Performance Of Photocatalysts Research Articles

Synergy of atom doping and defect construction in marigold-like Zn3In2S6 for improved photocatalytic hydrogen production

Atom doping and defect construction are effective strategies to enhance the performance of photocatalysts. Herein, zirconium (Zr) doping and sulfur vacancies (Vs) are introduced on marigold-like Zn3In2S6 (Zr-ZIS-Vs) by controlling the amount of sulfur precursors and ZrCl4 via a one-pot hydrothermal process. Remarkably, the optimized Zr-ZIS-Vs catalyst exhibits excellent photocatalytic activity, giving a photocatalytic hydrogen evolution rate of 9.44 mmol g−1 h−1, which is 10.73, 4.39 and 2.37 times higher than pure Zn3In2S6 (ZIS, 0.88 mmol g−1 h−1), Zn3In2S6 with sulfur vacancies alone (ZIS-Vs, 2.15 mmol g−1 h−1), and Zn3In2S6 with Zr doping alone (Zr-ZIS, 3.98 mmol g−1 h−1). The apparent quantum efficiency (AQE) of Zr-ZIS-Vs achieves 27.15 % and 4.90 % at λ = 370 and 456 nm, respectively. Experimental results and theoretical simulations reveal the behavioral mechanisms of the deletion of S atoms and the tendency of Zr to replace In, indicating that the defective and reference strategies can narrow the band gap, provide abundant active sites, enhance the effective transport and separation of photogenerated carriers, and modulate the transfer of active sites to empirical site S atoms to achieve the synergistic thermodynamic and kinetic interactions, which effectively enhances the performance of photocatalytic hydrogen production.

PVA hydrogel serve as a high-efficiency carrier to enhance the photocatalytic degradation performance of BiOBr

BiOBr is a bismuth-containing photocatalytic material that exhibits visible light activity, making it highly promising for applications in photocatalytic degradation of pollutants and ecological protection. However, its application is hinder by the powder form and small particle size. Loading a powder photocatalyst on a suitable carrier is a common way to solve this challenge. This study proposes that PVA hydrogel can be used as a highly efficient carrier to enhance the photocatalytic degradation performance of BiOBr. By adding a foaming agent, the pore structure of hydrogel was improved and the degradation performance to pollutants in wastewater was increased. The impact of various factors, including BiOBr photocatalyst loading, solution pH, recycling stability, and reactive species, on the photocatalytic degradation process were investigated. The performance of the PVA/BiOBr composite hydrogel to degrade methylene blue (MB) under simulated solar irradiation was studied. After a 120 min photocatalytic reaction, PVA/BiOBr-1.0 % composite hydrogel removed 99 % of 10 mg·L−1 MB, which was superior to pure BiOBr photocatalyst. This investigation is of significance as it provides insights into the integration of BiOBr catalysts key role of the PVA hydrogel carriers in enhancing the catalytic performance of BiOBr photocatalyst in wastewater treatment.

CAZ Composite Photocatalysts for H2 Production and Degradation under Visible Light.

g-C3N4/Ag-ZnO (CAZ) composite photocatalysts were synthesized successfully by the hydrothermal method. The photocatalytic performance of photocatalysts was assessed through experiments measuring both hydrogen (H2) production and the degradation of methylene blue (MB). The H2 production rate of 60% CAZ reached 2.450 mmol·g-1·h-1, which was 8.5 times that of g-C3N4. 25% CAZ degraded 99.14% of MB dye within 40 min, and its degradation rate constant was 12.4 times that of g-C3N4. CAZ composite photocatalysts have good synergistic properties in degradation and hydrogen production and exhibit better photocatalytic performance. A Z-scheme photocatalytic system mechanism of CAZ has been proposed for the enhanced H2 production and photocatalytic degradation rate.

