photo-Fenton Catalytic Activity Research Articles

Pd octahedra nanocubes mediated photo-fenton catalytic performance for sustainable degradation of methylene blue

This research utilized a typical solvothermal approach, by employing Na2PdCl4 as the synthetic precursor, L-ascorbic acid (AA) as the reductant agent, and polyvinylpyrrolidone (PVP) as the practical surfactant, palladium (Pd) octahedra was finally effectively synthesized by the hydrothermal and solvothermal methods. Subsequently, characterizations of Pd octahedra were conducted by using TEM, XPS, XRD, and other analytical methods. Whereafter, Pd octahedra displayed a consistent shape and size, featuring a distinctive tip-shaped structure, which conferred upon them outstanding optical absorption properties within the near-infrared (NIR) region. Consequently, under NIR laser exposure, Pd octahedra could elevate local reaction temperature via in-situ photothermal conversion, thereby stimulating the formation of active sites of Fenton catalysts. The Photo-Fenton catalytic activity of Pd octahedra was investigated by using methylene blue (MB) as a model pollutant. The degradation efficiency of MB reached 94.8 % within 35 min under 808 nm laser irradiation, and the removal rate of MB by Pd octahedra could still reach more than 90 % after five cycles of use. All the results manifest that Pd octahedra exhibit excellent purification performance for MB dyestuff wastewater.

Efficient degradation of MCPA in water by light/MIL-88A/H2O2 system: Mechanism, degradation pathways and toxicity assessment

2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a herbicide that poses a threat to the environment. In this study, MIL-88A was utilized as a photocatalyst to degrade MCPA. Results demonstrated that the Light/MIL-88A/H2O2 system exhibited remarkable photo-Fenton catalytic activity. Under optimal conditions of pH = 3.8, H2O2 concentration of 1.2 mL/L, MIL-88A dosage of 0.2 g/L and an initial MCPA solution concentration of 50 mg/L, the degradation efficiency reached its peak, achieving a 99.9 % degradation rate of MCPA within 60 min. The morphology, structure, and photocatalytic performance of MIL-88A were investigated using characterization techniques such as SEM, XRD, XPS, and UV–vis DRS. Free radical quenching experiments and ESR characterization demonstrated that the main active material in the degradation of MCPA was •OH. The possible degradation pathways of MCPA were hypothesized by combining the results of Gaussian software and LC-MS analysis. Furthermore, the toxicity of MCPA was evaluated using T.E.S.T. software and mung bean germination experiments. The results revealed that the degradation of MCPA by Light/MIL-88A/H2O2 system could achieve solution detoxification.

Insight into heterogeneous photo-Fenton degradation of naphthol by natural magnetite: Redundancy analysis and toxicity assessment

Magnetite is a ubiquitous iron mineral in nature and its iron ions are usually isomorphically substituted by Ti and V cations, which shows a high ability for degradation of organic contaminants via the photo-Fenton process. However, numerous reports pay more attention to the activity of synthetic magnetite rather than natural magnetite. Here, three types of natural magnetite (HG01, HG02, and GCL01) with different Ti and V contents were investigated from the perspective of the difference in structural property, catalytic activity, H2O2 decomposition, and reactive oxygen species generation. Structural characterization exhibited that the purity of natural magnetite obeyed the order: GCL01 > HG02 > HG01. HG01 contained the highest Ti content in the form of ilmenite, followed by HG02 and GCL01. Moreover, HG01 yielded the highest photo-Fenton catalytic activity with 99.5 % of naphthol degradation and 96.0 % of H2O2 decomposition after 60 min reaction. The superior activity of HG01 was attributed to the relatively high Ti and V content as demonstrated by redundancy analysis. Mechanistic investigation implied that the Ti and V in the octahedral sites of the magnetite surface can accelerate the electron transfer from Fe(III) to Fe(II), resulting in higher Fenton activity. Besides, ilmenite in HG01 enhanced naphthol degradation because H2O2 accelerated the separation of photoelectron-holes pairs to promote O2− production. Furthermore, as revealed by gas chromatography-mass spectrometry and the toxicity of identified products predicted by the ECOSAR model, the toxicity of naphthol can effectively reduce accompanied by the harmless products generated. The high reusability, low iron ions residual in water, harmless end products, and easily recycled with magnetic separation suggest that natural magnetite has a promising application prospect for wastewater purification.

