Rapid synthesis of tetragonal zirconia nanoparticles by microwave-solvothermal route and its photocatalytic activity towards organic dyes and hexavalent chromium in single and binary component systems

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Abstract

In this paper, tetragonal zirconia nanoparticles (ZrO2 NPs) were synthesized via rapid microwave mediated solvothermal method in just 10 min reaction time. A combination of X-ray diffraction, Raman, Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM) and XPS analysis confirmed the formation of single phase tetragonal ZrO2 with average crystallite size ∼ 10 nm. The band gap energy of the synthesized ZrO2 was measured to be 3.67 eV. The photocatalytic behaviour of synthesized ZrO2 NPs was examined for the degradation of two anionic dyes (Eosin Yellow and Bromophenol Blue) and the reduction of Cr(VI) under UV light irradiation. ZrO2 adsorbed and degraded both the dyes within 120 min. At 20 mg/L concentration, more than 96 % of Cr(VI) was reduced to Cr(III) within 60 min. Under the operating conditions, both the degradation of dyes and reduction of Cr(VI) followed pseudo first-order kinetics and rate constant values were inversely dependent on the initial dye concentration. The probable mechanism for the degradation has been proposed through advanced oxidation process. ZrO2 NPs was also found efficient for simultaneous remediation of dye and Cr(VI). The photoreduction of Cr(VI) to Cr(III) was further confirmed from XPS analysis of ZrO2 NPs after chromium reduction.

Introduction

Nanometric ZrO2 is an important class of multifunctional material with wide range of technological and interdisciplinary applications in various fields such as transparent and optical devices, fuel cells, sensor, coating, advanced ceramics, catalysis/photocatalysis, sorbent, energy conversion and storage and biomedical applications [[1], [2], [3], [4], [5], [6], [7], [8], [9], [10]]. ZrO2 exhibits three polymorphic forms as monoclinic (m), tetragonal (t) and cubic (c) with temperature dependent stabilities in the range RT – 1170 °C, 1170–2370 °C and above 2370 °C, respectively. ZrO2 with relatively large band gap energy (∼ 5.0 eV), high chemical and photothermal stability, high corrosive resistance and negative value of the conduction band potential (-1.0 V vs. NHE), shows good photocatalytic performance under UV light irradiation for various heterogeneous photochemical reactions, as well as water splitting [[11], [12], [13]]. However, the wide bandgap and the recombination of photogenerated electron-hole pairs prevent its photocatalytic applications in the visible light region. It has been reported that besides doping with metals/non-metals, the synthetic routes greatly influence the band gap energy of ZrO2 [1,10,14,15]. The band gap values of ZrO2 can be narrowed down to 2.3 eV depending on the preparation methods [1,14,15]. Recently, oxygen-deficient black zirconia (ZrO2-x) with bandgap as low as ∼1.5 eV has been prepared from white ZrO2 via a controlled magnesiothermic reduction in 5 % H2/Ar for solar light absorption [16]. As a result, studies on photocatalytic performance of ZrO2 NPs have attracted a great deal of interest recently [8,[2], [3], [4], [5], [6], [7], [8], [9], [10],14,[16], [17], [18], [19], [20], [21], [22], [23]]. It has also been observed that the catalytic performance of ZrO2 is not only sensitive to its crystal phase but also related to its size and morphology [9,10,24,25]. For instance the metastable t-ZrO2 exhibits superior catalytic and mechanical properties than when it is in the monoclinic phase (m-ZrO2) [24]. The phase formation and the morphology of the ZrO2 nanoparticles are largely dependent on the methods of synthesis. Several physical and chemical methods such as sol-gel, microwave, hydrothermal, solvothermal, co precipitation, surfactant templating, flame spray pyrolysis etc. have been effectively used for controlled synthesis of t-ZrO2 with different morphology including nanoparticles, nanorods, nanotubes etc. at mild temperature [1,3,[19], [20], [21], [22],[26], [27], [28], [29], [30], [31], [32], [33]]. Synthesis of t-ZrO2 with low band gap energy showing higher photocatalytic activity is still a challenge.

Ultrafine polymer stabilized nanocrystalline t-ZrO2 powders and t-ZrO2 NPs have been successfully synthesised by microwave-assisted hydrothermal [1] and microwave-assisted sol-gel [30] methods. Hydrothermal route has been effectively used in the preparation of tetragonal ZrO2 NPs [31] and star-like ZrO2 nanostructures [21]. Calcinations of flower-like hierarchical ZrO2, prepared by hydrothermal process using Zr(SO4)2.4H2O and CH3COONa as the raw materials, yielded tetragonal zirconia nanostructures [22]. To the best of our knowledge, this is the only report discussing about the synthesis of t-ZrO2 via rapid one-step microwave-assisted solvothermal route. Microwave assisted synthesis has advantages of production of smaller nanoparticles with narrow size distribution in short duration. The present work is a part of our ongoing research to use microwave-assisted hydrothermal/solvothermal route for the preparation of various potential inorganic ceramics [34,35].