Synthesis of VO‐TiO2/VC‐g‐C3N4 Heterojunction for Improving the Photocatalytic Activity by Introducing Defect Sites

AbstractDefect engineering is a proven strategy for enhancing the performance of photocatalysts. Herein, we present a new method for preparing heterojunction photocatalytic materials, VO‐TiO2/VC‐g‐C3N4, with enhanced activity. The presence of defect sites and a heterojunction structure in the catalyst gives rise to exceptional charge separation efficiency and light absorption capabilities. The synergistic effect of the heterojunction interface and activated defect sites, which act as active sites, significantly enhanced the overall photocatalytic performance of VO‐TiO2/VC‐g‐C3N4. The catalyst VO‐TiO2/VC‐g‐C3N4 exhibits superior photocatalytic activity in the NO degradation reaction: displaying 3.5‐ and 2.2 times higher degradation efficiency than VO‐TiO2 and VC‐g‐C3N4, respectively. Moreover, the nitrogen fixation performance of VO‐TiO2/VC‐g‐C3N4 is 3.8‐ and 3.1 times higher than that of VO‐TiO2 and VC‐g‐C3N4, respectively. Electron paramagnetic resonance (EPR) spectroscopy capture experiments revealed that 1O2 and ⋅ OH are the primary active species in the photocatalytic reaction. The collaboration of carbon vacancy defects, oxygen vacancy defects, and the heterojunction structure created additional active sites for VO‐TiO2/VC‐g‐C3N4. The insights gained from this study offer valuable guidance for the efficient design and synthesis of VO‐TiO2/VC‐g‐C3N4 heterojunction photocatalysts, and lay a solid foundation for further research and development of such systems for large‐scale environmental remediation.

Polyimide/Ag2WO4 Z-Scheme Heterojunction for Efficient Photocatalytic Degradation of Tetracycline.

It is of great significance to construct a Z-scheme heterojunction for improving solar light harvesting and achieving efficient separation of photogenerated carriers and then enhancement of the photocatalytic performance of semiconductor photocatalysts. Herein, the direct Z-scheme PI/Ag2WO4 heterojunction was designed and prepared according to the band edge potentials of the semiconductor. Due to the fact that the Z-scheme structure not only endowed the PI/Ag2WO4 composites with efficient separation of photogenerated electron-hole pairs but also reserved the redox ability of the valence band and conduction band of monophase catalysts, the 50% PI/Ag2WO4 heterojunction exhibited excellent photocatalytic activity, which were 2.9 and 1.5 times those of the PI and Ag2WO4 photocatalysts, respectively. The photocatalytic reaction mechanism of PI/Ag2WO4 composites was confirmed by the results of TEM, UV-vis, XPS, and EPR experiments. This work provides a feasible strategy to design high-performance photocatalysts in the field of practice purification of wastewater.

Sphere-shaped ZnO photocatalyst synthesis for enhanced degradation of the Quinolone antibiotic, Ofloxacin, under UV irradiation.

The sphere-shaped zinc oxide (ZnO) photocatalyst was synthesized by the homogeneous precipitation method, using Zn(CH3COO)2·2H2O as a zinc precursor and NH4OH as a precipitating agent. The morphology and crystal structure of the prepared ZnO sample were studied by XRD, SEM, FT-IR, XPS, zetapotential measurements, and a low-temperature nitrogen adsorption-desorption technique. The optical characteristics of ZnO were determined by UV - Vis diffuse reflectance spectroscopy. ZnO photocatalyst performance of up to 100% within 210min was observed in the photodegradation of the ofloxacin antibiotic under ultraviolet (UV) irradiation. The effect of antibiotic concentration, heavy metal ions, and water sources on the photocatalytic activity of ZnO demonstrated both the potential of its application under different conditions, and a good adaptability of this photocatalyst. The photodegradation reaction correlated well with the first-order kinetics model, with a rate constant of 0.0173min-1. The reusability of the photocatalyst was verified after three cycles of use. Admittedly, photogenerated electrons and holes played a key role in removal of the antibiotic. This work showed the suitability of prepared ZnO for antibiotic removal, and its potential use for environmental protection.

