Abstract
This study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.
1 Introduction
Research for green synthesis about nanomaterials by using natural biomaterials such as plants, flowers, and microorganisms is a new branch of nanotechnology known as green synthesis. Green synthesis of nanoparticles has many benefits such as cost-effectiveness, reduction of pollution as well as being eco-friendly (Zhu et al., 2018; Zinatloo-Ajabshir and Salavati-Niasari, 2015). The SrFe12O19– SrTiO3 nanocomposite has been proposed by green synthesis as a novel material. The natural plants that can extract biological capping agents have been green tea (Nadagouda et al., 2010), eucalyptus (Madhavi et al., 2013) and lemon juices. Lemon juice as a rich source of Citric and Ascorbic acid (vitamin C) was used to synthesize nanocomposites and nanoparticles (Ahmadian-Fard-Fini et al., 2020). In this study, the SrFe12O19–SrTiO3 nanocomposite was prepared by using lemon juice. The strontium ferrite, have been synthesized by different techniques such as sonochemistry (Palomino et al., 2016), hydrothermal method (Meng et al., 2016; Xia et al., 2013), co-precipitation (Ariaee et al., 2017; Auwal et al., 2016), sol-gel method (Wang et al., 2009a, 2009b) and sol-gel auto-combustion (Almessiere et al., 2018; Yang et al., 2009). Sol-gel auto-combustion method for synthesis of metals and alloys was proposed at a low temperature which is required for reaction, and the combustion does not need any external energy supply (Hua et al., 2011; Mir et al., 2012; Nabiyouni and Ghanbari, 2018; Salavati-Niasari et al., 2010). Traditional reactions for synthesis SrFe12O19 nanoparticles require a high calcining temperature (1200-1300°C), though the sol-gel auto-combustion method produces homogeneous nanoparticles at much lower calcination temperatures (Jacobo and Bercoff, 2013). The sol-gel auto-combustion synthesis has four steps. Firstly, formation of complexes in the solution, secondly, evaporation the water of the solution and gel formation thirdly, auto-combustion by heated and at the end, obtaining the nanoparticles (Deganello et al., 2009; Mali and Ataie, 2004).
A type of ferrites is spinel ferrites (Ahmadian-Fard-Fini et al., 2018), like M-type ferrite. M-type ferrite is an attractive magnetic material that has large saturation magnetization and high coercivity (Lahijani et al., 2018). Therefore it can find wide industrial applications in electronic components, magnetic memories, magnets, and sensors (Valenzuela, 2012). The strontium ferrite (SrFe12O19) is an M-type hexagonal ferrite (Hedayati et al., 2016, 2017a; Wohlfarth and Buschow, 1982) with large saturation magnetization and high coercivity. Also, it can be widely used for electronic components, high-density recording media, magnets, sensors, and microwave devices (Fang et al., 2000; Garcıa-Cerda et al., 2004).
The dielectric properties of strontium ferrite could be improved via the concatenation of perovskite strontium (SrTiO3). Perovskite-type has a general formula as ABO3. The A is a trivalent rare-earth and B is a 3d transition metal (Eskandari et al., 2019; Salavati-Niasari and Davar, 2006). Perovskites are usually used in environmentally friendly catalytic systems (Thornton et al., 1982). In this research, perovskite strontium has been synthesized using the sol-gel auto-combustion method.
In recent years, heterogeneous photocatalysis was developed as several forms, photodegradation of organizational pollutant have been recently the most investigated. SrTiO3 is cost-effective and its inert photostability compared to other semiconductor photocatalysts was considered higher than photocatalysts effect of other semiconductor (Gaya and Abdullah, 2008).
The present paper seeks to offer a viable heterogeneous photocatalytic degradation alternative for the degradation of organic pollutions in wastewater by using SrFe12O19–SrTiO3 nanocomposite. To acquire the desired photodegradation efficiency, combining diverse techniques and approaches might be essential. In this regard, adding magnetic properties needs to be established because by applying an external magnetic field, nanoparticles can be controlled and separated from the solution (Dong et al., 2015). The nanocomposite of SrFe12O19–SrTiO3 has been synthesized using combustion methodologies. It is thus worth carrying out a study of synthesizing the products of SrFe12O19 with doping SrTiO3.
2 Experimental
2.1 Materials
All the chemical materials that have been used in this experiment, have a very high purity and have been produced by Merck company, included iron nitrate monohydrate (Fe(NO3)3‧9H2O), strontium nitrate (Sr (NO3)2) (Garcıa-Cerda et al., 2004; Salavati-Niasari, 2004), ammonia (NH3) (Auwal et al., 2016; Salavati-Niasari, 2005a; Salavati-Niasari and Amiri, 2005), citric acid (C6H8O7) (Deganello et al., 2009), titanium isopropoxide (C12H28O4Ti), ethanol (C2H5OH), and other chemicals materials were used without further purification. In order to synthesize SrFe12O19 nanoparticles, deionized and distilled water used. The sample was prepared via green synthesis using juice of fresh lemon. Pieces of fresh lemon in lemon juice were washed and squeezed, and then the lemon juice was filtered.
