Efficient Fenton-like Catalyst Research Articles

Subnano-Fe (Co, Ni) clusters anchored on halloysite nanotubes: an efficient Fenton-like catalyst for the degradation of tetracycline.

Iron-based catalysts are environmentally friendly, and iron minerals are abundant in the earth's crust, with great potential advantages for PMS-based advanced oxidation process applications. However, homogeneous Fe2+/PMS systems suffer from side reactions and are challenging to reuse. Therefore, developing catalysts with improved stability and activity is a long-term goal for practical Fe-based catalyst applications. In this study, we prepared Fe-HNTs nanoreactors by encapsulating a nitrogen-doped carbon layer with one-dimensional halloysite nanotubes (HNTs) using the molten salt-assisted method. Subsequently, Fe (Co, Ni) nanoclusters were anchored onto the nitrogen-doped carbon layer at a relatively low temperature (550℃), resulting in stable and uniform distribution of metal nanoclusters on the surface of HNTs carriers in the form of Fe-Nx coordination. The results showed that the dissolution of the molten salt and leaching of post-treated metal oxides generated numerous mesopores within the Fe-HNTs nanoreactor, leading to a specific surface area more than 10 times that of HNTs. This enhanced mass transfer capability facilitates rapid pollutant removal while exposing more active sites. Remarkably, Fe-HNTs adsorbed up to 97% of tetracycline within 60min. In the Fe-HNTs/PMS system, the predominant reactive oxygen species has been shown to be 1O2, and the added tetracycline was degraded by more than 98% within 5min. The removal of tetracycline was maintained above 96% in the presence of interfering factors such as wide pH (3-11) and inorganic anions (5mM Cl-, HCO3-, NO3-, and SO42-). The investigated mechanism suggests that efficient degradation and interference resistance of the Fe-HNTs/PMS system is attributed to the synergistic effect between the rapid adsorption of porous structure and the non-radical (1O2)-dominated degradation pathway.

Magnetic CoFe alloy@N-CNTs as fenton-like activator for the efficient abatement of imidacloprid: Kinetics, transformation mechanisms, and toxicity assessment

A magnetic bimetal-carbon nanohybrid, CoFe alloy@N-CNTs was designed to activate peroxydisulfate (PDS) for the degradation of imidacloprid (IMI). Under optimal conditions, 5 mg/L of IMI were completely removed within 6 h with a mineralization degree of 42.9 %. Moreover, a high rate of IMI removal was observed over a wide pH range and in the presence of different anions and humic acids. Stability tests conducted over five cycles and material characterizations confirmed the stability of CoFe alloy@N-CNTs. Furthermore, radical and non-radical oxidation contributed to the degradation process based on the results of quenching experiments, electron paramagnetic resonance (EPR), radical quantification and X-ray photoelectron spectroscopy (XPS). Hydroxylation was identified as the main degradation pathway through mass spectrometry observation, frontier electron densities (FEDs) theory calculations, fluorescence intensities and mineralization degree. Additionally, the predicted ecotoxicity of IMI and its intermediates towards three aquatic organisms using ECOSAR software was not harmful or low toxic, verifying the potential application of this technique from an ecological risk perspective. This study provides valuable insights for designing metal–carbon nanohybrids as efficient Fenton-like catalyst in water treatment.

Double pyramid stacked CoO nano-crystals induced by graphene at low temperatures as highly efficient Fenton-like catalysts.

Transition metal oxides are widely used as Fenton-like catalysts in the treatment of organic pollutants, but their synthesis usually requires a high temperature. Herein, an all-solid-state synthesis method controlled by graphene was used to prepare a double pyramid stacked CoO nano-crystal at a low temperature. The preparation temperature decreased by 200 °C (over 30% reduction) due to the introduction of graphene, largely reducing the reaction energy barrier. Interestingly, the corresponding degradation rate constants (kobs) of this graphene-supported pyramid CoO nano-crystals for organic molecules after their adsorption were over 2.5 and 35 times higher than that before adsorption and that of free CoO, respectively. This high catalytic efficiency is attributed to the adsorption of pollutants at the surface by supporting graphene layers, while free radicals activated by CoO can directly and rapidly contact and degrade them. These findings provide a new strategy to prepare low carbon-consuming transition metal oxides for highly efficient Fenton-like catalysts.

O-Vacancy-Rich ε-MnO2 Synthesized at Hydrophobic Interface: An Efficient Fenton-like Catalyst for Removing Ciprofloxacin from Water

The widespread use of pharmaceuticals and personal care products (PPCPs) in many fields has brought convenience to human lives but has also caused unavoidable environmental pollution issues. In particular, the resistance gene problem resulting from accumulating antibiotics that cannot be fully absorbed by biological individuals has been a concern; thus, it is urgent to find efficient technologies to boost the degradation efficiency of antibiotics in the environment. Here, an ε-MnO2 catalyst was prepared by a novel droplet-interface-drying method and utilized as a Fenton-like catalyst for efficiently degrading ciprofloxacin (CIP). The ε-MnO2 shell was formed preferentially at the gas–liquid interface and then continued to decompose into ε-MnO2 with abundant O vacancies in the air-insulated microcavity. The XPS result confirms that this particular preparation method can regulate the content of O vacancies in the material. Compared with ε-MnO2 samples obtained by the direct drying method (ε-MnO2-B), the catalytic performance of ε-MnO2 prepared by the droplet-interface-drying method (ε-MnO2-P) is significantly improved. By activating peroxymonosulfate (PMS) with the ε-MnO2-P catalyst, the CIP degradation efficiency can reach 84.1%. The detection and analysis of reactive oxygen species (ROS) in the ε-MnO2-P/PMS oxidation system confirms that ·OH, SO4·− and 1O2 are the main ROS for CIP degradation. This study highlights the creation of miniature hypoxic space to regulate the content of O vacancies in ε-MnO2, providing a new idea for the synthesis of other O-vacancy-rich materials.