Aggregation-based growth of faceted Bi2Fe4O9 micro-cuboids with a remarkable visible light photo-Fenton catalytic activity

Faceted Bi2Fe4O9 micro-cuboids were successfully prepared by a facile hydrothermal method, exhibiting remarkable visible-light-Fenton oxidation properties towards RhB degradation.

Constructing a novel Ag2MoO4/MIL-101(Fe)/Ag composite for efficient crystal violet degradation via photo-Fenton-like process

This study presents a novel ternary Ag2MoO4/MIL-101(Fe)/Ag catalyst for efficient crystal violet (CV) degradation under visible light. Silver nanoparticles were in-situ generated on Ag2MoO4/MIL-101(Fe) through Ag2MoO4 reduction with NaBH4. Extensive characterization (XRD, FT-IR, FE-SEM, EDX, TEM, UV–Vis DRS, BET, PL spectroscopy) confirmed the catalyst's structure. The ternary composite exhibited significantly enhanced photo-Fenton catalytic activity, with reaction rates approximately 3.5 and 5 times faster than those observed with the Ag2MoO4/MIL-101(Fe) and pristine catalysts, respectively. Optimal conditions (H2O2 concentration of 50 mM, catalyst dosage of 2 g/L, pH 7, CV concentration of 25 mg/L, and temperature of 25 °C) were determined. Hydroxyl radicals dominated CV degradation, with minor contributions from electrons, holes, and superoxide radicals. The ternary composite showed excellent reusability, retaining over 92 % CV degradation efficiency after five cycles. The Ag2MoO4/MIL-101(Fe)/Ag composite demonstrates great potential for efficient and stable organic dye degradation, promising advancements in water treatment applications.

Enhanced photo-Fenton catalytic activity over Cu-doped Bi12O17-xCl2 nanotube for tetracycline degradation: Oxygen vacancies-induced mixed valent Cu

Fenton photocatalyst constructed by transition metal-doped semiconductor material seems to be a promising alternative to classic Fenton catalysts. A series of Cu-doped tubular Bi12O17Cl2 with sufficient oxygen vacancies (ov) was successfully prepared through a hydrothermal method. The formation of ov in the Bi12 crystal lattice can favor the Fenton reaction not only by serving as a reaction site and increasing the charge density in the photocatalyst but also by partially reducing the dopant Cu2+ to Cu+, which consequently enhances the H2O2 activation to a significantly higher rate. Notably, Cu-doped Bi12O17Cl2 ov with an optimal dopant proportion of 4 % exhibited a preferable Fenton catalytic rate 4.5 times higher than pure photocatalytic degradation. This work investigates the mutual promotion of oxygen vacancies and dopant ions in the Fenton reaction and provides a novel development scheme for the advanced oxidation process.

Promoting photo-fenton catalytic performance of novel NiZrO3-type perovskite: Optimization with response surface methodology

Perovskite type NiZrO3 photocatalysts were synthesized by ball-mill technique and used for tetracycline (TC) degradation. NiZrO3 milled for 6 h (NiZrO3-6h) had significant-99 % photo-Fenton catalytic activity on TC removal It was determined that the characteristic peaks of NiZrO3 with XRD, spherical shaped structures with SEM, no organic peaks in the structure with FTIR, band gap of 4.40 eV with DRS and stable colloids with zeta potential. Response surface methodology (RSM) including Box-Behnken design (BBD) was applied to examine H2O2, Fe2+ and initial TC concentration effects on degradation and it was observed that H2O2 concentration had the highest effect on TC degradation. The photocatalytic efficacy of NiZrO3 could still eliminate 78 % of initial antibiotic molecules after eight-cycle. The application potential for Photo-Fenton assisted NiZrO3-6h was also observed in the degradation of other organic pollutants such as drugs (salicylic acid, ciprofloxacin, ampicillin) and dye (methylene blue, rhodamine-b, orange-II, malachite green, crystal violet). It suggests that the mechanochemically synthesized NiZrO3-6h perovskite could be suitable for its effective use in the photo-Fenton catalytic system.

