO4@NiFe2O4 composites
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Shuquan Huanga, Yuanguo Xua, Ting Zhoua, Meng Xiea, Yun Maa, Qingqing Liua, Liquan Jinga, Hui Xua, Huaming Lia

    A high-performance photocatalyst should be superior not only in light absorption and charge transfer but also surface catalytic reaction. Here we report a green and simple strategy for evenly decorating Ag3PO4 particles using magnetic NiFe2O4 nanoparticles (NPs). The NiFe2O4 NPs could not only act as a magnetic support material for recycling the photocatalysts, but also in suit catalytically decompose the H2O2 produced on the surface of Ag3PO4 into O2 radical dot − and radical dot OH radicals via a photo-Fenton process. The catalytic decomposition of H2O2 could produce strong oxidative capacity O2 radical dot − and radical dot OH radicals for the organic pollutants degradation and reduce host semiconductor holes (h+(Ag3PO4)) consumption by the produced H2O2. Thus, the photocatalytic activities of Ag3PO4@NiFe2O4 composites were greatly enhanced. Taking the photocatalytic degradation of Methyl orange (MO), hardly decomposed colorless phenol compounds bisphenol A (BPA) and killing Escherichia coli (E. coli) as mode photocatalytic reactions, this system exhibited superior photocatalytic performances than that of pristine Ag3PO4. Electron spin resonance (ESR) spectroscopy and sacrificial-reagent incorporated photocatalytic characterizations indicated that the in suit eliminating/active decomposition of H2O2 produced by Ag3PO4 was the main reason for the enhanced photocatalytic activities.

    更新日期:2017-11-20
  • Formation of N2O Greenhouse Gas during SCR of NO with NH3 by Supported Vanadium Oxide Catalysts
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Minghui Zhu, Jun-Kun Lai, Israel E. Wachs

    Selective catalytic reduction of NO by NH3 over supported vanadium oxide catalysts has been studied for decades, but the studies mostly concentrated on the dominant N2 product with much less attention paid to the formation of the undesired N2O product. In the present study, fundamental aspects of the N2O formation reaction were elucidated by a series of temperature-programmed surface reaction studies with isotopic labeled reactants. The surface vanadium oxide species on the TiO2 support are active sites for the N2O formation reaction, while tungsten species mainly function as promoters. Oxygen from NO, gaseous O2 and catalyst oxygen all function as oxygen sources for formation of N2O (∼50%, ∼30% and ∼20%, respectively). The rate-determining-step for N2O formation involves breaking of the ammonia N single bond H bond. These new molecular level insights have the potential to guide the rational design of improved SCR catalysts for diesel engines with reduced N2O produced.

    更新日期:2017-11-20
  • Novel β-NiS film modified CdS nanoflowers heterostructure nanocomposite: extraordinarily highly efficient photocatalysts for hydrogen evolution
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Yu Zhang, Zhijian Peng, Shundong Guan, Xiuli Fu

    The compositing of semiconductor based photocatalysts with cocatalysts is a well-known, effective strategy to acquire high hydrogen evolution efficiency, for which their morphology and composition are the concerns of most literatures. However, the contact between them, which has been always difficult to improve, is also a key factor. Here a novel β-NiS film modified CdS nanoflowers (NiS/CdS NFs) heterostructure nanocomposite (HSNC) was successfully synthesized through a simple one-pot hydrothermal method. The obtained NiS/CdS NFs HSNC has well-constructed integrated structure of strong adhesion between the semiconducting CdS NFs and the cocatalyst NiS thin films, displaying good transfer ability to photogenerated electrons and high adsorption to visible light together. Resultantly, the obtained composite presents extraordinarily highly efficient photocatalytic hydrogen evolution, and high chemical and structural stability in aqueous solution containing 20 vol.% lactic acid under visible light. The highest rate for hydrogen production reached a recorded value of about 30.1 mmol h−1 g−1 at 25 °C among all CdS-NiS composite catalysts, and the highest apparent quantum efficiency was approximately 43% at 420 nm. The growth and photocatalysis mechanisms for the NiS/CdS NFs were proposed.

    更新日期:2017-11-17
  • Structural and Electronic Properties of Oxygen Defective and Se-Doped p-Type BiVO4(001) Thin Film for the Applications of Photocatalysis
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Habib Ullah, Asif A. Tahir, Tapas K. Mallick

    Monoclinic BiVO4 is being used as a photocatalyst due to its stability, cost-effectiveness, ease of synthesis, and narrow band gap. Although, the valence band maximum, VBM (∼ −6.80 eV vs vacuum) of BiVO4 is well below the redox potential of water but having less positive conduction band minimum, CBM (-4.56 eV vs vacuum), responsible for its low efficiency. We have carried out a comprehensive periodic density functional theory (DFT) simulations for the pristine, Oxygen defective (Ov) and Se doped BiVO4, to engineer not only its CB edge position but the overall photocatalytic and charge carrier properties. Our theoretical method has nicely reproduced the experimental data of pristine BiVO4, which encouraged us to elaborate further its Ov and Se-doped characteristics. It is found that both the Ov (1% Oxygen vacancy) and Se-doped BiVO4 (1 to 2% Se) have ideal band edges, band gaps, and small effective masses of electrons and holes, responsible for high photocatalytic activities. Moreover, Se-doped BiVO4 behave as p-type semiconductor. Finally, the photocatalytic water-splitting behaviour of the selected surfaces were counterchecked with water interaction, where the strong water adsorption energy of about ∼-38 to −50 kcal/mol, confirms and predicts their higher efficiencies compared to that of parent BiVO4.

    更新日期:2017-11-17
  • Alkali-assisted fabrication of holey carbon nitride nanosheet with tunable conjugated system for efficient visible-light-driven water splitting
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Ting Song, Piyong Zhang, Tingting Wang, Atif Ali, Heping Zeng

    Graphitic carbon nitride (CN) nanosheets have aroused a great deal of interest due to their capability to utilize visible light to split water into its constituent molecules of hydrogen and oxygen (H2 and O2). However, the photocatalytic capacity of conventional bulk g-C3N4, with its large π-π conjugated electronic system, is still constrained by the π-π stacking interaction and small number of active sites. Hence, an uncomplicated post-processing method to construct a different π-π conjugated electronic system of holey CN nanosheets using alkali etching of bulk CN (CN (B)) at 300 °C for 1 h has been developed. Among such compounds, the optimal alkali treatment bulk CN (CN 3(2)) exhibits a suitable conjugated system and copious in-plane holes, and it retains the ability to absorb sunlight during alkali depolymerization. Compared to CN (B), the resultant CN 3(2) has a distensible bandgap of 2.66 eV associated with a much larger specific surface area of 265.2 m2 g−1. However, excessive alkali treatment significantly decrease the visible light absorbance and the photocatalytic properties of the CN nanosheet, which demonstrated that a suitable π-π conjugated electronic system is very important in allowing the process to proceed. As such, the photocatalytic H2 and O2 production rate of CN 3(2) was nearly 24.6 times that of CN (B) with the addition of carbon quantum dots (CQDs) and Pt.

