Magnetically separable nanocomposites based on ZnO and their applications in photocatalytic processes: A review

The purpose of this research is to prepare novel, inexpensive, eco‐friendly and efficient magnetic nanocomposites for degradation of pollutant from wastewater and their potential antibacterial activity. To reach this goal, we have synthesized magnetic MnFe2O4@SiO2@Au (MnFe@Si@Au) nanocomposites through ultrasound assisted co‐precipitation technique in presence of carbohydrate and Crataegus fruits extract, for the first time. The influence of capping agents including sucrose, glucose, PVA and reducing agents such as C. microphylla and C. pentagyna on the morphology, size, purity, photocatalytic and antibacterial behavior of magnetic nanocomposites were investigated. The FT‐IR, XRD, VSM, EDS, FE‐SEM, TEM and BET analysis were performed to confirm the formation of magnetic nanocomposites. MnFe@Si@Au nanocomposites have shown promising potential in degradation of organic contaminants including rhodamine b (RhB), 2‐naphthol (2‐NPH), methyl violet (MV), erythrosine (ER) and eriochrome black T (EBT) under both radiation conditions. The results show that degradation of the anionic contaminants is more than cationic contaminants under UV and visible irradiations. As well as, these synthesized spherical MnFe@Si@Au nanocomposites show excellent antibacterial activities against P. aeruginosa, K. pneumoniae and P. mirabilis bacteria. In addition to the features mentioned, another prominent feature of this nanocatalyst is retaining their photocatalytic activity after five cycles of utilization.

Section: Introductionmentioning

confidence: 99%

Facile and eco‐benign synthesis of a novel MnFe₂O₄@SiO₂@Au magnetic nanocomposite with antibacterial properties and enhanced photocatalytic activity under UV and visible‐light irradiations

Shirzadi‐Ahodashti

Ebrahimzadeh

Ghoreishi

et al. 2020

“…In the nanoparticles, however, the band gap increases due to quantum confinement. With sufficient energy separation between the valence and conduction bands, the transference of holes and electrons onto adsorbates becomes feasible . This indicates the start of photocatalysis process …”

Section: Introductionmentioning

confidence: 99%

Investigation of photocatalytic chlorpyrifos degradation by a new silica mesoporous material immobilized by WS₂ and Fe₃O₄ nanoparticles: Application of response surface methodology

Merci

Saljooqi

Shamspur

et al. 2020

In the present research, Fe3O4 and WS2 nanoparticles immobilized on or in KIT‐6 (KIT: Korea Institute of Science and Technology) pores (KIT‐6/WS2‐Fe3O4) were synthesized and studied as a photocatalyst for degradation of representative chlorpyrifos as an organophosphorus pesticide. In addition, the KIT‐6/WS2‐Fe3O4 photocatalyst was characterized by different methods such as TEM, FESEM‐EDS‐Mapping, XRD, and N2 adsorption/desorption surface area, in order to understand their morphology, structural, and physical properties. The photocatalytic performance of this photocatalyst was investigated for degradation of chlorpyrifos by visible light irritation. The effects of variables such as chlorpyrifos concentration, KIT‐6/WS2‐Fe3O4 nanocatalyst amount, pH, and irradiation time on chlorpyrifos degradation efficiency was studied by central composite design with response surface methodology. The optimum conditions for CP degradation were obtained by 50 mg KIT‐6/WS2‐Fe3O4 nanocatalyst, and 7.2 ppm chlorpyrifos solution with pH = 6, at 52 min. The pseudo‐first‐order model with rate constants equal to 0.069 min−1 as best choice efficiency described the chlorpyrifos degradation process according to Langmuir‐Hinshelwood kinetic.

“…Recently, secondary pollution of photocatalysts in practical applications has aroused people's widespread attention to the recyclability of photocatalysts. To overcome these challenges, magnetical separable ferrites are very effective and critical to solve the problems of recycling and secondary pollution …”

Section: Introductionmentioning

confidence: 99%

“…To overcome these challenges, magnetical separable ferrites are very effective and critical to solve the problems of recycling and secondary pollution. [9][10][11] Among various ferrites, zinc ferrite (ZnFe 2 O 4 ) shows great advantages in photocatalyst due to its excellent chemical and physical properties, such as narrow band gap (about 1.9 eV) and excellent photochemical stability. [9,12] In addition, as a kind of soft magnetic material with excellent performance, ZnFe 2 O 4 can be well separated by using magnets.…”

Section: Introductionmentioning

confidence: 99%

Magnetic retrievable Ag/AgBr/ZnFe₂O₄ photocatalyst for efficient removal of organic pollutant under visible light

Liu

Xue

et al. 2020

In the present work, a visible‐light‐driven Ag/AgBr/ZnFe2O4 photocatalyst has been successfully synthesized via a deposition–precipitation and photoreduction method. The crystal structure, chemical composition, morphology and optical properties of the as‐prepared nanocomposites were characterized by X‐ray diffraction spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, high‐resolution transmission electron microscopy, energy‐dispersive X‐ray spectroscope, UV–vis diffuse reflectance spectroscopy and photoluminescence. The photocatalytic activities of the Ag/AgBr/ZnFe2O4 nanocomposites were evaluated through the photodegradation of gaseous toluene and methyl orange (MO) under visible light. The results revealed that the as‐prepared Ag/AgBr/ZnFe2O4 nanocomposite exhibited excellent photocatalytic activity. The degrading efficiency of MO could still reach 90% after four cycles, and the Ag/AgBr/ZnFe2O4 nanocomposite could be recycled easily by a magnet. Additionally, the enhanced photocatalytic mechanism was discussed according to the trapping experiments, which indicated that the photo‐generated holes (h+) and •O2− played important roles in photodegradation process. At last, a possible photocatalytic oxidation pathways of toluene was proposed based on the results of GC–MS. The Ag/AgBr/ZnFe2O4 composites showed potential application for efficient removal of organic pollutant.