Construction of NdFeO<sub>3</sub> nanoparticles on reduced graphene oxide for an enhanced visible light assisted-Fenton degradation of organic pollutant in oily wastewater

In this study, reduced graphene oxide (rGO) incorporated on NdFeO3 (NFO/rGO) nanocomposite was successfully synthesized by using a facile hydrothermal method for photo-Fenton degradation of phenol in oily wastewater. The structural, elemental, morphological, optical property, and photo-Fenton performance of NFO/rGO nanocomposite were evaluated. From the characterizations, the prepared NFO/rGO nanocomposite showed a heterostructure between reduced graphene oxide (rGO) and NdFeO3. In addition, the prepared NFO/rGO photocatalyst has efficient charge separation compared to that of pure NFO. The photo-Fenton catalytic activity of the NFO/rGO photocatalyst was investigated by phenol degradation under visible light irradiation, with a maximum removal efficiency of 94.3 % after 90 min. In contrast to pure NFO, the introduction of rGO could suggestively enhance the photo-Fenton catalytic activity by increasing the specific surface area and narrow band gap energy. The possible reaction mechanism was also discussed.

Degradation of Crystal Violet Using Gadolinium Zirconium Oxide (Gd2Zr2O7) Nanoparticles

The demand for clean water free of pollution has become an urgent priority for humanity. Gd2Zr2O7 nanoparticles were successfully synthesized via sol–gel auto combustion as a type of pyrochlore to be used in the dye phytoremediation using a Fenton-like approach. Gd2Zr2O7 nanoparticles have been successfully prepared using a sol–gel auto-combustion strategy. The annealing process was performed in a furnace at 1100 °C for 2 h to form defect-fluorite structured Gd2Zr2O7 with space group Fm-3m. XRD analysis revealed that synthesized Gd2Zr2O7 nanoparticles were found to have crystallite sizes with lattice parameters of 28.5 nm and 10.524 + 0.02 Å, respectively. TEM micrographs showed the presence of a cubic-like structure with a size of about 17 nm. The band gap energy of the synthesized powders was found to be 3.8 eV relating to the impact of the crystallite size. The generated nanoparticles finally show a significant photo Fenton catalytic activity with an efficiency of 90% for the photocatalysis of crystal violet dye after 60 min. It was determined that the substantial absorption of Gd2Zr2O7 in the visible-light region, which was synergistically activated by both Gd3+ and Zr4+ ions, was the cause of the large surface area of the scattered microstructure and reactive OH. formation.

PES/Fe3S4@NiO self-cleaning membrane with rapid catalysis for effective emulsion separation and dye degradation

The Fenton membrane is effective in removing organic pollutants from wastewater through the synergy of Fenton catalysis and membrane separation. However, the preparation of a Fenton membrane with excellent self-cleaning performance, catalytic ability, and stability remains a key research direction. Herein, a polyethersulfone (PES)/Fe3S4@NiO membrane was obtained via a non-solvent phase inversion method. The intercalation of photo-Fenton catalytic Fe3S4@NiO into the PES membrane can not only enhance the hydrophilicity but also endow the membrane with photo-Fenton catalytic activity. The separation efficiency of the obtained membrane for multiple oil-in-water emulsions exceeded 98.8%. In addition, the membrane presented excellent self-cleaning performance and stability, the separation efficiency remained high and stable even after 10 cycles of oil-in-water emulsions. Meanwhile, the effective degradation of several organic dyes under visible light was simulated; results showed that the membrane can achieve nearly 100% degradation of methylene blue in 9 min as well as rhodamine B and methyl orange in 3 min, and this membrane maintained high degradation efficiency (>98.7%) even after 5 cycles. Therefore, the results indicate that this PES/Fe3S4@NiO membrane has excellent separation performance and photo-Fenton activity, and the proposed membrane has a potential application scope for efficient emulsion separation and speedy dye degradation.