Coal-based carbon quantum dots modified Ni-MOF and Co/Zr-MOF heterojunctions for efficient photocatalytic hydrogen evolution

NS-CQDs were synthesized by a hydrothermal method using high-sulfur lignite as the carbon source. Modification of Ni-MOF and Co/Zr-MOF using NS-CQDs to explore the performance of composite photocatalysts for hydrogen production. It was found that NS-CQDs significantly enhanced the hydrogen precipitation performance of the composite photocatalysts compared with the MOFs catalysts alone, and the highest hydrogen precipitation rate of the novel composite photocatalyst 5%NS-CQDs/NCZ2 reached 3662.68 μmol g−1 h−1. It can be inferred from the conduction band and valence band positions of Ni-MOF, Co/Zr-MOF and NS-CQDs that a double S-type heterojunction is formed. The presence of thiophene and pyrrole nitrogen in NS-CQDs can promote electron transport, reduce the rate of electron-hole pair complexation, and improve the hydrogen evolution activity of the 5%NS-CQDs/NCZ2.

BiOClxM1-x (M=I, Br) solid solution-coupled CdS photocatalysts for enhancing visible light-driven organic pollutants degradation with simultaneous hydrogen production

The construction of Z-scheme heterojunction stands out as one of the most effective modification methods for enhancing the performance of photocatalysts. Therefore, BiOClxM1-x (M=I, Br) solid solution-coupled CdS (BiOClxM1-x/CdS) Z-scheme photocatalysts were successfully synthesized by a hydrothermal-precipitation method. BiOCl0.8I0.2/CdS exhibited notable photocatalytic performance with a hydrogen yield of 261 μmol/g, which was 2.23, 1.56 and 1.44 times higher than that of CdS, BiOCl/CdS and BiOCl0.5Br0.5/CdS, respectively. This improvement can be attributed to two key factors: (1) the formation of BiOClxM1-x (M=I, Br) solid solution enhances visible light absorption; (2) The formation of BiOCl0.8I0.2/CdS (M=I, Br) Z-scheme heterojunctions inhibit the recombination of photogenerated carriers to prolong the lifetime of photogenerated carriers, thus increasing the utilization of the photogenerated carriers. Moreover, BiOCl0.8I0.2/CdS also showed good photocatalytic activity in ROW-DFHP (residual organic wastewater from dark fermentation for hydrogen production), with a hydrogen production rate of 42.83 μmol/g and a mineralization rate of organic pollutants of 31.73%. Cycling experiments, XRD and SEM of the samples before and after the photocatalytic reaction showed that BiOCl0.8I0.2/CdS has good stability. Furthermore, the mechanism of BiOCl0.8I0.2/CdS for the photocatalytic degradation of organic pollutants and simultaneous hydrogen production was proposed, offering a novel strategy for organic wastewater purification and hydrogen energy recovery.

From Plastic Waste to Green Hydrogen and Valuable Chemicals Using Sunlight and Water

Over 79% of 6.3 billion tonnes of plastics produced from 1950 to 2015 have been disposed in lanfills or found their way to the oceans, where they will reside for up to hundreds of years before being decomposed bringing upon significant dangers to our health and ecosystems. Plastic photoreforming offers an appealing alternative by using solar energy and water to transform plastic waste into value‐added chemical commodities, while simultaneously producing green hydrogen via the hydrogen evolution reaction. This review aims to provide an overview of the underlying principles of emerging plastic photoreforming technologies, highlight the challenges associated with experimental protocols and performance assessments, discuss recent global breakthroughs on the photoreforming of plastics, and propose perspectives for future research. A critical assessment of current plastic photoreforming studies shows a lack of standardised conditions, hindering comparison amongst photocatalyst performance. Guidelines to establish a more accurate evaluation of materials and systems are proposed with the aim to facilitate the translation of promising fundamental discovery in photocatalysts design.

From Plastic Waste to Green Hydrogen and Valuable Chemicals Using Sunlight and Water.