    更新日期:2017-11-17
  • High efficiency water splitting photoanodes composed of nano-structured anatase-rutile TiO2 heterojunctions by pulsed-pressure MOCVD
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-16
    Aleksandra J. Gardecka, Catherine Bishop, Darryl Lee, Sacha Corby, Ivan P. Parkin, Andreas Kafizas, Susan Krumdieck

    In this article, thin solid films are processed via pulsed-pressure metal organic chemical vapour deposition (PP-MOCVD) on FTO substrates over a range of processing times to produce a range of thicknesses and microstructures. The films are highly nanostructured anatase-rutile TiO2 composite films with unique single crystal dendrites. After annealing, carbon was removed, and materials showed improved water splitting activity; with IPCEs above 80% in the UV, photocurrents of ∼1.2 mA.cm−2 at 1.23 VRHE at 1 sun irradiance and an extension of photoactivity into the visible range. The annealed material exhibits minimal recombination losses and IPCEs amongst the highest reported in the literature; attributed to the formation of a high surface area nanostructured material and synergetic interactions between the anatase and rutile phases.

    更新日期:2017-11-17
  • A novel route combined precursor-hydrothermal pretreatment with microwave heating for preparing holey g-C3N4 nanosheets with high crystalline quality and extended visible light absorption
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Qiong Liu, Xueli Wang, Qian Yang, Zhengguo Zhang, Xiaoming Fang

    The photocatalytic water splitting for hydrogen fuel by utilizing solar energy is considered a useful route to settle the energy crisis, but a bottleneck is occurred in developing a highly efficient photocatalysts. Herein, a facile method is applied to fabricate the holey carbon nitride (HCN) nanosheets with high crystallization network and extended optical absorption region by using the hydrothermal and microwave processes. The hydrothermal treatment of dicyandiamide will enable it to transform into the melamine-cyanaurate complex which would then form the ultrathin CN nanosheets with the abundant porous structure. And then the microwave-assisted thermolysis process helps the generation of g-C3N4 which retains the highly crystalline and the enhanced optical absorption region. Eventually, the highly crystalline network comes with the narrowed band gap and the higher specific surface area encounter in optimized g-C3N4 leading it exhibits a relatively high photocatalytic performance than pristine bulk carbon nitride which the hydrogen evolution rate of it reaching 81.6 μmol/h.

    更新日期:2017-11-17
  • Cobalt Manganese Spinel as an Effective Cocatalyst for Photocatalytic Water Oxidation
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Linzhu zhang, Can Yang, Zailai Xie, Xinchen Wang

    Efficient co-catalysts are crucial for photocatalytic water oxidation towards conversion of solar energy into chemical energy. Herein, we develop a sustainable and effective water oxidation system using graphitic carbon nitride (g-C3N4) and cubic cobalt manganese spinel (c-CoMn2O4) as light transducer and water oxidation co-catalyst, respectively. The surface modified g-C3N4 with c-CoMn2O4 not only accelerates the interface transfer rate of charge carriers but also reduces the excessive energy barrier for O-O formation, leading to an enhanced photocatalytic activity of water oxidation. Benefiting from the well surface engineering of g-C3N4, the g-C3N4-CoMn2O4 (CN-CM) composites exhibit an enhanced performance of photocatalytic water oxidation. The oxygen evolution rate (OER) of CN-CM is 4 times higher than that of pristine g-C3N4. It is a highly active in oxidation of water, with an apparent quantum yield (AQY) of ca. 1% at 380 nm with AgNO3 as sacrificial agent. This improvement is mainly due to the mixed-valence Co and Mn cations contained in c-CoMn2O4 spinel.

    更新日期:2017-11-17
  • Isothermic adsorption of morin onto the reducible mesoporous manganese oxide materials surface
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Ali K. Ilunga, Itumeleng R. Legodi, Simbongile Gumbi, Reinout Meijboom

    A series of mesoporous manganese oxide materials were synthesized following the inverse micelle sol-gel method and categorized by the heat treatment. The tunable features and crystallinity of the mesoporous materials were analyzed by BET and XRD analyses. The HR-TEM and TRP analyses were conducted to analyze the meso-ordered structure and reducibility of the mesoporous manganese oxide materials. The catalytic activity of the mesoporous materials was investigated in aerobic oxidation of morin as a model reaction. The experimental data were interpreted according to the Mars-van Krevelen and Langmuir-Hinshelwood approach. The heat treatment influenced the crystallite size and the activity of the mesoporous manganese oxide materials. The activity of the lattice oxygen was a critical factor in the aerobic process. MnO2–350 °C exhibited the largest lattice oxygen activity ((64.3 ± 5.6) × kJ mol−1 m−2).

    更新日期:2017-11-17
  • Homogeneous Introduction of CeOy into MnOx-based Catalyst for Oxidation of Aromatic VOCs
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-15
    Jin Chen, Xi Chen, Xi Chen, Wenjian Xu, Zhen Xu, Hongpeng Jia, Jing Chen

    3MnOx-1CeOy (3Mn1Ce), a binary oxide with stoichiometric ratio of Mn/Ce = 3, is synthesized via hydrolysis driving redox. Compared to MnO2, CeO2, Cop-3Mn1Ce and Mixed-3Mn1Ce, the 3Mn1Ce catalyst exhibits better catalytic activity for toluene oxidation, which could be ascribed to higher concentration of active lattice oxygen, and better low-temperature reducibility, as well as homogeneous dispersion. In the test of substrate applicability, 3Mn1Ce displays good performances in the removal of benzene, o-xylene and chlorobenzene at moderate temperature. The application of high WHSV of 240000 mL/(g h) confirms the 3Mn1Ce catalyst still remains high efficiency to diminish toluene, giving the temperature at 280 °C for complete mineralization. A set of experiments under simulated realistic exhaust conditions demonstrate that 3Mn1Ce is a robust catalyst with high activity to oxidize mixed aromatic VOCs (BTX and chlorobenzene), satisfied endurability to high humidity (above 10 − 20 vol.% water) and good tolerance to severe change of reaction temperature. With characterization of XRD and TPR, the high performance is related to the homogeneous introduction of Ce resulting in higher structural stability and reversible reducibility. Moreover, the inner principle for oxidation of VOCs is revealed by comprehension of kinetic study.