2.2 Preparation of SrFe12O19 nanoparticles
SrFe12O19 nanoparticle was prepared by green synthesis using the sol-gel auto combustion method. First, 100 mL of lemon juice was heated at 50-100°C for 15 min and then solution was filtered to get the lemon extract. The starting reagents that used were stoichiometric amounts of 2.3 g of Fe(NO3)3‧9H2O and 0.2 g Sr(NO3)2 (molar ratio of Fe/Sr:12/2) were separately dissolved in 20 mL of deionized water at room temperature to form a clear hydrous solution (Garcıa-Cerda et al., 2004; Mohandes et al., 2010, 2014; Shabanian et al., 2014). The two above mentioned solutions were mixed together and then continuously were stirred using a magnetic stirrer. After 15 min, 15 mL lemon juice extract was added to the mixture (Almessiere et al., 2018). After stirring for 20 min, 5 mL NH3 was added drop wise in the pioneer solution until it became neutral (pH~7), as the solution was getting more and more viscous during heating until the water vaporized (Ariaee et al., 2017; Yousefi et al., 2011). The temperature was gradually increased to 150°C to remove the water remnant and a brownish solution was formed. Condensation reaction occurs between adjoining metal nitrates and citric acid. Its conclusion continued until the resulting solution known as a sol. The resultant sol on the hot heated stirrer was heated at 50-100°C under constant stirring until the water of solution was evaporated making a viscous liquid called gel. Then, the gel auto-ignited suddenly and finally evaporated releasing black ash and the exhaust of CO2, N2, and H2O gases. The SrFe12O19 powder was washed with deionized water and then the collected powder was dried in the oven at 80°C for 48 h. The resulting nanoparticles were calcined at 850°C for 120 min to obtain single-phase SrFe12O19.
2.3 Preparation of SrTiO3 nanoparticles
In order to fabricate nanocrystals of perovskite strontium by auto-combustion sol-gel, 0.22 g of Sr(NO3)2 was slowly dissolved in 50 mL of ethanol by a magnetic stirrer. In the next step, 0.3 g of C12H28O4Ti added to the above solution. After 10 min, 5 mL of lemon juice was added to the solution at room temperature as a gel agent. A quantity of 5 mL of NH3 as a pH adjuster in 7 was added to the solution. The solution was heated until applied after self-ignition flaring and burning smoke occurs. Then the gray powder was obtained by the self-combustion sol-gel process. The resulting product was rinsed by deionized water and then centrifuged. The nanoparticles dried in an oven at 80°C for one day, and finally, the resulting powder was calcified at 500°C for 2 h inside the oven.
2.4 Synthesis of SrFe12O19–SrTiO3 nanocomposites (50/50% w/w)
At first for the production of hexaferrite strontium-perovskite strontium nanocomposite, 0.1 g SrFe12O19 nanoparticles that were synthesized by using the auto-combustion method was dissolved in 100 mL of ethanol at room temperature. Then, 0.1 g of Sr(NO3)2 and 0.1 g C12H28O4Ti were dissolved by a mechanical stirrer on the styrene at room temperature for 3 h. Then the solution was continuously stirred using a mechanical stirrer for getting a better homogeneity for 3 h. 15 mL of lemon juice was added to the solution as a capping agent. After stirring for 20 min, the pH value of the solution was adjusted to 7 with adding 7 mL ammonia solution. The green solution was evaporated slowly at 80°C until a little of sol remained as the solution was getting vicious and remained water vaporization. The temperature was increased to 150°C until starting the auto-combustion. The product powder was obtained by filtering and washing the suspension with deionized water. The obtained black powder contained SrTiO3–SrFe12O19 (with weight ratio 1:1) and the nanocomposite placed in a dryer oven in order to dry at 80°C for 48 h. Figure 1 shows the schematic for the experimental setup for nanoparticle and nanocomposite preparation.
Schematic of nanoparticle SrFe12O19 and nanocomposite SrFe12O19–SrTiO3 preparation.
3 Characterization
X-ray diffraction patterns were recorded by using a Philips (Amsterdam, Netherlands) X-ray diffractometer using CuKα radiation (λ = 1.54 Å). SEM images and EDX elemental analysis were obtained by using a LEO (Cambridge, UK) instrument (Model 1455VP). Vibration Sampling Magnetometer was used to investigate the magnetic properties and hysteresis loop of synthesized materials. The magnetic measurements were carried out at room temperature using a VSM (MeghnatisKavir Kashan Company, Iran) in an applied magnetic field sweeping between ±10000 Oe. To identify chemical bonds between the atoms the FTIR by Thermal camera BRUKER model ALPHA (Germany) instrument using KBr pellets was used. The optical properties of the particles from the UV-Vis Shimadzu UV-2600m (China) have been used.
4 Results and discussion
4.1 XRD analysis
The crystalline structure and compound formation of prepared and post sintered samples were studied using X-Ray diffraction in the 2θ range 10-80° with step size 0.02° at room temperature (Salavati-Niasari, 2006; Salavati-Niasari and Davar, 2006).
The average crystallite size of the nanocrystals was calculated by Debye-Scherrer formula (Khorsand Zak et al., 2011; Salavati-Niasari, 2006):
where D is mean crystallite size, θ is the Bragg diffraction angle and β is the width of the observed diffraction peak at its half maximum intensity (FWHM), k is the shape factor (about 0.9), and λ is the X-ray wavelength (0.154 nm) (Khorsand Zak et al., 2011).