Degradation of organic dyes under UV or visible light irradiation has been commonly used to evaluate the catalytic efficiency of different photocatalysts [[36], [37], [38], [39], [40]]. Dyes, a common constituent of waste water, are indiscriminately discharged as effluents into the environment by different industries such as textile, leather, food and paper. Due to their toxicity and possible carcinogenicity and mutagenicity, it is essential to remove the dye material from effluents before their discharge into the water stream. Heterogeneous photocatalytic treatment using a wide variety of photocatalytic materials have been extensively used to solve this problem.

Hexavalent chromium (Cr(VI)), another common inorganic water contaminant, has been widely used in leather tanning, dye production industries besides other industries such as steel production, electroplating, etc. [41,42]. Cr(VI) is not only highly toxic but also carcinogens posing danger to human health and environment. Apart from conventional methods of treatment, such as chemical reduction/precipitation, ion exchange, electrolysis, adsorption, etc., removal of Cr(VI) through photocatalytic reduction has been explored using different photocatalysts [23]. Photoreduction of Cr(VI) at pH > 6.0 precipitates the reduced Cr(III) species as its hydroxide; the catalyst can be recovered by subsequent acidification. In this context, removal of both dyes and hexavalent chromium is important as well as beneficial.

In this paper, we reported the synthesis of t-ZrO2 NPs via a rapid and one-step microwave-solvothermal route characterised by the use of various physicochemical methods. Further, the photocatalytic efficiency t-ZrO2 NPs was evaluated for degradation of two potentially harmful and structurally different dyes such as bromophenol blue and eosin yellow as well as reduction of Cr(VI).

Section snippets

Materials

Analytical grade chemicals and reagents were used as received without further purification. Zirconyl oxynitrate (CDH), 1,4-butanediol (Spectrochem) were used for synthesis of ZrO2. Bromophenol Blue (BRB), Eosin Yellow (EY) and K2Cr2O7 (CDH) were used as received in photocatalytic experiments. Double distilled water was used in all experiments.

Synthesis of ZrO2

ZrO2 nanoparticles (NPs) were synthesised through microwave mediated solvothermal process. In a typical lot, ZrO(NO3)2 (0.70 g) and 1,4 butanediol (20 mL)

XRD analysis

The XRD patterns of the synthesized ZrO2 NPs are shown in Fig. 1. The most emerging diffraction peaks in the XRD patterns are indexed to tetragonal ZrO2 (t-ZrO2) phase corresponding to (111), (200), (220), (311), and (222) crystalline planes (JCPDS Card No. 02-0733) and also matches well with those reported for t-ZrO2 [21,24,[27], [28], [29]]. Peaks of no other phases (especially, monoclinic phase) are observed in the XRD patterns indicating formation of a single crystalline tetragonal phase.

Conclusion

Single phase tetragonal ZrO2 NPs (t-ZrO2) was successfully synthesised by microwave solvothermal method and its structural, morphological and optical behaviours were investigated. Tetragonal phase purity of synthesised sample was confirmed from XRD, Raman and HR-TEM analyses. The ZrO2 NPs showed band gap energy of 3.67 eV which is comparable to those prepared by other methods with similar size. The photocatalytic efficiency of as synthesized samples was tested for degradation of two

CRediT authorship contribution statement

Sanjibani Mishra: Investigation, Visualization. A.K Debnath: Resources, Data curation. K.P Muthe: Resources, Data curation. Nigamananda Das: Supervision, Methodology, Writing - review & editing. P. Parhi: Supervision, Methodology, Writing - original draft, Project administration, Funding acquisition.

Declaration of Competing Interest

The authors report no declarations of interest.

Acknowledgements

This work is funded and supported by BRNS, India (Grant no. 2013/ 37C/53/BRNS/2152). Miss S. Mishra acknowledges BRNS for fellowship. Financial support to the Centre of Excellence in Environment and Public Health by Government of Odisha under OHEPEE (Grant No. 26913/HED/HE-PTC-WB-02-17) is gratefully acknowledged.

References (63)

  • Y. Gao et al.

    L-lysine-Assisted synthesis of ZrO2 nanocrystals and their application in photocatalysis

    Mater. Res. Bull.