    更新日期:2017-11-17
  • Enhanced Visible-Light Photocatalytic Activity of Bi2MoO6 Nanoplates with Heterogeneous Bi2MoO6-x@Bi2MoO6 Core-Shell Structure
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-13
    Jianhui Guo, Lei Shi, Jiyin Zhao, Yang Wang, Kaibin Tang, Wanqun Zhang, Changzheng Xie, Xueyou Yuan

    A series of Bi2MoO6 (BMO) nanoplates with a heterogeneous Bi2MoO6-x@Bi2MoO6 core/shell structure were successfully obtained by reduction with CaH2 at 140 °C and subsequent reoxidation in air under low temperatures (≤250 °C). It is found that the oxygen vacancies mainly exist in the core, while the shell is formed by surface disorder layer with few oxygen vacancies, which is almost stoichiometric. The controllable growth of the surface disorder layer can be realized by the reduction and/or reoxidation temperatures. The reoxidized BMO with the surface disorder layer exhibits about five times higher visible-light photocatalytic activity toward phenol degradation and an order of magnitude higher activity toward methylene blue (MB) degradation than those of the unmodified sample. The visible-light absorption is mainly dominated by the oxygen vacancies through the modulation of the band gap structure, which promote the solar light utilization and photogenerated charge carriers. Density functional theory calculation shows that BMO is a direct band gap semiconductor. It is suggested that the surface disorder layer could suppress the direct recombination of photogenerated carriers and improve surface reactivity, and results in the enhancement of the photocatalytic activivity. In addition, the existence of the stoichiometric surface disorder can promote the catalyst stability. It is demonstrated that the reduction- reoxidation method applied here is simple, easily control, and beneficial for the design and realization of heterogeneous core-shell nanostructured photocatalysts to improve visible and infrared optical absorption by engineering the surface disorder and the oxygen vacancies inside core of Bi2MoO6 nanoplates and the related nanostructured photocatalysts.

    更新日期:2017-11-14
  • UV-visible-infrared light-driven photothermocatalytic abatement of CO on Cu doped ramsdellite MnO2 nanosheets enhanced by a photoactivation effect
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-11
    Yi Yang, Yuanzhi Li, Min Zeng, Mingyang Mao, Lan Lan, Huihui Liu, Jian Chen, Xiujian Zhao

    The Cu doped ramsdellite MnO2 nanosheet samples with different Cu/Mn molar ratio were prepared by a facile hydrothermal redox reaction among Cu(NO3)2, Mn(NO3)2, and KMnO4 at 60 °C. They were characterized by ICP-OES, XRD, TEM, SEM, N2 adsorption, XPS, UV-vis-IR absorption, etc. The Cu doped ramsdellite MnO2 nanosheet samples demonstrate highly efficient photothermocatalytic activity and very good catalytic stability for the catalytic purification of CO as one of poisonous air pollutants under the full solar spectrum infrared irradiation. Compared to the pure ramsdellite MnO2 nanosheet sample and TiO2(P25), the photothermocatalytic activity of the optimum Cu doped ramsdellite MnO2 nanosheet sample under the full solar spectrum irradiation is enhanced by 2.3, 281.7 times, respectively. The Cu doped ramsdellite MnO2 nanosheet sample also demonstrates highly efficient catalytic activity even under the λ > 830 nm infrared irradiation. The highly efficient catalytic activity of the Cu doped ramsdellite MnO2 nanosheet sample derives from efficient solar-light-driven thermocatalysis because of its strong absorption across the entire full solar spectrum and high thermocatalytic activity. The Cu doping considerably enhances the lattice oxygen activity of ramsdellite MnO2, thus promoting its thermocatalytic activity. A novel photoactivation, completely unlike the well-known photocatalysis on photocatalytic semiconductors such as TiO2, is discovered to further enhance the solar-light-driven thermocatalytic activity. We combine the experimental evidence of CO-TPR and DFT calculation to reveal the origin of the novel photoactivation: the irradiation considerably enhances the lattice oxygen activity of the Cu doped ramsdellite MnO2 nanosheets, thus accelerating their solar-light-driven thermocatalytic activity.

    更新日期:2017-11-13
  • Black NiO-TiO2 nanorods for solar photocatalysis: Recognition of electronic structure and reaction mechanism
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-11
    Jie Liu, Ying Li, Jun Ke, Shaobin Wang, Lidong Wang, Huining Xiao

    This work provides an engineering guide to construct active sites on TiO2 nanorods (NRs) by coupling p-type black NiO nanoclusters (Eg = 1.42 eV) with rich crystal defects and match-up band structure for excellent solar photocatalysis. Photo-oxidation of toluene was used as a model reaction to evaluate the photocatalytic performance of black NiO/TiO2 hybrids under simulated solar light irradiation from a 300 W Xe-lamp. The black NiO/TiO2 hybrids Exhibit 80% of photodegradation conversion and 56% of mineralization efficiency, which are 7.9 and 4.5 times higher than those of TiO2 NRs. Detailed characterizations reveal that highly dispersed NiO and p-n heterojunction effectively facilitate light-harvesting, separation and transfer of photo-generated charge carries, and significantly inhibit the recombination of electrons and holes. Furthermore, the realignment of band structure and the p-n heterojunctions in NiO/TiO2 result in the production of &903;O2− and h+ with a longer lifetime, which could efficiently attack the aromatic ring of toluene. The efficient adsorption of toluene by H-bonding formation also facilitates the photo-oxidation of toluene on NiO/TiO2.