The broadening of peaks may be related to strain due to crystal imperfections and distortion. Using the Williamson-Hall method, it is assumed that size and strain broadening are additive components of the total integral breadth of a Bragg peak (Hedayati et al., 2017b; Mousavi-Kamazani et al., 2016; Safardoust-Hojaghan and Salavati-Niasari, 2017). The Williamson-Hall formula is expressed in Eq. 2:
where ε is a strain of crystal lattice. With the drawing of the βcosθ diagram in terms of sinθ the optimum line equation can find the size of the crystallite and the network strain.
The XRD pattern of the SrFe12O19 nanoparticles calcinationsat 850°C was investigated in Figure 2. The XRD pattern of SrFe12O19 has shown a pattern of pure hexagonal phase (JCPDS No. 24-1207) with P63/mmc space group that is pure hexaferrite strontium nanoparticles. The mean value of the nano-crystalline of SrFe12O19 was calculated to be 56 nm using the Debye-Scherrer’s formula and 55 nm by the Williamson-Hall method. Also, the strain of the network was equal to 0.000175.
XRD pattern of the SrFe12O19 samples prepared at calcination temperature of 850°C.
The X-ray diffraction of the SrTiO3 nanoparticle which calcinated at 500°C, was determined and shown in Figure 3. This shows the cubic phase (JCPDS No. 05-0634) with the Pm3m space group was prepared which is consistent with pure perovskite strontium. The mean value of the nano-crystalline size of SrTiO3 was calculated to be 40 nm using the Debye-Scherrer’s formula, 49 nm by the Williamson-Hall’s formula and the strain of the grid was 0.00075.
XRD spectrum of SrTiO3 nanoparticle that calcinate at 500°C.
The XRD of the composition of the SrFe12O19–SrTiO3 nanocomposite was also investigated. Figure 4 confirms the presence of both SrFe12O19 and pure perovskite strontium phase. The average crystalline size for SrFe12O19, SrTiO3 nanoparticles, SrFe12O19–SrTiO3 nanocomposite, and ε were calculated via Debye-Scherrer’s formula and Williamson-Hall method and are shown in Table 1.
XRD patterns of SrFe12O19–SrTiO3 nanocomposite.
Crystaline size for XRD paterns.
| D. Scherrer (nm) | D. Williamson-Hall (nm) | ε strain | |
|---|---|---|---|
| SrFe12O19 calcination at 850°C | 56 | 55 | 0.000175 |
| SrTiO3 calcination at 500°C | 40 | 49 | 0.00075 |
| SrFe12O19–SrTiO3 | 54 | 59 | 0.00055 |
4.2 FTIR analysis
Figure 5 shows the FTIR spectrum of SrFe12O19 nanoparticles that calcinated at 850°C in the range of 400 to 4000 cm–1. The peak near 3420 cm−1 is due to the stretching modes of the O–H band of the free or adsorbed water (Davar et al., 2010; Salavati-Niasari et al., 2005b). The weak band near 1632 cm–1 is attributed to the H–O–H bending vibration mode. The Peak corresponding to the Fe–O was observed at 593 cm–1 and the peak in 435 cm–1 is indicative of Sr–O.
FT-IR spectrum of SrFe12O19 calcinated at 850°C.
The FTIR spectrum of SrTiO3 nanoparticles that calcinated at 500°C is shown in Figure 6. The band at 566 cm−1 was assigned to Ti–O stretching vibration mode and peak in 439 cm–1 indicates Sr–O. The broadband at 3384 cm−1 was assigned to the O–H stretching vibration and the weak band near 1629 cm−1 was assigned to vibration mode of H–O–H bending.
FT-IR spectrum of SrTiO3 calcinated at 500°C.
FTIR spectrum of the SrFe12O19–SrTiO3 nanocomposite is shown in Figure 7. The spectrum shows bands near 3269 cm−1 which are attributed to the stretching modes and O–H bending vibrations of water. In addition, absorption peaks near 1393 cm−1 and 1356 cm−1 refer to Ti–O–Ti vibrations. The main Absorption peaks in 434 cm−1 and 550 cm−1 appertain to the Fe–O bands in SrFe12O19 and the peak of 591 cm−1 belongs to Ti–O in SrTiO3. The absorption peak at 759 cm−1 belongs to the Ti–O–Sr vibrations in the SrTiO3. The peak at 1709 cm−1 is the C–O and at 1626 cm−1 is tensile transplants H–O–H. The absorption peak at 1393 cm−1 is C=O and at 1186 cm−1 for the N–H bond, which, if calcined, disappear in the absorption spectrum.
FT-IR spectrum of nanocomposite SrFe12O19–SrTiO3.
4.3 Morphological analysis
Figure 8 shows the SEM image of SrFe12O19 nanoparticles that synthesized auto-combustion with fresh lemon without calcination. Figure 9 shows the same material with calcinated temperature 850°C for 2 h. According to SEM images, the SrFe12O19 nanoparticles without calcination are agglomerated but when nanoparticles calcinated at 850°C, the particle exhibited needle shape with the average particle size around 40 nm. Figure 10 shows SEM images of the SrTiO3 nanoparticle synthesis auto-combustion without calcination and Figure 11 shows SEM of SrTiO3 nanoparticle with calcinated temperature of 500°C. SEM images of the nanoparticles without calcination are agglomerated but when nanoparticles calcinated at 500°C, they found Spherical shape with the average particle size around 35 nm. Figure 12 illustrates SEM images of the synthesized SrFe12O19–SrTiO3 nanocomposite. The particles have needle and plane shapes.