A S-scheme heterojunction Fe-doped TiO2/SnO2 with rich oxygen vacancies for photo-Fenton degradation of Rhodamine B under visible light illumination

The photo-Fenton process serves as a highly efficient approach for removing contaminants from wastewater. In this study, we developed a Fe-doped TiO2/SnO2 heterojunction catalyst to enhance the efficiency of photo-Fenton catalytic activity under visible light. To investigate the physical properties of the catalysts, various characterization techniques were utilized, including XRD, SEM, TEM, HR-TEM, UV-VIS, PL, and XPS. The 7% mol Fe-doped TiO2/SnO2-OVs (TFS-7) heterostructure exhibited the highest rate constant of 17.03 × 10−3 min−1; 8.4 and 2.1 times higher than the individual components. This enhanced performance is mainly attributed to the rapid migration of photoinduced electrons to Fe3+ and the subsequent generation of Fe2+, which improved electron transfer capacity and facilitated the rapid production of hydroxyl radicals (•OH) through the reaction between Fe2+ and H2O2. We proposed a S-scheme mechanism for the Fe-doped TiO2/SnO2-OVs catalyst based on the analysis of reactive species trapping experiments, photoluminescence (PL) spectra, ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT). These findings offer not only a straightforward approach for synthesizing highly active photocatalysts for the degradation of RhB dye, but also a framework for the construction of heterostructure photocatalysts.

Enhancing the photo-Fenton catalytic activity of g-C3N5 under visible light through Z-scheme heterojunction with ferric iron

Enhancing the photo-Fenton catalytic activity of g-C3N5 under visible light through Z-scheme heterojunction with ferric iron

Effect of annealing temperature on phase transitions and photo-Fenton catalytic activity of CoFe2O4 nanopowder

In this work, the hydrothermal technique was used to synthesize cobalt ferrite (CFO) magnetic nanoparticles. Then, the as-prepared CFO sample was annealed at four different temperatures (600, 700, 800, and 900 °C) to study the effect of the annealing temperature on the crystallite growth, magnetic properties, phase transitions, and photo-Fenton catalytic activity of CFO powder samples. The properties of CoFe2O4 were characterized by X-ray powder diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, Brunauer–Emmet–Teller analysis, vibrating sample magnetometry, and catalytic tests. The results showed that the annealing temperature significantly affected the phase structure, crystallite size, morphology, specific surface area, magnetic properties, and catalytic activity of CFO powder samples. The calcined CFO sample had higher catalytic activity than the as-prepared CFO. At the annealing temperature of 600 °C (CFO-600), the catalytic efficiency and rate constant of this material for the degradation of methylene blue under ultraviolet A irradiation for 60 min reached 95% and 3.16 h−1, respectively, in the presence of oxalic acid as a potential oxidizing agent. We also found that a higher number of Fe3+ ions occupying octahedral sites on the CFO surface resulted in a higher activity of the CFO photo-Fenton catalyst. In particular, the CFO-600 powder with excellent magnetic properties exhibited a good recycling catalytic performance. The present material holds promise as a potential practical candidate for treating pollution caused by organic dyes and limiting secondary contaminants released during the photocatalyst process.