    更新日期:2017-11-13
  • Direct unassisted hydrogen peroxide generation from oxygen and water on plasmonic Ag-graphene-Cu nanosandwitch
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-11
    Yaxing Liu, Fuyi Chen, Qiao Wang, Junpeng Wang, Jiali Wang

    A nanosandwich made from Ag nanoparticles (Ag NPs) arrays, the two-dimension single-layer graphene (SG) and metallic Cu contact was constructed for the hydrogen peroxide (H2O2) generation utilizing solar energy without an external bias. The shifting of binding energy towards lower energy in Ag core-level electronic spectrum is an evidence of strong coupling between Ag and graphene, which can efficiently transfer hot-holes from Ag to Cu by a built-in electric field so that the hot-electrons on Ag NPs are directly utilized to initiate the H2O2 generation. This Ag-graphene-Cu nanosandwitch can provide a stable photocurrent of −15.8 μA cm−2, a stable photovoltaic voltage of 17.5 mV cm−2, and a H2O2 yield of 229.33 μM after 6 hours. To understand the mechanism of oxygen reduction reaction (ORR) in Ag-graphene-Cu systems, the electron transfer number for photocatalytic ORR and the surface facet of Ag NPs were studied. The Ag NPs in Ag-graphene-Cu systems with the deposition time of 180 s clearly shows that an amount of 〈200〉 facets are distributed on Ag nanoparticle surface, which can catalyze ORR by 2-electron pathway to generate H2O2 efficiently. This novel Ag-graphene-Cu nanosandwitch offers a new transfer path for hot-electrons and potentially provides a new concept for driving efficient solar energy to chemical energy.

    更新日期:2017-11-13
  • Plasmonic molybdenum oxide nanosheets supported silver nanocubes for enhanced near-infrared antibacterial activity: synergism of photothermal effect, silver release and photocatalytic reactions
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-11
    Qiaoqiao Yin, Linxiang Tan, Qingqing Lang, Xiaoxia Ke, Lijie Bai, Kaiyan Guo, Ru Qiao, Song Bai

    Plasmonic MoO3-x nanosheets supported Ag nanocubes were designed as high-efficient Near-infrared (NIR) light driven antibacterial agent. The as-designed MoO3-x-Ag not only significantly reduces the cost and toxicity of Ag, but also greatly enhances the antibacterial activity towards E. coli and S. aureus in comparison with bare MoO3-x and Ag upon NIR laser irradiation. Three effects are believed to contribute to this enhancement: (1) the plasmonic MoO3-x-Ag exhibits excellent NIR light absorption and photothermal conversion abilities, which help to kill bacteria; (2) NIR light induced heat in MoO3-x also diffuses to Ag nanocubes and triggers the release of more Ag+, leading to bacterial cell death; (3) under NIR light irradiation, hot electrons and holes are generated and separated through MoO3-x-Ag interface, which produces reactive species for the oxidation of out membrane of bacteria. The synergism of NIR light driven photothermal effect, silver release and photocatalytic reaction makes the designed plasmonic MoO3-x-Ag a promising antibacterial agent for cleaning the microbial contaminated water environment.

    更新日期:2017-11-13
  • Antimicrobial Activity of Photocatalysts: Fundamentals, Mechanisms, Kinetics and Recent Advances
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-11
    Priyanka Ganguly, Ciara Byrne, Ailish Breen, Suresh C. Pillai

    Photocatalysis has recently been emerged as an effective green solution for antimicrobial disinfection applications. Photocatalytic disinfection has been observed to be constructive in deactivation of an extensive variety of organisms. Numerous gram positive and gram negative bacterial strains such as Escherichia coli, Staphylococcus aureus, Streptococcus pneumonia etc. have been studied. Similarly, fungal strains such as Aspergillus niger, Fusarium graminearum, Algal (Tetraselmis suecica, Amphidinium carterae etc.) and viral strains have also been examined in these last decades. The present review sketches the photocatalytic mechanism and provides a brief account of several model organisms used for the disinfection studies. It presents an overview of the major kinetic models such as the Chick’s model, Chick-Watson model, delayed Chick- Watson model and Hom’s with modified Hom’s model. Furthermore, it summarises the importance of operational parameters on the inactivation kinetics and discusses the recent advances of the disinfection results by novel composites and progress in structural or morphological improvements in conventional catalyst. The current review presents a brief overview of the state of the art commercial products utilising photocatalytic antibacterial property. Finally, it details the major international testing standards (ISO, JIS, CEN and ASTM) for photocatalytic antimicrobial applications

    更新日期:2017-11-13
  • First-principle calculation study of tri-s-triazine-based g-C3N4: a review
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-11
    Bicheng Zhu, Liuyang Zhang, Bei Cheng, Jiaguo Yu

    Graphitic carbon nitride (g-C3N4) is an attractive photocatalyst which has appealing visible light absorption, outstanding layered porous structure, high stability and nontoxicity. Many experimental methods have been developed to modify the pristine g-C3N4 and enhanced photocatalytic activities have been witnessed. First-principle calculation based on density functional theory is an effective approach to investigate the structural, electronic, optical and thermodynamic properties of molecules and crystals, which provides important information to elucidate the improved photocatalytic activity of modified g-C3N4 at atomic or unit-cell levels, or even further, to predict the property and photocatalytic activity of experimentally un-synthesized g-C3N4-based photocatalysts. This review is dedicated to this important material, i.e. tri-s-triazine-based g-C3N4 and summarized a panorama of the major advances in the first-principle investigation. The existing challenges and future directions at the forefront of this emerging research hotpot have also been discussed.

    更新日期:2017-11-13
  • Understanding the “Seesaw Effect” of interlayered K+ with different structure in manganese oxides for the enhanced formaldehyde oxidation
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-10
    Jinlong Wang, Jun Li, Pengyi Zhang, Gaoke Zhang

    Although the potassium-promoted catalysts exhibit improved catalytic activities, the role of potassium with different structural sites still needs to be studied by more experiments and theory calculation. Herein, potassium (K+) formed via different binding sites (isolated and localized) over layered MnO2 was investigated. The isolated K+ dissociated between layers via weak chemical bond while localized K+ coordinated with oxygen atoms at vacancy site. K+ with localized type (L-MnO2) exhibited the higher activity and the lower Ea (45.2 kJ/mol), compared with isolated one (58.1 kJ/mol) under 200 ppm HCHO, 120,000 mL/g h GHSV and ∼45% relative humidity. Evidenced by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), hydrogen temperature programmed reduction (H2-TPR) and density functional theory (DFT) simulation, the isolated K+ in interlayer are energetically favourable for dissociation of O2 as well as H2O by charge transfer from potassium to oxygen. As a result, the desorption of H2O was inhibited, thus, became the kinetic barriers during the whole reaction process. K+ with localized form possessed suitable ability for O2 activation and weak adsorption of H2O, exhibiting enhanced catalytic activity. Inspired by the seesaw effect, a clear understanding of K+ effect on layered MnO2 towards O2 adsorption and H2O desorption was illustrated.