SEM images of SrFe12O19 nanoparticle synthesis auto-combustion.
SEM images of SrFe12O19 nanoparticle synthesis autocombustion that calcinate at 850°C.
SEM images of SrTiO3 nanoparticle synthesis autocombustion.
SEM images of SrTiO3 nanoparticle synthesis autocombustion that calcinate at 500°C.
SEM images of nanocomposite SrFe12O19–SrTiO3 synthesis autocombustion.
4.4 EDX analysis
The EDX analysis of SrFe12O19 nanoparticles has been shown in Figure 13. The EDX of SrTiO3 nanoparticle and SrFe12O19–SrTiO3 nanocomposite is indicated in Figures 14 and 15, respectively. The spectra have verified particles without impurities and a good estimate with stoichiometric amounts of elements in nanoparticles.
EDX of SrFe12O19 calcinated at 850°C.
EDX of SrTiO3 calcinated at 500°C.
EDX of nanocomposite SrFe12O19–SrTiO3.
4.5 Magnetic properties
Magnetic properties of magnetic materials such as saturation magnetization (MS), remanence magnetization (Mr) and coercivity (Hc) are determined by the hysteresis loop. The room temperature hysteresis loop of SrFe12O19 was studied via vibration VSM instrument that was shown in Figure 16. The result indicates that the sample exhibit superparamagnetic property. The saturation magnetization of SrFe12O19 nanoparticles is 13 emu/g. The hysteresis loop of SrFe12O19 nanoparticles calcined at 850°C is shown in Figure 17. Saturation magnetization around 54 emu/g, remanence magnetization 30 emu/gand, and coercivity about 5000 Oe have been achieved. These amounts were confirmed as calcination of both magnetization and coercivity were increased as shown in the hysteresis loop of a ferromagnetic after calcination. Figure 18 shows the magnetic property of the SrFe12O19– SrTiO3 nanocomposite. Saturation magnetization, remanence magnetization and coercivity about 20 emu/g, 12 emu/g and 4500 Oe were obtained respectively. The magnetic properties of the SrFe12O19–SrTiO3 nanocomposites were affected by the magnetic exchange interactions between the different phases of these nanocomponents. It is clear that the nanocomposite is classified as a hard magnetic material. The magnetization and coercivity are decreased in the composite because of the SrTiO3 phase.
VSM of SrFe12O19 at room temperature.
VSM of nanoparticle SrFe12O19 calcinated at 850°C.
VSM of nanocomposite SrFe12O19–SrTiO3.
4.6 Photocatalytic properties
The photocatalytic properties of the SrFe12O19–SrTiO3 nanocomposite were checked via degradation of four azo dyes in the form of an aqueous solution, under irradiation of UV light (Hedayati et al., 2016; Kiani et al., 2019; Nabiyouni and Ghanbari, 2018; Sabet et al., 2014; Salavati-Niasari et al., 2009). The UV-Vis absorption spectra of (a) acid black, (b) acid brown, (c) methyl red, and (d) methyl orange azo dyes in the presence of SrFe12O19–SrTiO3 nanocomposite were shown in Figure 19.
UV-Vis absorption spectra of (a) acid black, (b) acid brown, (c) methyl red, and (d) methyl orange in the presence of nanocomposite SrFe12O19–SrTiO3 photocatalyst.
In order to carry out this photocatalytic procedure, 0.5 g of synthesized SrFe12O19–SrTiO3 nanocomposite were placed each in 50 mL solutions of 4 above colored dyes under microwave conditions and laboratory UV light. With passing time, more and more dyes concentration were adsorbed via the nanoparticles catalyst until the absorption peaks (kmax) of acid black, acid brown, methyl red and methyl orange decreased and vanished approximately after 60 min. As shown in Figure 20, black acid in 30 min about 95%, brown acid in 40 min about 97%, methyl red in 40 min around 98% and methyl orange in 60 min about 95% were degraded. These results indicate good photocatalytic strength of the synthesized nanocomposite. Finally, the magnetic nanocomposite powder can also be extracted by the magnet and removed from the solution. Then, by centrifugation and rinsing it with deionized double distilled water, it is ready for reuse in the next dye. The mechanism of photo-degradation of toxic azo-dyes under ultraviolet irradiation photocatalytic nanocomposite SrFe12O19–SrTiO3 with an indirect bandgap about 3.2 eV is depicted in Figure 21. As it was shown before, organic dyes decompose to CO2, H2O, and other less toxic or nontoxic remaining materials (Gillani et al., 2020; Hasegawa et al., 2000; Piskunov et al., 2004). Tabel 2 shows some related published works about photocatalytic properties.
Photo-degradation of (a) acid black, (b) acid brown, (c) methyl red, and (d) methyl orange in the presence of nanocomposite SrFe12O19–SrTiO3.
Photo-catalyst mechanism of SrFe12O19–SrTiO3 in the case of degradation of toxic dye.