Over 79% of 6.3 billion tonnes of plastics produced from 1950 to 2015 have been disposed in lanfills or found their way to the oceans, where they will reside for up to hundreds of years before being decomposed bringing upon significant dangers to our health and ecosystems. Plastic photoreforming offers an appealing alternative by using solar energy and water to transform plastic waste into value-added chemical commodities, while simultaneously producing green hydrogen via the hydrogen evolution reaction. This review aims to provide an overview of the underlying principles of emerging plastic photoreforming technologies, highlight the challenges associated with experimental protocols and performance assessments, discuss recent global breakthroughs on the photoreforming of plastics, and propose perspectives for future research. A critical assessment of current plastic photoreforming studies shows alack of standardised conditions, hindering comparison amongst photocatalyst performance. Guidelines to establish a more accurate evaluation of materials and systems are proposed with the aim to facilitate the translation of promising fundamental discovery in photocatalysts design.

Efficiency and mechanistic insights of photocatalytic decomposition of tetracycline and rhodamine B utilizing Z-scheme g-C3N4/SnWO4 heterostructures under visible light irradiation

The hydrothermal approach was used in the design and construction of the SnWO4 (SW) nanoplates anchored g-C3N4 (gCN) nanosheet heterostructures. Morphology, optical characteristics, and phase identification were investigated. The heterostructure architect construction and successful interface interaction were validated by the physicochemical characteristics. The test materials were used as a photocatalyst in the presence of visible light to break down the antibiotic tetracycline (TC) and the organic Rhodamine B (RhB). The best photocatalytic degradation efficiency of TC (97%) and RhB (98%) pollutants was demonstrated by the optimized 15 mg of gCNSW-7.5 in 72 and 48 min, respectively, at higher rate constants of 0.0409 and 0.0772 min−1. The interface contact between gCN and SW, which successfully enhanced charge transfer and restricted recombination rate in the photocatalyst, is responsible for the enhanced performance of the gCNSW heterostructure photocatalyst. In addition, the gCNSW heterostructure photocatalyst demonstrated exceptional stability and reusability over the course of four successive testing cycles, highlighting its durable and dependable function. Superoxide radicals and holes were shown to be key players in the degradation of contaminants through scavenger studies. The charge transfer mechanism in the heterostructure is identified as Z-scheme mode with the help of UV–vis DRS analysis. Attributed to its unique structural features, and effective separation of charge carriers, the Z-scheme gCNSW-7.5 heterostructure photocatalyst exhibits significant promise as an exceptionally efficient catalyst for the degradation of pollutants. This positions it as a prospective material with considerable potential across various environmental applications.

Boosting the Photocatalytic Performance of g-C3N4 through MoS2 Nanotubes with the Cavity Enhancement Effect.

The development of catalysts with high photon utilization efficiency is crucial for enhancing the catalytic performance of photocatalysts. Graphitic carbon nitride (g-C3N4) is a prominent material in the field of photocatalysis. However, it still exhibits drawbacks such as low utilization of visible light and severe recombination of photogenerated carriers. To address these issues, this study employs MoS2 nanotubes (NTs) as cocatalysts and constructs MoS2 NTs/g-C3N4. The MoS2 NTs/g-C3N4 exhibits a significant cavity enhancement effect through multiple light reflections. This results in a broad spectral absorption range and high photon utilization efficiency, while also reducing the recombination of photogenerated carriers. The photocatalyst demonstrates outstanding performance in both photocatalytic hydrogen production and photodegradation of organic pollutants. Specifically, the hydrogen production rate is 1921 μmol·g-1·h-1, which is approximately 2.4 times that of g-C3N4. Furthermore, the photodegradation rate of Rhodamine B reaches 98.6% within 30 min, which is approximately three times higher than that of g-C3N4. Free radical capture experiments confirm that holes (h+) are the primary active species in photodegradation. A plausible photocatalytic mechanism for the catalyst is proposed. This study provides valuable insights into the development of heterojunction photocatalysts with high photon utilization efficiency.

A Review of the Effect of Defect Modulation on the Photocatalytic Reduction Performance of Carbon Dioxide.