    更新日期:2017-11-10
  • Metal oxychlorides as robust heterogeneous Fenton catalysts for the sonophotocatalytic degradation of 2-nitrophenol
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-10
    Gamal M.S. ElShafei, A.M. Al-Sabagh, F.Z. Yehia, C.A. Philip, N.A. Moussa, Gh. Eshaq, A.E. ElMetwally

    Metal oxychlorides of Fe, Cu, Bi and Zn were prepared and tested in heterogeneous Fenton degradation of 20 ppm of 2-Nitrophenol (2-NP) in the presence of ultrasonic (US, 20 kHz), ultraviolet (UV, 6 W, λ = 254 nm), and US/UV coupled irradiations. The different experimental conditions including the catalysts dosages, hydrogen peroxide concentration, pH value, temperature, pollutant concentration and irradiation time were optimized and the reusability of the tested metal oxychlorides was investigated as well. The capability of 2-NP degradation follows the order US/UV > UV > US. The rate constant of degradation using sonophotocatalytic system was even higher than the sum of rates of individual systems due to its synergistic performance. Times of 30, 40, 50 and 50 min were respectively needed for Fe, Cu, Bi and Zn oxychlorides to accomplish complete degradation under the experimental conditions of 0.1 gL−1 solid, 5 mM H2O2, pH 7 and 25 °C. The rate constant of degradation followed the same order of mentioned metals with values of 0.15, 0.0871, 0.0806, and 0.0738 min−1 for Fe, Cu, Bi and Zn oxychlorides, respectively. The mechanism proposed considers a major role of produced hydroxyl radicals while the difference in band gap energy was emphasized in case of Bi and Zn oxychlorides.

    更新日期:2017-11-10
  • Removal of antibiotics, antibiotic-resistant bacteria and their associated genes by graphene-based TiO2 composite photocatalysts under solar radiation in urban wastewaters
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-10
    Popi Karaolia, Irene Michael-Kordatou, Evroula Hapeshi, Catherine Drosou, Yannis Bertakis, Dimitris Christofilos, Gerasimos S. Armatas, Labrini Sygellou, Thomas Schwartz, Nikolaos P. Xekoukoulotakis, Despo Fatta-Kassinos

    The present work investigated: (i) the removal of the antibiotics sulfamethoxazole (SMX), erythromycin (ERY) and clarithromycin (CLA); (ii) the inactivation of the total and antibiotic-resistant E. coli along with their regrowth potential after treatment; (iii) the removal of the total genomic DNA content; and (iv) the removal of selected antibiotic resistant genes (ARGs), namely sul1, ampC, ermB, mecA, as well as species-specific sequences, namely ecfX for Pseudomonas aeruginosa and enterococci-specific 23S rRNA, by graphene-based TiO2 composite photocatalysts under solar radiation in real urban wastewaters. TiO2-reduced graphene oxide (TiO2-rGO) composite photocatalysts were synthesized by two ex-situ synthesis methods, namely hydrothermal (HD) treatment and photocatalytic (PH) treatment, starting from graphene oxide and Aeroxide P25 TiO2, and were characterized with various techniques, such as XRD, FT-IR, Raman, XPS, SEM and surface area (BET). The potential of the synthesized TiO2-rGO composites for the removal of the abovementioned antibiotic-related microcontaminants was compared to the efficiency shown by pristine Aeroxide P25 TiO2 under simulated solar radiation, in real urban wastewater effluents treated by a membrane bioreactor. The results showed that TiO2-rGO-PH was more efficient in the photocatalytic degradation of ERY (84 ± 2%) and CLA (86 ± 5%), while degradation of SMX (87 ± 4%) was found to be slightly higher with Aeroxide P25 TiO2. It was also demonstrated that more than 180 minutes of treatment were satisfactory for the complete inactivation and complete absence of post-treatment regrowth of E. coli bacteria (<LOD) even 24 hours after the end of the treatment, for all examined photocatalytic materials. The least amount of regrowth at all experimental times was observed in the presence of TiO2-rGO-HD. Moreover, the synthesized graphene-based photocatalysts successfully removed ampC and significantly reduced ecfX abundance of Pseudomonas aeruginosa, but sul1, ermB and 23S rRNA for enterococci sequences were found to be persistent throughout treatment with all catalyst types. Finally, the total DNA concentration remained stable throughout the photocatalytic treatment (4.2–4.8 ng μL−1), indicating the high total genomic DNA stability in treated wastewater and its resistance to photocatalytic treatment.

    更新日期:2017-11-10
  • Simultaneous degradation of ciprofloxacin, amoxicillin, sulfathiazole and sulfamethazine, and disinfection of hospital effluent after biological treatment via photo-Fenton process under ultraviolet germicidal irradiation
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-10
    João A. Lima Perini, Adriano L. Tonetti, Cristiane Vidal, Cassiana C. Montagner, Raquel F. Pupo Nogueira

    A UVC-assisted photo-Fenton process was applied to hospital wastewater that had been submitted to anaerobic treatment. Low iron (10 μM; 0.56 mg L−1) and H2O2 (500 μM; 17 mg L−1) concentrations were used at the natural pH of the effluent (pH 7.4). Citric acid was employed as a complexation agent, at a 1:1 ratio, in order to maintain Fe3+ soluble at this pH, avoiding extra procedures and costs associated with acidification/basification of the final effluent. The anaerobic process quantitatively reduced the biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and total organic carbon (TOC), with low removal of antibiotics present in the wastewater. Degradation of the antibiotics ciprofloxacin, amoxicillin, sulfathiazole, and sulfamethazine was studied by spiking the anaerobic effluent at initial concentrations of 200 μg L−1. The antibiotics were efficiently degraded (80-95%) using UVC radiation alone, although under this condition, no DOC removal was observed after 90 min. Further additions of H2O2 and iron citrate increased the degradation rate constant (kobs), and 8% of DOC was removed. A lower pH resulted in higher kobs, although this was not essential for application of the photo-Fenton process. Irradiation with a germicidal lamp resulted in greater degradation of the antibiotics, compared to use of a black light lamp or sunlight, since the overall degradation was influenced by photolysis of the antibiotics, photolysis of H2O2, and the Fenton reaction. The photo-Fenton treatment could also be applied directly to the raw hospital wastewater, since no significant difference in degradation of the antibiotics was observed, compared to the anaerobic effluent. The photo-Fenton process under UVA and solar radiation reduced total coliforms and E. coli after 90 min. However, quantitative disinfection of these bacteria present in the Hospital effluent was only accomplished under UVC radiation.