Related published works about photocatalytic properties.
| Nonoparticles | Methods | Average crystalline size | Photo activity of nano-photo-catalyst | |||
|---|---|---|---|---|---|---|
| acid black | 30 min | 95% | ||||
| Our results | SrFe12O19– | Auto-combustion | 50 nm | acid brown | 40 min | 97% |
| SrTiO3 | methyl red | 40 min | 98% | |||
| methyl orange | 60 min | 95% | ||||
| acid black | 80 min | |||||
| (Hedayat et al., 2016) | CoFe2O4–CdS | precipitation | 90 nm | acid brown | 100 min | |
| acid blue | 120 min | |||||
| (Mehdizadeh etal., 2020) | LaFeO3 | sonochemical | 67 nm | degrades erythrosine under visible light | 90 min | 53% |
| degrades of erythrosine under UV light | 90 min | 93.5% | ||||
| destruction of eriochrome black T | 89.61% | |||||
| (Monsef et al., 2020) | PrVO4 | sonochemical | 25 nm | decoloration of erythrosine | 27.92% | |
| methyl violet | 8.48% | |||||
| ( Ahmadi Golsefidi et al., 2016) | Fe2O3–TiO2 | sonochemical | 60 nm | methylene blue | 81% | |
5 Conclusion
In this study, SrFe12O19–SrTiO3 nanocomposite was prepared using a green synthesis by auto-combustion sol-gel method using lemon juice extracts. The XRD pattern of the SrFe12O19 and SrTiO3 nanoparticles and SrFe12O19–SrTiO3 nanocomposite have shown a pattern of pure hexaferrite strontium and perovskite strontium phase. The nanocrystalline size and the strain of the network of all particles have been calculated using the Debye-Scherrer and Williamson-Hall method. The FTIR spectrum of the SrFe12O19 nanoparticles shows the Fe–O and Sr–O band peaks. FTIR spectrum of SrTiO3 nanoparticles indicates the band of Ti–O and Sr–O peaks. Also, in the
FTIR spectrum of the SrFe12O19–SrTiO3 nanocomposite all peaks of SrFe12O19 and SrTiO3 nanoparticles were observed. SEM images of SrFe12O19 and SrTiO3 nanoparticles have shown calcination caused reduce agglomeration of particles. Also, all images have an average size under 100 nm and the grain sizes are well estimated with crystallite sizes calculated by XRD patterns. The EDX analysis of nanoparticles and nanocomposites show particles without impurities and with a good estimate, stoichiometric amount of elements in nanoparticles. The hysteresis loop of SrFe12O19 shows that nanoparticles without calcination is superparamagnetic and calcined at 850°C is ferromagnetic. Also, hysteresis loops of SrFe12O19 confirmed by calcined as both magnetization and coercivity were increased. Magnetic studies of SrFe12O19–SrTiO3 nanocomposite indicate magnetization and coercivity have decreased in the composite because of the SrTiO3 shell. The photocatalytic properties of the SrFe12O19–SrTiO3 nanocomposite were investigated under irradiation of UV light. SrFe12O19–SrTiO3 nanocomposite degraded more than 90% of black acid, brown acid, methyl red, and methyl orange in less than 60 min. While the simplicity of this photocatalyst synthesis is one of its possible advantages, it is time-consuming that this can be its disadvantage.The results denoted that SrFe12O19– SrTiO3 nanocomposite has the potential to be applied for improving and removing organic and toxic water pollutants.
References
Ahmadian-Fard-Fini S., Ghanbari D., Amiri O., Salavati-Niasari, M., Electro-spinning of cellulose acetate nanofibers/Fe/carbon dot as photoluminescence sensor for mercury (II) and lead (II) ions. Carbohyd. Polym., 2020, 229, 115428.10.1016/j.carbpol.2019.115428Search in Google Scholar PubMed
Ahmadian-Fard-Fini S., Salavati-Niasari M., Ghanbari D., Hydrothermal green synthesis of magnetic Fe3O4-carbon dots by lemon and grape fruit extracts and as a photoluminescence sensor for detecting of E. coli bacteria. Spectrochim. Acta A, 2018, 203, 481-493.10.1016/j.saa.2018.06.021Search in Google Scholar PubMed
Ahmadi Golsefidi M., Abbasi F., Abrodi M., Abbasi Z., Yazarlou F., Synthesis, characterization and photocatalytic activity of Fe2O3-TiO2 nanoparticles and nanocomposites. J. Nanostruct., 2016, 6(1), 64-69.Search in Google Scholar
Almessiere M.A., Slimani Y., Güngüneş H., El Sayed H.S., Baykal A., AC susceptibility and Mossbauer study of Ce3+ ion substituted SrFe12O19 nanohexaferrites. Ceram. Int., 2018, 44(9), 10470-10477.10.1016/j.ceramint.2018.03.064Search in Google Scholar
Ariaee S., Mehdipour M., Moradnia M., Spectroscopy of peaks at microwave range for nanostructure SrFe12O19 and NiFe2O4 ferrite particles. J. Magn. Magn. Mater., 2017, 429, 348-352.10.1016/j.jmmm.2017.01.030Search in Google Scholar