Photo-Fenton self-cleaning carbon fibers membrane supported with Zr-MOF@Fe2O3 for effective phosphate removal from algae-rich water

Adsorbents featuring abundant binding sites and high affinity to phosphate have been used to resolve water eutrophication. However, most of the developed adsorbents were focused on improving the adsorption ability of phosphate but ignored the effect of biofouling on the adsorption process especially used in the eutrophic water body. Herein, a novel MOF-supported carbon fibers (CFs) membrane with high regeneration and antifouling capability, was prepared by in-situ synthesis of well-dispersed MOF on CFs membrane, to remove phosphate from algae-rich water. The hybrid UiO-66-(OH)2@Fe2O3@CFs membrane exhibits a maximum adsorption capacity of 333.3 mg g−1 (pH 7.0) and excellent selectivity for phosphate sorption over coexisting ions. Moreover, the Fe2O3 nanoparticles anchored on the surface of UiO-66-(OH)2 through ‘phenol-Fe(III)’ reaction can endow the membrane with the robust photo-Fenton catalytic activity, which improves long-term reusability even under algae-rich condition. After 4 times photo-Fenton regenerations, the regeneration efficiency of the membrane could remain 92.2%, higher than that of hydraulic cleaning (52.6%). Moreover, the growth of C. pyrenoidosa was significantly reduced by 45.8% within 20 days via metabolism inhibition due to membrane-induced P-deficient conditions. Hence, the developed UiO-66-(OH)2@Fe2O3@CFs membrane holds significant prospects for large-scale application in phosphate sequestration of eutrophic water bodies.

Fe2O3/diatomite materials as efficient photo-Fenton catalysts for ciprofloxacin removal.

In this study, we used Fe2O3/diatomite material system toward ciprofloxacin (CIP) photo-Fenton removal in water under visible light (vis) excitation. The characterization of Fe2O3/diatomite catalysts was determined by X-ray diffraction patterns, Fourier-transform infrared analysis, inductively coupled plasma mass spectrometry, and scanning electron microscopy. The photo-Fenton catalytic activity of the Fe2O3/diatomite was appraised by the removal efficiency of the CIP throughout the effect of the H2O2 with various parameters such as initial pH, catalyst amount, and H2O2 amount. The results indicate that 0.2 gL-1 Fe2O3/diatomite catalysts achieved the highest performance at approximately 90.03% with a 50 μL H2O2 concentration. Furthermore, the Fe2O3/diatomite catalysts have high stability, with over 80% CIP removed after five cycles. This study is inspired to develop a potential material for photo-Fenton degradation of antibiotics in wastewater.

Insight into photo-fenton catalytic degradation of tetracycline by environmental friendly nanocomposite 1T-2H hybrid phases MoS2/Fe3O4/g-C3N4

Photogenerated charge recombination is a bottleneck in the field of photocatalysis. Polycrystalline materials may be an actual way to solve this problem. In this study, a novel 1T-2H hybrid phases MoS2/Fe3O4/g-C3N4 nanocomposite (MFG) was synthesized to improve the photo-Fenton degradation under visible light on tetracycline whose emergence in water environment had attracted great public attention. We got an insight into the photo-Fenton catalytic effect on tetracycline via detailed investigation and discussion. MFG was synthesized by calcination, hydrothermal and coprecipitation. The successful synthesis of 1T-2H hybrid phases MoS2 (HP–MoS2), as a polycrystalline material, was proved by XRD and XPS. After HNO3 treatment, the grain size of bulk g-C3N4 decreased obviously, and the photocatalytic effect was also improved. It showed stable performance and significant photo-Fenton catalytic activity when H2O2 was at low concentration. Especially, the best degradation efficiency of tetracycline had been more than 80% at 0.003M H2O2 within 30min. HCO3− had an obvious inhibition effect on the reaction compared with SO42−, Cl−, and NO3−, and a reasonable explanation was proposed that HCO3− reacts with •OH to form less reactive free radicals. Free radical quenching experiments and EPR proved that •OH and •O2− were the dominant free radicals. The LC-MS was employed to identified the intermediate products of TC. The synergistic effect of HP-MoS2 and acid-treated g-C3N4(HCN) improved the transfer efficiency of photogenerated charges and promoted the reduction of Fe3+, which accelerated the photo-Fenton reaction. Moreover, the reusability of the composite was observed up to four cycles and showed good recycling performance during the degradation of tetracycline.