Constructive defect engineering has emerged as a prominent method for enhancing the performance of photocatalysts. The mechanisms of the influence of defect types, concentrations, and distributions on the efficiency, selectivity, and stability of CO2 reduction were revealed for this paper by analyzing the effects of different types of defects (e.g., metallic defects, non-metallic defects, and composite defects) on the performance of photocatalysts. There are three fundamental steps in defect engineering techniques to promote photocatalysis, namely, light absorption, charge transfer and separation, and surface-catalyzed reactions. Defect engineering has demonstrated significant potential in recent studies, particularly in enhancing the light-harvesting, charge separation, and adsorption properties of semiconductor photocatalysts for reducing processes like carbon dioxide reduction. Furthermore, this paper discusses the optimization method used in defect modulation strategy to offer theoretical guidance and an experimental foundation for designing and preparing efficient and stable photocatalysts.

Interlayer anions modulated ZnAl-layered double hydroxides for enhanced photocatalytic CO2 reduction

Photocatalytic CO2 reduction has drawn widespread attention across all sectors of society. Layered double hydroxides (LDHs) have emerged as promising photocatalysts, renowned for their adjustable bandgaps and reaction sites. As a typical anionic layered material, LDHs exhibit intricate interactions between interlayer anions and brucite-like metal layers, greatly influencing their inherent physicochemical properties. In this work, we synthesized ZnAl-LDH samples intercalated with four distinct anions: carbonate (CO32–), chloridion (Cl–), nitrate (NO3–), and dodecyl sulfate (DS–), denoted as LDH-CO3, LDH-Cl, LDH-NO3, and LDH-DS, respectively. These LDHs samples have comparable crystallinity and morphology but differ in their interlayer spacing. XRD results reveal interlayer spacings of 0.77 nm for LDH-CO3, 0.78 nm for LDH-Cl, 0.88 nm for LDH-NO3, and 1.24 nm for LDH-DS, between adjacent brucite-like ZnAl hydroxide layers. Remarkably, LDH-NO3 demonstrates the highest photocatalytic CO2 reduction performance, with CO as the primary reduction product. Specifically, the average CO production rate of LDH-NO3 are 3.80 μmol g–1 h–1, surpassing that of LDH-CO3, LDH-Cl, and LDH-DS by 1.9, 2.1, and 2.5 times, respectively. This superior performance can be attributed to the intermediate interlayer spacing of LDH-NO3, which facilitates strong light absorption and a robust local built-in electric field. Theses properties enhance charge generation and separation abilities, leading to efficient photocatalytic reactions. The obtained results highlight the critical role of controlling small molecules within the interlayer, alongside defects, in the design and fabrication of layered-structure photocatalysts. This study provides valuable insights into optimizing the performance of LDH-based photocatalysts for CO2 reduction and potentially other photocatalytic applications.

Sunlight removal of diclofenac using g-C3N4, g-C3N4/Cl, g-C3N4/Nb2O5 and g-C3N4/TiO2 photocatalysts

This study aimed to investigate four photocatalysts, whether element-doped (g-C3N4/Cl) or through heterojunctions (g-C3N4/Nb2O5 and g-C3N4/TiO2), and compare against unmodified (bare) g-C3N4 for diclofenac removal under artificial sunlight. The synthesis methodologies were deliberately chosen for simplicity to enable practical applications. Additionally, the potential phytotoxicity of the products was investigated. In this sense, the main novelty of the present work is to contribute to elucidate the performance of photocatalysts commonly employed in photocatalysis (such as Nb2O5 and TiO2), but combined with a material that allows them to be photoactive under visible irradiation. Under the experimental conditions of this study (C0= 20 mgL−1; Ccat. = 600 mgL−1; pH = 6.0; artificial sunlight: 40 Wm−2 UVA, 245 Wm−2 VIS), the four photocatalysts displayed no statistically significant differences in diclofenac removal over the 240-minute evaluation period. However, the specific constant rate normalized by SBET indicated that bare g-C3N4 demonstrated statistically superior efficacy in diclofenac removal. When exposed to natural sunlight, bare g-C3N4 achieved a 68-minute normalized illumination time (t30w) to remove over 67% of diclofenac. Assessing phytotoxicity involved 14 assays using the four photocatalysts and two seed types (cucumber and lettuce). With a few exceptions (g-C3N4, g-C3N4/Cl, and g-C3N4/TiO2, limited to cucumber seeds), experiments revealed non-phytotoxic byproducts after diclofenac photocatalysis, as indicated by germination indices exceeding 80%.