Auwal I. A., Erdemi H., Sözeri H., Güngüneş H., Baykal A., Magnetic and dielectric properties of Bi3+ substituted SrFe12O19 hexaferrite. J. Magn. Magn. Mater., 2016, 412, 69-82.10.1016/j.jmmm.2016.03.066Search in Google Scholar
Davar F., Salavati-Niasari M., Mir N., Saberyan K., Monemzadeh M., Ahmadi E., Thermal decomposition route for synthesis of Mn3O4 nanoparticles in presence of a novel precursor. Polyhedron, 2010, 29(7), 1747-1753.10.1016/j.poly.2010.02.026Search in Google Scholar
Deganello F., Marcì G., Deganello G., Citrate–nitrate auto-combustion synthesis of perovskite-type nanopowders: A systematic approach. J. Eur. Ceram. Soc., 2009, 29(3), 439-450.10.1016/j.jeurceramsoc.2008.06.012Search in Google Scholar
Dong S., Feng J., Fan M., Pi Y., Hu L., Han X., et al., Recent developments in heterogeneous photocatalytic water treatment using visible light-responsive photocatalysts: a review. RSC Adv., 2015, 19, 14610-14630.10.1039/C4RA13734ESearch in Google Scholar
Eskandari N., Nabiyouni G., Masoumi S., Ghanbari D., Preparation of a new magnetic and photo-catalyst CoFe2O4–SrTiO3 perovskite nanocomposite for photo-degradation of toxic dyes under short time visible irradiation. Compos. Part B-Eng., 2019, 176, 107343.10.1016/j.compositesb.2019.107343Search in Google Scholar
Fang J., Wang J., Gan L.M., Ng S.C., Ding J., Liu X., Fine Strontium Ferrite Powders from an Ethanol-Based Microemulsion. J. Am. Ceram. Soc., 2000, 83(5), 1049-1055.10.1111/j.1151-2916.2000.tb01329.xSearch in Google Scholar
Garcıa-Cerda L.A., Rodrıguez-Fernandez O.S., Resendiz-Hernandez P.J., Study of SrFe12O19 synthesized by the sol–gel method. J. Alloy. Compd., 2004, 369(1-2), 182-184.10.1016/j.jallcom.2003.09.099Search in Google Scholar
Gaya U.I., Abdullah A.H., Heterogeneous photocatalytic degradation of organic contaminants over titanium dioxide: a review of fundamentals, progress and problems. J. Photoch. Photobio. C, 2008, 9 (1), 1-12.10.1016/j.jphotochemrev.2007.12.003Search in Google Scholar
Gillani S.S., Riaz A., Rizwan M., Shakil M., Rafique M., Murtaza G., et al., First-principles investigation of structural, electronic, optical and thermal properties of Zinc doped SrTiO3 Optik, 2020, 201, 163481.10.1016/j.ijleo.2019.163481Search in Google Scholar
Hasegawa T., Shirai M., Tanaka K., Localizing nature of photo-excited states in SrTiO3 J. Lumin., 2000, 87, 1217-1219.10.1016/S0022-2313(99)00520-7Search in Google Scholar
Hedayati K., Azarakhsh S., Saffari J., Ghanbari D., Photo catalyst CoFe2O4–CdS nanocomposites for degradationof toxic dyes: investigation of coercivity and magnetization. J. Mater. Sci.-Mater. El., 2016, 27, 8758-8770.10.1007/s10854-016-4900-zSearch in Google Scholar
Hedayati K., Behesht-Ara Z., Ghanbari D., Preparation and characterization of various morphologies of SrFe12O19 nano-structures: investigation of magnetization and coercivity. J. Mater. Sci.-Mater. El., 2017a, 28(1), 1-9.10.1007/s10854-016-5486-1Search in Google Scholar
Hedayati K., Kord M., Goodarzi M., Ghanbari D., Gharigh S., Photo-catalyst and magnetic nanocomposites: hydrothermal preparation of core–shell Fe3O4@PbS for photo-degradation of toxic dyes. J. Mater. Sci.-Mater. El., 2017b, 28, 1577-1589.10.1007/s10854-016-5698-4Search in Google Scholar
Hua Z., Cao Z., Deng Y., Jiang Y., Yang S., Sol–gel autocombustion synthesis of Co–Ni alloy powder. Mater. Chem. Phys., 2011, 126(3), 542-545.10.1016/j.matchemphys.2011.01.033Search in Google Scholar
Jacobo S.E., Bercoff P.G., Coercivity enhancement of hexagonal ferrites. Sol. State Phenom., 2013, 202, 113-125.10.4028/www.scientific.net/SSP.202.113Search in Google Scholar
Khorsand Zak A., Abd. Majid W.H., Abrishami M.E., Yousefi R., X-ray analysis of ZnO nanoparticles by Williamsone-Hall and sizeestrain plot methods. Solid State Sci., 2011, 13(1), 251-256.10.1016/j.solidstatesciences.2010.11.024Search in Google Scholar
Kiani A., Nabiyouni G., Masoumi S., Ghanbari D., A novel magnetic MgFe2O4–MgTiO3 perovskite nanocomposite: Rapid photo-degradation of toxic dyes under visible irradiation. Compos. Part B-Eng., 2019, 175, 107080.10.1016/j.compositesb.2019.107080Search in Google Scholar
Lahijani B., Hedayati K., Goodarzi M., Magnetic PbFe12O19–TiO2 nanocomposites and their photocatalytic performance in the removal of toxic pollutants. Main Group Met. Chem., 2018, 41(3-4), 53-62.10.1515/mgmc-2017-0055Search in Google Scholar