Construction of novel CdS@CuS/g-C3N4 heterojunctions for efficient visible light-driven photo-Fenton degradation performance

The construction of heterojunctions is considered as an effective strategy to boost catalytic degradation activity of photo-Fenton catalyst. Herein, a series of CdS@CuS/g-C3N4 (CC-x/CN) heterojunctions have been successfully prepared by hydrothermal and cation exchange process, which have been applied for the removal of methyl orange (MO) via photo-Fenton process. The results demonstrate that the exchange of Cu2+ for Cd2+ on g-C3N4 could inhibit the aggregation of CdS@CuS and increase the light absorption range and the active sites. Under visible light illumination, CC-10/CN (molar ratio of CuS to CdS is 10%) exhibits the optimal photo-Fenton-like catalytic performance with the degradation efficiency of 96% towards MO (40 mg L−1) and the total organic carbon removal rate of 75% within 35 min illumination. The apparent reaction rate constant of CC-10/CN (0.088 min−1) is approximately 22 and 6.29 times higher than those of pure g-C3N4 and CdS@CuS (molar ratio of CuS to CdS is 10%), respectively. The enhanced photo-Fenton catalytic activity of CC-x/CN is mainly ascribed to the formation of the photo-Fenton effect between CC-10 and g-C3N4, which promotes the conversion and recycling of Cu2+ and Cu+. Meanwhile, the successful formation of the heterojunctions reduces the recombination rate of carriers. In addition, the cycling experiments demonstrate that CC-10/CN possesses favorable stability and recoverability. Overall, the well-designed CC-x/CN heterojunctions reveal desirable potential application in the effective treatment of sewage via photo-Fenton process.

Magnetically separable ZnFe2O4 grafted g-C3N4/rGO ternary nanocomposites for enhanced photo-Fenton catalytic activity under visible light

Ternary nanocomposites (TNCs) comprising layered functional materials with favorable band edge positions have been strategically employed to suppress the photogenerated carrier recombination and augment photocatalytic performance by harnessing the entire UV–visible–near infrared broadband spectrum. Utilizing the intrinsic magnetic properties of the co-catalysts, a series of easily separable and recyclable g-C3N4/rGO/ZnFe2O4 (CNGZF) TNCs were developed by modulating g-C3N4 mass fraction. The heterogeneous photo-Fenton performances of the TNCs were evaluated in the discoloration of methylene blue with/ or without H2O2 under visible light. The photocatalytic efficacy of TNCs with a mass ratio of 2:1:1 (i.e., 2-CNGZF) surpasses the individual merits of their counterparts, g-C3N4 and ZnFe2O4 by 11.08 and 2.91 times, respectively, and binary composite CNZF (g-C3N4/ZnFe2O4) by 2.34 times in dye degradation. In the presence of H2O2, the highest removal efficiencies of more than 93% (k = 0.0442 min−1) and 97% (k = 0.1922 min−1) were achieved within 60 min and 20 min under artificial visible light and solar irradiation, respectively. Controlling various operational parameters of the reaction medium, a remarkable improvement in the rate constant up to 0.229 min−1 was obtained for 15 mg of catalysts loading using an H2O2 concentration of 0.15 M at pH 7. The enhanced photocatalytic performances are corroborated by a large number of induced active sites, resulting from special dimension effects of the layered nanosheets, broadband absorption capabilities of the co-catalysts, and accelerated electron migration through the metallic counterparts. Electrochemical impedance spectroscopy measurements further confirm the lower interfacial charge transfer resistance and prolonged lifetime of electrons in the TNCs. Furthermore, the moderate magnetic properties of the co-catalysts ease the catalyst recovery process, exhibiting excellent stability and durability even after recycling up to four successive runs.