    更新日期:2017-11-10
  • Facile Synthesis of Ternary TiO2 NP/Rh & Sb-codoped TiO2 NR//Titanate NT Composites Photocatalyst: Simultaneous Removals of Cd2+ Ions and Orange (II) Dye under Visible Light Irradiation (λ≥420 nm)
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-08
    Su-Gyeong Kim, Love Kumar Dhandole, Jeong-Muk Lim, Weon-Sik Chae, Hee-Suk Chung, Byung-Taek Oh, Jum Suk Jang

    In this study, rhodium and antimony doped nanorod (RS-TONR) was prepared by a molten salt solid state chemical reaction, and TiO2 nanorod and titanate nanotube (RS-TONR/TiNT) composite photocatalyst was synthesized by a hydrothermal method for different reaction times. The structural and chemical analyses of nanomaterials were performed by FE-SEM, XRD, UV-DRS and surface BET characterizations. The XRD and HR-TEM data confirmed that the as-synthesized material had mixed phase of TiO2 nanorod and Titanate nanotube (RS-TONR/TiNT). The photocatalytic activity of the composite photocatalyst was observed over the degradation of Orange (II) dye under visible light irradiation. Acid treatment and copper loading was conducted to enhance the surface property of RS-TONR/TiNT sample. The formation of TiO2 nanoparticle with anatase phase was observed by TEM and XRD analysis. The TEM mapping data also confirmed that copper oxide nanoparticles were well dispersed on the surface of titanate nanotubes. These dispersed nanoparticles were observed by XPS and STEM characterizations. The higher removal efficiency of Cd2+ ions was observed over the acid treated and untreated Cu3-TNP/TiNT/RS-TONR in the presence of Orange (II) dye. A higher photocatalytic activity of acid treated and 3 wt% CuxO/RS-TONR/TiNT was simultaneously obtained in the presence of cadmium ions during the degradation of Orange (II) dye.

    更新日期:2017-11-10
  • Feasibility of application of iron zeolites for high-temperature decomposition of N2O under real conditions of the technology for nitric acid production
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-07
    Edyta Tabor, Galina Sádovská, Milan Bernauer, Petr Sazama, Jana Novaková, Vlastimil Fila, Tomáš Kmječ, Jaroslav Kohout, Karel Závěta, Zdeněk Sobalík

    The long-term stabilities of a group of iron zeolites with MFI, *BEA, and FER structures and similar Fe/Al ratios were evaluated to assess their performance as catalysts for N2O decomposition. Conditions relevant for the application of the catalyst at the secondary level for N2O elimination, i.e., directly after the NH3 oxidation step of the process of nitric acid production, were investigated. These conditions included reaction temperatures of up to 900 °C and the presence of high concentrations of water vapour, oxygen, and NO. The focus of the study was the comparison of the MFI and *BEA zeolites with the FER-based zeolite, a catalyst established as relatively stable under such conditions. The structural analysis of the individual zeolite frameworks and iron species involved a combination of several methods, and provided insight into the framework modification as well as identification and semiquantitative determination of the individual iron species. In the zeolite catalysts, these iron species were in the form of either isolated Fe(II) and Fe(III)-oxo ions, polynuclear Fe(III)-oxo complexes, or small Fe oxide particles. None of the zeolite structures displayed a high extent of structural collapse of the framework; thus, structural collapse does not explain the observed decrease in activity. An investigation of the kinetics of the N2O decomposition, both before and after ageing under relevant reaction conditions, proved the dominant role of isolated Fe(II) ions that were accessible to the reacting gas-phase molecules. The kinetic study also identified the differences in the ability of the three zeolites to stabilize the active sites in individual framework types during long-term exposure to challenging reaction conditions. It has been shown that, while the isolated Fe(II) ions were present in adequate concentration for N2O decomposition activity at the relevant temperature region in all three zeolite-based catalysts, the MFI and *BEA zeolites were not able to effectively stabilize the active iron structure during ageing for over 12 days. In contrast, the FER framework survived a test for over 24 days. The iron species formed in MFI and *BEA zeolites during ageing were mostly large FeOx species and displayed very low activity that approached the activity of FeOx clusters supported on SiO2.

    更新日期:2017-11-10
  • Photocatalytic reduction of CO2 on Cu2O-loaded Zn-Cr layered double hydroxides
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-07
    Haoyang Jiang, Ken-ichi Katsumata, Jeong-soo Hong, Akira Yamaguchi, Kazuya Nakata, Chiaki Terashima, Nobuhiro Matsushita, Masahiro Miyauchi, Akira Fujishima

    A series of Cu2O-loaded Zn-Cr layered double hydroxides (LDHs) was prepared via an in situ reduction process from Cu-Zn-Cr ternary LDHs and applied to the photoreduction of CO2. The formation of Cu2O nanoparticles and the preservation of the LDH structure was confirmed by X-ray diffraction and transmission electron microscopy. Among the loaded LDHs, the 0.1Cu2O@Zn1.8Cr LDH exhibited optimal activity for the conversion of CO2 into CO in pure water and was superior to both the corresponding Cu-Zn-Cr ternary LDH and pristine Zn2Cr LDHs. In addition, the production of CO was further promoted by increasing the solubility of CO2 using a nano-bubble solution instead of pure water. The loaded Cu2O nanoparticles probably function as effective electron traps, promoting charge separation and providing active sites for CO2 reduction.

    更新日期:2017-11-10
  • Ce0.3Zr0.7O1.88N0.12 Solid Solution as a Stable Photocatalyst for Visible Light Driven Water Splitting
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-06
    Yu Lei Wang, Jia Min Jin, Yu Hang Li, Xue Lu Wang, Bo Zhang, Xiwen Gong, Hai Feng Wang, Ai Ping Chen, Li Rong Zheng, P. Hu, Hua Gui Yang

    The search of efficient and stable photocatalysts for the evolution of hydrogen from water using solar energy is of great importance for material science today. Limited by the relatively inferior stability of oxynitrides, the availability of these visible-light-response materials in photocatalysis is still far below what is expected. Here we report a novel oxynitride Ce0.3Zr0.7O1.88N0.12 as an efficient and stable H2-evolving photocatalyst under visible light irradiation, which can further enable overall water splitting by coupling with an O2-evolving photocatalyst via Z-scheme. Experimental and theoretical results together reveal that the origin of the excellent activity and stability of Ce0.3Zr0.7O1.88N0.12 photocatalyst can be attributed to the improved separation rate of photoexcited charge carriers by surface and sub-surface oxygen vacancies. The present study provides a strategy to engineer efficient and stable photocatalysts, and the oxynitride mentioned above could act as a promising candidate of H2-evolving photocatalyst for designing a prominent Z-scheme photocatalytic system.