Madhavi V., Prasad T.N.V.K.V., Reddy A.V.B., Reddy B.R., Madhavi G., Application of phytogenic zerovalent iron nanoparticles in the adsorption of hexavalent chromium Spectrochim. Acta A-M., 2013, 116, 17-25.10.1016/j.saa.2013.06.045Search in Google Scholar PubMed
Mali A., Ataie A., Influence of the metal nitrates to citric acid molar ratio on the combustion process and phase constitution of barium hexaferrite particles prepared by sol–gel combustion method. Ceram. Int., 2004, 30(7), 1979-1983.10.1016/j.ceramint.2003.12.178Search in Google Scholar
Mehdizadeh P., Amiri O., Rashki S., Salavati-Niasari M., Salimian M., Foong L.K., Effective removal of organic pollution by using sonochemical prepared LaFeO3 perovskite under visible light. Ultrason. Sonochem., 2020, 61, 104848.10.1016/j.ultsonch.2019.104848Search in Google Scholar PubMed
Meng X., Xu S., Zhou J., Tang Q., Monodisperse hexagonal SrFe12O19 nanoflake with enchanced magnetic properties. Ceram. Int., 2016, 42(5), 6025-6032.10.1016/j.ceramint.2015.12.156Search in Google Scholar
Mir N., Salavati-Niasari M., Davar F., Preparation of ZnO nanoflowers and Zn glycerolate nanoplates using inorganic precursors via a convenient rout and application in dye sensitized solar cells. Chem. Eng. J., 2012, 181, 779-789.10.1016/j.cej.2011.11.085Search in Google Scholar
Mohandes F., Davar F., Salavati-Niasari M., Magnesium oxide nanocrystals via thermal decomposition of magnesium oxalate. J. Physi. Chem. Solids, 2010, 71(12), 1623-1628.10.1016/j.jpcs.2010.08.014Search in Google Scholar
Mohandes F., Salavati-Niasari M., Freeze-drying synthesis, characterization and in vitro bioactivity of chitosan/graphene oxide/ hydroxyapatite nanocomposite. RDC Adv., 2014, 4(49), 25993-26001.10.1039/c4ra03534hSearch in Google Scholar
Monsef R., Ghiyasiyan-Arani M., Amiri O., Salavati-Niasari M., Sonochemical synthesis, characterization and application of PrVO4 nanostructures as an effective photocatalyst for discoloration of organic dye contaminants in wastewater. Ultrason. Sonochem., 2020, 61, 104822.10.1016/j.ultsonch.2019.104822Search in Google Scholar PubMed
Mousavi-Kamazani M., Zarghami Z., Salavati-Niasari M., Facile and novel chemical synthesis characterization and formation mechanism of copper sulfide (Cu2S, Cu2S/CuS, CuS) nanostructures for increasing the efficiency of solar cells. J. Phys. Chem. C, 2016, 120(4), 2096-2108.10.1021/acs.jpcc.5b11566Search in Google Scholar
Nabiyouni G., Ghanbari D., Simple preparation of magnetic, antibacterial and photo-catalyst NiFe2O4@TiO2/Pt nanocomposites. J. Nanostruct., 2018, 8(4), 408-416.Search in Google Scholar
Nadagouda M.N., Castle A.B., Murdock R.C., Hussain S.M., Varma R.S., In vitro biocompatibility of nanoscale zerovalent iron particles (NZVI) synthesized using tea polyphenols. Green Chem., 2010, 12(1), 114-122.10.1039/B921203PSearch in Google Scholar
Palomino R.L., Miró A.B., Tenorio F.N., De Jesús F.S., Escobedo C.C., Ammar S., Sonochemical assisted synthesis of SrFe12O19 nanoparticles. Ultrason. Sonochem., 2016, 29, 470-475.10.1016/j.ultsonch.2015.10.023Search in Google Scholar PubMed
Piskunov S., Heifets E., Eglitis R.I., Borstel G., Bulk properties and electronic structure of SrTiO3 BaTiO3 PbTiO3 perovskites: an ab initio HF/DFT study. Comp. Mater. Sci., 2004, 29(2), 165-178.10.1016/j.commatsci.2003.08.036Search in Google Scholar
Sabet M., Salavati-Niasari M., Amiri O., Using different chemical methods for deposition of CdS on TiO2 surface and investigation of their influences on the dye-sensitized solar cell performance. Electrochim. Acta, 2014, 117, 504-520.10.1016/j.electacta.2013.11.176Search in Google Scholar
Safardoust-Hojaghan H., Salavati-Niasari M., Degradation of methylene blue as a pollutant with N-doped graphene quantum dot/titanium dioxide nanocomposite. J. Clean. Prod., 2017, 148, 31-36.10.1016/j.jclepro.2017.01.169Search in Google Scholar
Salavati-Niasari M., Ship-in-a-bottle synthesis, characterization and catalytic oxidation of styrene by host (nanopores of zeolite-Y)/ guest ([bis (2-hydroxyanil) acetylacetonato manganese (III)]) nanocomposite materials (HGNM). Micropor. Mesopor. Mat., 2006, 95(1-3), 248-256.10.1016/j.micromeso.2006.05.025Search in Google Scholar
Salavati-Niasari M., Amiri A., Synthesis and characterization of alumina-supported Mn (II), Co (II), Ni (II) and Cu (II) complexes of bis (salicylaldiminato) hydrazone as catalysts for oxidation of cyclohexene with tert-buthylhydroperoxide. Appl. Catal. A-Gen., 2005, 290, 1-2, 46-53.10.1016/j.apcata.2005.05.009Search in Google Scholar