A novel type-II–II heterojunction for photocatalytic degradation of LEV based on the built-in electric field: carrier transfer mechanism and DFT calculation

Heterojunctions play a crucial role in improving the absorption of visible light and performance of photocatalysts for organic contaminants degradation in water. In this work, a novel type-II–II Ag2CO3/Bi2WO6 (AB) heterojunction was synthesized by hydrothermal reaction and in situ-precipitation methods. The mechanisms of charge transfer and carrier separation at the interface of heterojunctions and the influence on the photocatalytic activity were investigated. The degradation of levofloxacin (LEV) under visible light irradiation was employed to evaluate the photocatalytic performance of AB. The results showed that 85.4% LEV was degraded by AB, which was 1.38 and 1.39 times higher than that of Bi2WO6 and Ag2CO3, respectively. The work functions of the different crystal planes in the AB heterojunction, which was calculated by density functional theory, are a significant difference. The Fermi energy (Ef) of Ag2CO3 (− 6.005 eV) is lower than Bi2WO6 (− 3.659 eV), but the conduction band (CB) is higher. Therefore, using AB heterojunctions as an example, the research explored the mechanism of type-II–II which CB and Ef of one semiconductor cannot simultaneously surpass those of another material, based on the built-in electric field theory. Through this analysis, a deeper understanding of type-II heterojunctions was achieved, and providing valuable insights into the behavior of this specific heterojunction system.

Effect of CdS on microstructure and performance of ZnO composite photocatalyst

AbstractIn this study, Nd‒Dy‒ZnO and CdS‒Nd‒Dy‒ZnO photocatalysts were prepared by microwave hydrothermal method to improve the photocatalytic performance of ZnO. The microstructure and performance of samples were characterized by X‐ray diffraction, scanning electron microscopy, ultraviolet (UV)‒visible, and X‐ray photoelectron spectroscopy, and evaluated with the methylene blue. The results showed that CdS attached to the ZnO crystal surface in the form of flocculent particles, and the combination with CdS promoted the growth of ZnO crystals, while an excess of CdS was found to be detrimental to the crystallization of ZnO. When nCdS/nZnO = 0.30 mol%, composite materials achieved the optimal photocatalytic performance, which made the degradation rate of methylene blue reach 93.42% under UV irradiation for 4 h. CdS‒Nd‒Dy‒ZnO composite photocatalytic material can generate active oxygen groups such as hydroxyl and superoxide radicals simultaneously, which greatly enhances the photocatalytic efficiency of the composite material.

“Edge in-situ heterogeneous” BiOI based on defect engineering and non-noble metal deposition: Boosting visible-light photocatalytic sterilization

The inherent narrow band gap of bismuth oxyiodide (BiOI) consistently leads to the rapid recombination of photogenerated carriers, significantly constraining its practical utility. To combat this shortcoming, we devise a Bi/BiOI1−x (BB) nanosheet with edge heterostructure. It is modified by the introduction of both iodine defects and in-situ bismuth deposition through high-temperature calcination and solvothermal strategy. Notably, the in-situ deposition of bismuth enhances the visible-light absorption ability of BiOI. And the incorporation of iodine defects initiates a modification in the band position of BiOI, ultimately diminishing the electron-hole recombination rate effectively. More importantly, facilitated by the major work function of bismuth, a Schottky barrier is formed at the BB heterojunction interface, which effectively promotes the separation of photogenerated charges within BB. And the photocurrent intensity of BB is 4 times higher than that of pure BiOI. These ingenious designs result in a significant boost in the generation of reactive oxygen species (ROS) through the accumulation of electrons and holes on the surfaces of both Bi and BiOI1−x. And BB photocatalyst shows an outstanding broad-spectrum bactericidal performance. The antibacterial rates against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are 88.01% and 90.01%, respectively, which are increased by 80.6% and 83.8% compared with BiOI. Moreover, in vivo experiments provide compelling evidence for the BB photocatalyst’s potential in promoting wound healing. The healing rate after BB treatment has already reached more than 95% on the fifth day. This work offers valuable insights on enhancing the sterilization performance of photocatalysts based on the synergistic effects of defect engineering and non-noble metal deposition.