    更新日期:2017-11-10
  • Transformation of limonene into p-cymene over acid activated natural mordenite utilizing atmospheric oxygen as a green oxidant: A novel mechanism
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-06
    Dimitra Makarouni, Sotiris Lycourghiotis, Eleana Kordouli, Kyriakos Bourikas, Christos Kordulis, Vassilis Dourtoglou

    Natural mordenite originated from volcanic soils in Greek islands was treated with sulfuric acid aqueous solutions of different concentrations and solid mass/solution volumes. The samples were characterized using various techniques (N2-physisorption, XRD, ATR-FTIR, SEM-EDS, TEM, Microelectrophoresis, Equilibrium pH) and tested in the transformation of limonene into p-cymene in the presence of atmospheric air at various temperatures and reaction times. The acid treatment is causing the removal of sodium oxide located inside the framework micropores and the small inter-fiber mesopores. This, in turn, increases drastically the BET specific surface area and unmasks negatively charged surface sites which are transformed into acid sites by adsorbing H+/H2O+ ions. The relatively low extent removal of Al3+ ions does not disturb the framework of natural mordenite nor its fibrous morphology. The development of micropores and small mesopores surface area and surface acid sites are transforming the catalytically inactive natural mordenite into very active catalysts. The increase in the conversion and the yield of p-cymene follows the increase in the BET specific surface area. A novel mechanism was experimentally established involving a catalytic step followed by a non catalytic one. The first step involves adsorption of limonene on acid sites via the exocyclic double bond to form the more stable tertiary carbenium ion from which terpinolenes, terpinenes and “polymeric species” are formed. The “transition state shape selectivity” manifested by the catalysts studied does not allow the formation of intermediate disproportionation products. In the second step, catalyst-free aromatization and “polymerization” of terpinolenes and terpinenes were found to occur. The aromatization was proposed to proceed by abstraction of an allylic hydrogen resulting to free radical (R<img border="0" alt="radical dot" src="https://cdn.els-cdn.com/sd/entities/rad">) followed by combination with O2 and radical chain propagation to yield allylic peroxides ([ROO<img border="0" alt="radical dot" src="https://cdn.els-cdn.com/sd/entities/rad">]) which by elimination of (HOO<img border="0" alt="radical dot" src="https://cdn.els-cdn.com/sd/entities/rad">) lead to the production of p-cymene. Moreover, high molecular weight compounds may be formed as radicals are combined to alkyl and peroxyl dimmers that may be polymerized. The experimental parameters concerning the acid treatment and reaction conditions were optimized for maximizing the amount of the produced p-cymene keeping as low as possible the amount of the produced polymeric species.

    更新日期:2017-11-10
  • Desilicated NaY zeolites impregnated with magnesium as catalysts for glucose isomerisation into fructose
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-06
    I. Graça, M.C. Bacariza, A. Fernandes, D. Chadwick

    The impact of desilication on the performance of a series of alkali-treated NaY zeolites impregnated with 5 wt.% of magnesium for glucose isomerisation into fructose has been studied. Desilication at different NaOH concentrations increases the mesoporous volume and external surface area, without compromising microporosity and crystallinity. The observed reduction of the microporous volume due to magnesium impregnation was found to decrease for the alkali-treated zeolites. Higher density and strength of basic sites and stronger magnesium-support interaction were also achieved with the treatment. These improved properties resulted in a significant increase of both glucose conversion and fructose yield on the magnesium-doped desilicated zeolites. Glucose conversion continuously increases with desilication (28-51%), whereas fructose yield passes through a maximum (35%) at low desilication levels. Among the prepared desilicated samples, low-severity alkali-treated zeolites also show lower deactivation in consecutive reaction runs, as well as superior regeneration behaviour. Thus, hierarchical NaY zeolites impregnated with magnesium could be favourably used for glucose isomerisation into fructose if suitable alkaline treatment conditions are selected, with low-severity treated NaY zeolites being the best choice. Higher fructose productivities were achieved for the low-severity desilicated zeolites than for higher magnesium content NaY zeolites reported previously, leading to a lower Mg requirement.