    (2017)
  • R. Dwivedi et al.

    Microwave assisted sol–gel synthesis of tetragonal zirconia nanoparticles

    J. Alloys Compd.

    (2011)
  • M. Verma et al.

    Synthesis of ZrO2 nanoparticles using reactive magnetron sputtering and their structural, morphological and thermal studies

    Mater. Chem. Phys.

    (2018)
  • S. Mishra et al.

    Rapid microwave–hydrothermal synthesis of CeO2 nanoparticles for simultaneous adsorption/ photodegradation of organic dyes under visible light

    Optik

    (2018)
  • W. Huang et al.

    Constructing novel ternary composites of carbon quantum dots/Bi2MoO6/ graphitic nanofibers with tunable band structure and boosted photocatalytic activity

    Sep. Purif. Technol.

    (2019)
  • S.D. Meetei et al.

    Polyol synthesis and characterizations of cubic ZrO2:Eu3+ nanocrystals

    J. Alloys Compd.

    (2012)
  • S. Manjunatha et al.

    Microwave assisted synthesis of cubic Zirconia nanoparticles and study of optical and photoluminescence properties

    J. Lumin. Appl.

    (2016)
  • W. Wu et al.

    Preparation, characterization and enhanced visible light photocatalytic activities of polyaniline/Bi3NbO7 nanocomposites

    J. Alloys Compd.

    (2012)
  • S. Kumar et al.

    Oxygen vacancy induced photoluminescence properties and enhanced photocatalytic activity of ferromagnetic ZrO2 nanostructures on methylene blue dye under ultra-violet radiation

    J. Alloys Compd.

    (2015)
  • L. Yu et al.

    Highly efficient Bi2O2CO3/BiOCl photocatalyst based on heterojunction with enhanced dye sensitization under visible light

    Appl. Catal. B Environ.

    (2016)
  • A.A. Abdel-Khalek et al.

    Visible light assisted photocatalytic degradation of crystal violet, bromophenol blue and eosin Y dyes using AgBr-ZnO nanocomposite

    Environ. Nanotechnol. Monitor. Manage.

    (2018)
  • J. Lin et al.

    Removal of phosphate from aqueous solution by a novel Mg(OH)2/ZrO2 composite: adsorption behaviour and mechanism

    Colloids Surf. A

    (2019)
  • N. Bashirom et al.

    Synthesis of freestanding amorphous ZrO2 nanotubes by anodization and their application in photoreduction of Cr(VI) under visible light

    Surf. Coat. Technol.

    (2017)
  • Y. Gao et al.

    Polyaniline-modified 3D-flower-like molybdenum disulfide composite for efficient adsorption/photocatalytic reduction of Cr (VI)

    J. Colloid Interface. Sci.

    (2016)
  • J. Liang et al.

    Photoluminescence of tetragonal ZrO2 nanoparticles synthesized by microwave irradiation

    Inorg. Chem.

    (2002)
  • J.H. Shim et al.

    Atomic layer deposition of yttria stabilized zirconia for solid oxide fuel cells

    Chem. Mater.

    (2007)
  • A. Sinhamahapatra et al.

    Mesoporous borated zirconia: a solid acid-base bifunctional catalyst

    Chemcatchem

    (2013)
  • P.A. Deshpande et al.

    Rapid synthesis of ultrahigh adsorption capacity zirconia by a solution combustion technique

    Langmuir

    (2011)
  • M.S. Dominguez et al.

    Synthesis of CeO2, ZrO2, CeO2.5ZrO2 5O2, and TiO2 nanoparticles by a novel oil-in-water microemulsion reaction method and their use as catalyst support for CO oxidation

    Catal. Today

    (2010)
  • S.N. Basahel et al.

    Influence of crystal structure of nanosized ZrO2 on photocatalytic degradation of methyl orange

    Nanosc. Res. Lett.

    (2015)
  • N.F. Zubair et al.

    A comprehensive thermodynamic and kinetic study of synthesized rGO-ZrO2 composite as a photocatalyst and its use as fuel additive

    J. Mol. Struct.

    (2019)
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      Citation Excerpt :

      The interest of ZrO2 as semiconductor for photocatalytic applications has increased because of its non-toxicity, chemical stability, low cost and environmental friendliness. Although various studies deal with the preparation of the ZrO2 photocatalyst, most of them have been dedicated to the photodegradation of dyes [21–34] while the degradation of other organic pollutants [35–39] or the hydrogen production [32,40,41] was less envisaged. However, up to date, no studies related to the photodegradation of formic acid over ZrO2 nanomaterials have been described in the literature.

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