Synergistic effect of visible-light-driven FeOOH@Bi2MoO6 for removal of ciprofloxacin over a wide pH range: Efficient separation of photogenerated carriers and fast Fe(III)/Fe(II) cycling

An efficient photo-Fenton catalyst (FeOOH@Bi 2 MoO 6 ) was prepared through a solvothermal-impregnation method, which can achieve rapid degradation of ciprofloxacin (CIP) under the conditions of pH = 3.5 to pH = 10.5 and overcomes the problems of harsh pH application conditions and low H 2 O 2 utilization in Fenton. Combined with the characterization analysis and performance experiments, the catalytic mechanism of the FeOOH@Bi 2 MoO 6 -H 2 O 2 system is reasonably proposed. The photocatalytic-Fenton synergy facilitates the rapid separation of photogenerated carriers and the valence cycling of Fe(III)/Fe(II), which drives the reaction system to produce a large amount of OH, O 2 − and a small amount of h + to participate in the degradation process of CIP. • The synthesized FeOOH@Bi 2 MoO 6 composite had good stability and reusability. • CIP was degraded over a wide pH range of 3.5 to 10.5 with a small amount of H 2 O 2 . • Interfacial active sites of FeOOH and Bi 2 MoO 6 promote the rapid electron transfer. • The synergistic effects promote electron separation and Fe(III)/Fe(II) cycling. • OH, O 2 − and a small amount of h + played a crucial role in the degradation of CIP. Fabrication of FeOOH@Bi 2 MoO 6 composites was successfully carried out by the solvent thermal-impregnation method, and they were used as effective visible light-driven photo-Fenton catalysts. The catalyst can achieve effective degradation of CIP in the pH range of 3.5–10.5, which overcomes the problems of harsh pH application conditions and low H 2 O 2 utilization in Fenton. Notably, FeOOH@Bi 2 MoO 6 exhibited stronger photo-Fenton catalytic activity compared with pure FeOOH, pure Bi 2 MoO 6 and their simple physical mixtures, indicating that the interfacial active sites of FeOOH and Bi 2 MoO 6 are favorable for the rapid transfer of photogenerated electrons from Bi 2 MoO 6 to FeOOH. Combined with the characterization analysis and performance experiments, the catalytic mechanism of the FeOOH@Bi 2 MoO 6 -H 2 O 2 system is reasonably proposed. The photocatalytic-Fenton synergy facilitates the rapid separation of photogenerated carriers and the valence cycling of Fe(III)/Fe(II), which drives the reaction system to produce a large amount of OH, O 2 − and a small amount of h + to participate in the degradation process of CIP. In this study, the preparation of composite catalysts and the coupled use of photocatalytic-Fenton provided a feasible idea to overcome the problems of narrow pH application and low H 2 O 2 utilization in Fenton.

Development of magnetically recyclable nanocatalyst for enhanced Fenton and photo-Fenton degradation of MB and Cr(VI) photo-reduction

The present work reports the facile green synthesis of Fe3O4 magnetic nanoparticles (MNPs) and their Fenton and photo-Fenton catalytic activity for reduction reactions. The glucose-mediated MNPs exhibit spherical morphology with an average diameter of 6.3 ± 1.1 nm. The catalytic activity of MNPs evaluated for Fenton and the photo-Fenton reactions resulted in 92 and 93% dye degradation in just 120 and 75 min, respectively. The magnificence of this novel synthesis methodology is the higher efficiency of both processes at varied pH ranges. Different catalytic parameters like wide pH range, catalyst dose, and H2O2 concentrations have made it more effective for both processes. Besides, the reusability study showed 63.71 and 57.57% activity even after six cycles in Fenton and photo-Fenton processes, respectively. The scavenger study showed the involvement of •OHads over •OHfree in the Fenton process, where •OH was found as a prime source of dye degradation in the photo-Fenton process. Moreover, Fe3O4 MNPs successfully reduced the 80 ppm load of Cr(VI) within 25 min, which improved further to 15 min by adding a chelating agent. This Fenton and photo-Fenton magnetically reusable catalyst will indulge the development of water treatment in an eco-friendly and economical way with great potential.