Critical review on the tetracycline degradation using photo-Fenton assisted g-C3N4-based photocatalysts: Modification strategies, reaction parameters, and degradation pathway

Over the years, the enormous use of tetracycline (TC) in pharmaceutical industries caused unwanted heap in the environment that led to the deterioration of human and ecological conditions. Therefore, the synergistic functioning of photo-Fenton and photocatalysis has been introduced which enables the regeneration of more •OH, •O2- species thereby enhancing the TC degradation performance of photocatalysts. Graphitic carbon nitride (g-C3N4) photocatalyst recently, gained massive consideration due to the suitable energy band gap, efficient preparation method, and physicochemical properties. However, due to some drawbacks, various modification strategies (doping, Z-Scheme, S-Scheme) have been adopted to perk up the degradation activity of bare g-C3N4. In the current review, we have provided insights into various modification strategies employed for g-C3N4 and reaction parameters for the effective remediation of tetracycline using photo-Fenton-assisted photocatalysis. The review further highlighted the potential of the integrated effect of g-C3N4-based photo-Fenton-assisted photocatalytic processes for achieving higher tetracycline removal efficiency followed by current challenges and future perspectives.

Photocatalytic degradation of linezolid antibiotic from aqueous solution by magnetically separable nanoheterostructure Fe3O4/ MgAl2O4/BiOBr0.5Cl0.5 synthesized Composite catalyst

The photocatalytic system has been emerging as a practical method for antibiotic removal in an aqueous medium. In this study, novel MgAl2O4/BiOBr0.5Cl0.5 heterojunction was synthesized by the decoration of different mass percentages of MgAl2O4 nanoparticles (10, 20, and 30 %) on the BiOBr0.5Cl0.5 solid solution and used for the photocatalytic degradation of linezolid antibiotic. Also, to facilitate easy separation of 10 % MgAl2O4/BiOBr0.5Cl0.5 from the solution after use, it was magnetized by Fe3O4 as 2 % Fe3O4/10 % MgAl2O4/BiOBr0.5Cl0.5. Synthesized photocatalysts were characterized by XRD, XPS, Raman, FESEM, TEM, EDX, BET-BJH, DRS, PL, Mott–Schottky, VSM, and pHpzc analyses to specify the synthesized photocatalysts and determine their chemical and physical properties. In addition, the influence of experimental parameters, including pH of the initial solution, the dosage of photocatalyst, and linezolid concentration on the performance of photocatalyst in linezolid removal, were elucidated in this study. The results showed that 10 % MgAl2O4/BiOBr0.5Cl0.5 photocatalyst was the optimal sample with a maximum removal efficiency of 95.59 % within 90 min under optimal experimental parameters (1 g/L catalyst, 10 mg/L linezolid, pH = 6.5). The kinetic studies revealed that the degradation rate of 10 % MgAl2O4/BiOBr0.5Cl0.5 photocatalyst was approximately 1.8, 2.7, 2.0, and 6.3 times faster than 20 % MgAl2O4/BiOBr0.5Cl0.5, 30 % MgAl2O4/BiOBr0.5Cl0.5, BiOBr0.5Cl0.5 photocatalyst and photolysis, respectively. Scavenger tests conducted in the same process operation revealed that h+ and •O2− play the predominant roles in linezolid photocatalytic degradation. The 2 % Fe3O4/10 % MgAl2O4/BiOBr0.5Cl0.5 photocatalyst was easily collected by magnet after each use for the next run, and its activity after five runs has reached 90 %.