    更新日期:2017-11-10
  • Carbon Nanotubes Covalent Combined with Graphitic Carbon Nitride for Photocatalytic Hydrogen Peroxide Production under Visible Light
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-04
    Shen Zhao, Tao Guo, Xia Li, Tongguang Xu, Bo Yang, Xu Zhao
    更新日期:2017-11-05
  • Unique Role of Mössbauer Spectroscopy in Assessing Structural Features of Heterogeneous Catalysts
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-03
    Xuning Li, Kaiyue Zhu, Jifeng Pang, Ming Tian, Jiayi Liu, Alexandre I. Rykov, Mingyuan Zheng, Xiaodong Wang, Xuefeng Zhu, Yanqiang Huang, Bin Liu, Junhu Wang, Weishen Yang, Tao Zhang
    更新日期:2017-11-05
  • Facile Synthesis of Heterostructured YVO4/g-C3N4/Ag Photocatalysts with Enhanced Visible-Light Photocatalytic Performance
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-11-03
    Yu Gao, Junying Lin, Qingzhe Zhang, He Yu, Fu Ding, Baotong Xu, Yaguang Sun, Zhenhe Xu
    更新日期:2017-11-05
  • Visible light driven water splitting over CaTiO3/Pr3+-Y2SiO5/RGO catalyst in reactor equipped artificial gill
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-31
    Wei Gao, Wenyan Zhang, Bin Tian, Wenlong Zhen, Yuqi Wu, Xuqiang Zhang, Gongxuan Lu
    更新日期:2017-11-01
  • NiMo-Ceria-Zirconia catalytic reforming layer for solid oxide fuel cells running on a gasoline surrogate
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-31
    Kai Zhao, Xiaoxue Hou, Qusay Bkour, M. Grant Norton, Su Ha
    更新日期:2017-11-01
  • 更新日期:2017-11-01
  • Highly selective oxidation of furfuryl alcohol over monolayer titanate nanosheet under visible light irradiation
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-31
    Hao Wang, Yujie Song, Jinhua Xiong, Jinhong Bi, Liuyi Li, Yan Yu, Shijing Liang, Ling Wu
    更新日期:2017-11-01
  • Graphene supported NiO/Ni nanoparticles as efficient photocatalyst for gas phase CO2 reduction with hydrogen
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-31
    Diego Mateo, Josep Albero, Hermenegildo García
    更新日期:2017-11-01
  • Photocatalytic CO2 Conversion on Highly Ordered Mesoporous Materials: Comparisons of Metal Oxides and Compound Semiconductors
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-29
    Yoon Yun Lee, Han Sol Jung, Ji Man Kim, Yong Tae Kang
    更新日期:2017-10-30
  • Synthesis, properties and mechanism of the ion exchange resins based on 2-methyl-5-vinylpyridine and divinylbenzene in the catalytic disproportionation of trichlorosilane
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-29
    Andrey V. Vorotyntsev, Anton N. Petukhov, Dmitriy A. Makarov, Evgeny N. Razov, Ilya V. Vorotyntsev, Alexander V. Nyuchev, Natalia I. Kirillova, Vladimir M. Vorotyntsev
    更新日期:2017-10-30
  • A study on the deactivation and reactivation of a Ni/Al2O3 aldehyde hydrogenation catalyst: Effects of regeneration on the activity and properties of the catalyst
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-28
    Sinqobile N.V. Mahlaba, Jignesh Valand, Abdul S. Mahomed, Holger B. Friedrich
    更新日期:2017-10-30
  • Zirconia-Supported Tungstophosphoric Heteropolyacid as Heterogeneous Acid Catalyst for Biodiesel Production
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-28
    Juan Alcañiz-Monge, Bouchra El Bakkali, Guido Trautwein, Santiago Reinoso
    更新日期:2017-10-30
  • Highly-efficient Photocatalytic Disinfection of Escherichia coli under Visible Light Using Carbon Supported Vanadium Tetrasulfide Nanocomposites
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-28
    Baogang Zhang, Shiqiang Zou, Ruquan Cai, Min Li, Zhen He
    更新日期:2017-10-30
  • Novel V2O5-CeO2-TiO2-SO42− nanostructured aerogel catalyst for the low temperature selective catalytic reduction of NO by NH3 in excess O2
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-28
    Jihene Arfaoui, Abdelhamid Ghorbel, Carolina Petitto, Gerard Delahay
    更新日期:2017-10-28
  • Hydroxyapatite supported bimetallic cobalt and nickel catalysts for syngas production from dry reforming of methane
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-27
    Phan Thanh Son, Sane Abdoul Razac, Bruna Rêgo de Vasconcelos, Ange Nzihou, Patrick Sharrock, Didier Grouset, Pham Minh Doan
    更新日期:2017-10-28
  • Solar photoelectro-Fenton treatment of a mixture of parabens spiked into secondary treated wastewater effluent at low input current
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-27
    Juliana R. Steter, Enric Brillas, Ignasi Sirés
    更新日期:2017-10-28
  • Rare earth ions doped K2Ta2O6 photocatalysts with enhanced UV–vis light activity
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-27
    Anna Krukowska, Michal Jerzy Winiarski, Judyta Strychalska-Nowak, Tomasz Klimczuk, Wojciech Lisowski, Alicja Mikolajczyk, Henry P. Pinto, Tomasz Puzyn, Tomasz Grzyb, Adriana Zaleska-Medynska
    更新日期:2017-10-28
  • Egg-shell membrane reactors for nitrite hydrogenation: manipulating kinetics and selectivity
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-27
    Roger Brunet Espinosa, Damon Rafieian, Rolf Sybren Postma, Rob G.H. Lammertink, Leon Lefferts
    更新日期:2017-10-28
  • Synergistic Ag/TiO2-N Photocatalytic System and Its Enhanced Antibacterial Activity towards Acinetobacter baumannii
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-26
    Guoxiang Yang, Haibo Yin, Wenhua Liu, Yuping Yang, Quan Zou, Liulin Luo, Huiping Li, Yuning Huo, Hexing Li
    更新日期:2017-10-27
  • Role of oxygen vacancies in photocatalytic water oxidation on ceria oxide: Experiment and DFT studies
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-26
    Yong-Chao Zhang, Zheng Li, Lei Zhang, Lun Pan, Xiangwen Zhang, Li Wang, Fazal-e-Aleem, Ji-Jun Zou
    更新日期:2017-10-27
  • Ti3+ Self-Doped TiO2 via Facile Catalytic Reduction over Al(acac)3 with Enhanced Photoelectrochemical and Photocatalytic Activities
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-26
    Jordan Lee, Zhong Li, Liangzhu Zhu, Songhai Xie, Xiaoli Cui
    更新日期:2017-10-27
  • Chemical CO2 Recycling via Dry and Bi Reforming of Methane Using Ni-Sn/Al2O3 and Ni-Sn/CeO2-Al2O3 Catalysts
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-19
    T. Stroud, T. Smith, E. Le Saché, J.L. Santos, M.A. Centeno, H. Arellano-Garcia, J.A. Odriozola, T.R. Reina
    更新日期:2017-10-20
  • Active and durable alkaline earth metal substituted perovskite catalysts for dry reforming of methane
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-19
    Srikanth Dama, Seema R. Ghodke, Richa Bobade, Hanmant R. Gurav, Satyanarayana Chilukuri
    更新日期:2017-10-20
  • New Understandings of Ethanol Oxidation Reaction Mechanism on Pd/C and Pd2Ru/C Catalysts in Alkaline Direct Ethanol Fuel Cells
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-18
    Junsong Guo, Rongrong Chen, Fu-Chun Zhu, Shi-Gang Sun, Hebe M. Villullas
    更新日期:2017-10-18
  • Preparation of hydrodesulfurization catalysts using MoS3 nanoparticles as a precursor
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-18
    Yang Gao, Wei Han, Xiangyun Long, Hong Nie, Dadong Li
    更新日期:2017-10-18
  • Hydrogenation of sodium hydrogen carbonate in aqueous phase using Metal / activated carbon catalysts
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-17
    Edelmira González, Cristian Marchant, Catherine Sepúlveda, Rafael García, I.Tyrone Ghampson, Nestor Escalona, Jose Luis García-Fierro
    更新日期:2017-10-17
  • Effective separation of carriers and the redox sites in Ta3N5/Bi photocatalyst for promoting conversion of CO2 into CH4
    Appl. Catal. B Environ. (IF 9.446) Pub Date : 2017-10-16
    Shaomang Wang, Yuan Guan, Lei Lu, Zhan Shi, Shicheng Yan, Zhigang Zou
    更新日期:2017-10-17
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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