Salavati-Niasari M., Davar F., In situ one-pot template synthesis (IOPTS) and characterization of copper (II) complexes of 14-membered hexaaza macrocyclic ligand “3, 10-dialkyldibenzo-1, 3, 5, 8, 10, 12-hexaazacyclotetradecane. Inorg. Chem. Commun., 2006, 9(2), 175-179.10.1016/j.inoche.2005.10.028Search in Google Scholar
Salavati-Niasari M., Davar F., Loghman-Estarki M.R., Controllable synthesis of thioglycolic acid capped ZnS (Pn) 0.5 nanotubes via simple aqueous solution route at low temperatures and conversion to wurtzite ZnS nanorods via thermal decompose of precursor. J. Alloy. Compd., 2010, 494(1-2), 199-204.10.1016/j.jallcom.2009.10.265Search in Google Scholar
Salavati-Niasari M., Farhadi-Khouzani M., Davar F., Bright blue pigment CoAl2O4 nanocrystals prepared by modified sol–gel method. J. Sol-Gel Sci. Tech., 2009, 52(3), 321-327.10.1007/s10971-009-2050-ySearch in Google Scholar
Salavati-Niasari M., Nanodimensional microreactor-encapsulation of 18-membered decaaza macrocycle copper (II) complexes. Chem. Lett., 2005a, 34(2), 244-245.10.1246/cl.2005.244Search in Google Scholar
Salavati-Niasari M., Nanoscale microreactor-encapsulation 14-membered nickel (II) hexamethyl tetraaza: synthesis, characterization and catalytic activity. J. Mol. Catal. A-Chem., 2005b, 229(1-2), 159-164.10.1016/j.molcata.2004.11.016Search in Google Scholar
Salavati-Niasari M., Zeolite-encapsulation copper (II) complexes with 14-membered hexaaza macrocycles: synthesis, characterization and catalytic activity. J. Mol. Catal. A-Chem., 2004, 217(1-2), 87-92.10.1016/j.molcata.2004.02.022Search in Google Scholar
Shabanian M., Basaki N., Khonakdar H.A., Jafari S.H., Hedayati K., Wagenknecht U., Novel nanocomposites consisting of a semi-crystalline polyamide and Mg–Al LDH: Morphology, thermal properties and flame retardancy. Appl. Clay Sci., 2014, 90, 101-108.10.1016/j.clay.2013.12.033Search in Google Scholar
Thornton G., Tofield B.C., Williams D.E., Spin state equilibria and the semiconductor to metal transition of LaCoO3 Solid State Commun., 1982, 44(8), 1213-1216.10.1016/0038-1098(82)91088-2Search in Google Scholar
Valenzuela R., Novel applications of ferrites. Phys. Res. Int., 2012, 44(38).10.1155/2012/591839Search in Google Scholar
Wang Y., Li Q., Zhang C., Li B., Effect of Fe/Sr mole ratios on the formation and magnetic properties of SrFe12O19 microtubules prepared by sol–gel method. J. Magn. Magn. Mater., 2009a, 321(19), 3368-3372.10.1016/j.jmmm.2009.05.066Search in Google Scholar
Wang Y., Li Q., Zhang C., Jing H., Preparation and magnetic properties of different morphology nano-SrFe12O19 particles prepared by sol–gel method. J. Alloy. Compd., 2009b, 467(1-2), 284-28710.1016/j.jallcom.2007.12.037Search in Google Scholar
Wohlfarth E.P., Buschow K.H.J., Ferromagnetic Materials: A Handbook on the properties of Magnetically Ordered Substances (Chapter 5). North-Holland, 1982, 305-391.Search in Google Scholar
Xia A., Zuo C., Chen L., Jin C., Lv Y., Hexagonal SrFe12O19 ferrites: hydrothermal synthesis and their sintering properties. J. Magn. Magn. Mater., 2013, 332, 186-191.10.1016/j.jmmm.2012.12.035Search in Google Scholar
Yang X., Li Q., Zhao J., Li B., Wang Y., Preparation and magnetic properties of controllable-morphologies nano-SrFe12O19 particles prepared by sol–gel self-propagation synthesis. J. Alloy. Compd., 2009, 475(1-2), 312-315.10.1016/j.jallcom.2008.08.019Search in Google Scholar
Yousefi M., Gholamian F., Ghanbari D., Salavati-Niasari M., Polymeric nanocomposite materials: preparation and characterization of star-shaped PbS nanocrystals and their influence on the thermal stability of acrylonitrile–butadiene–styrene (ABS) copolymer. Polyhedron, 2011, 30(6), 1055-1060.10.1016/j.poly.2011.01.012Search in Google Scholar
Zhu F., Ma S., Liu T., Deng X., Green synthesis of nano zero-valent iron/Cu by green tea to remove hexavalent chromium from groundwater. J. Clean. Prod., 2018, 174, 184-190.10.1016/j.jclepro.2017.10.302Search in Google Scholar
Zinatloo-Ajabshir S., Salavati-Niasari M., Nanocrystalline Pr6O11 synthesis, characterization, optical and photocatalytic properties. New J. Chem., 2015, 39(5), 3948-3955.10.1039/C4NJ02106ASearch in Google Scholar
© 2020 Karahroudi et al., published by De Gruyter
This work is licensed under the Creative Commons Attribution 4.0 International License.