Iron ore tailings as efficient Fenton-like catalysts for degradation of tetracycline

Antibiotic wastewater, especially that generated from hospital and pharmaceutical industries, is highly concentrated, hazardous and in urgent need of treatment. This work explores the possibility of directly using iron ore tailings (IOT), a typical solid waste, as a Fenton catalyst for the removal of antibiotics from water. Take tetracycline hydrochloride (TC-HCl) as the target antibiotic, the degradation laws catalyzed by IOT were studied in detail. When the dosage of IOT was 300 mg·L−1 and that of H2O2 was 1700 mg·L−1, up to 99.6% of TC-HCl was degraded within 360 min, demonstrating the excellent catalytic efficiency of IOT. As a heterogeneous catalyst, IOT showed satisfactory pH suitability and could be used in a pH range from 1.6 to 11.6. IOT also showed satisfactory cyclic stability, with the catalytic degradation rate of TC-HCl only decreasing from 99.6% to 95.1% after 10 cycles. The Fe elements endowed in IOT promote the generation of ·OH and ·O2- in the presence of H2O2, which helps to scavenge organic pollutants. The mineral composition of IOT also facilitates the catalytic process.

Cu2O/Fe3O4/UiO-66 nanocomposite as an efficient fenton-like catalyst: Performance in organic pollutant degradation and influencing factors based machinelearning

The persistent presence of organic pollutants like dyes in water environment necessitates innovative approaches for efficient degradation. In this research, we developed an advanced hybrid catalyst by combining metal oxides (Cu2O, Fe3O4) with UiO-66, serving as a heterogeneous Fenton catalyst for for efficient RB19 breakdown in water with H2O2. The control factors to the catalytic behavior were also quantified by machine learning. Experimental results show that the catalytic performance was much better than its individual components (P < 0.05 & non-zero 95% C.I). The improved catalytic efficiency was linked to the occurrence of active metal centers (Fe, Cu, and Zr), with Cu(I) from Cu2O playing a crucial role in promoting increased production of HO•. Also, UiO-66 served as a catalyst support, attracting pollutants to the reaction center, while magnetic Fe3O4 aids catalyst recovery. The optimal experimental parameters for best performance were pH at 7, catalyst loading of 1.6 g/L, H2O2 strength of 0.16 M, and reaction temperature of 25 °C. The catalyst can be magnetically separated and regenerated after five recycling times without significantly reducing catalytic activity. The reaction time and pH were ranked as the most influencing factors on catalytic efficiency via Random Forest and SHapley Additive exPlanations models. The findings show that developed catalyst is a suitable candidate to remove dyes in water by Fenton heterogeneous reaction.

Ultrafast and energy-saving microwave-assisted conversion of inert carbon nanomaterials to highly efficient Fenton-like metal-free catalysts for pollutants degradation

Carbon-driven persulfate (PDS)-based Fenton-like reactions have been widely viewed as prospective strategies to cope with the water pollution. However, high cost, harsh condition and complex modification processes are usually required to boost the catalytic activities of carbocatalysts. Herein, we proposed an ultrafast, energy-efficient, and convenient approach to convert various low-performance carbon materials into highly efficient catalysts by microwave treatment in just 1 min without any other tedious treatment. This process only requires 57 kJ/g energy input, 5 orders of magnitude lower than the traditional calcination process. The catalytic performance of microwave-treated materials could increase by more than 380 times, which is even better than those of the single-atom catalysts. Moreover, DFT calculations and QSARs analyses reveal that the negatively charged carboxyl group is not conducive to the adsorption of PDS (S2O82−) due to electrostatic repulsion, and also increases the work function of the carbocatalysts, which hinders the electron transfer process.

Regulating the charge density of Cu(I) single sites enriched on the surface of N3c Vacancies-engineered g-C3N4 for efficient Fenton-like reactions

The construction of highly accessible copper active sites with enhanced charge density is essential for the performance of Cu-based Fenton catalysts. Herein, we report the preparation of a catalyst comprising Cu(I) atoms anchored on the surface of N3c vacancies-engineered g-C3N4 (Cu/Nv-CN) and its enhanced Fenton-like performance. The surface-enrichment of single Cu(I) atoms maximizes the exposure of active sites and reduces the mass transfer limitation for short-lived hydroxyl radicals. The N3c vacancies, meanwhile, facilitate electron donation from N2c to Cu sites, greatly increasing the number of single Cu(I) sites. These two strategies synergistically enhance the hydroxyl radical production rate in the Fenton-like process and endow Cu/Nv-CN with not only excellent performance in degrading various contaminants (such as phenolic compounds, endocrine disruptors, antibiotics, and dyes), both in purified and real water samples matrixes, but also superior bactericidal properties for Escherichia coli. Compared to bulk Cu-doped g-C3N4 without N3c vacancies (CO-Cu/CN), Cu/Nv-CN shows a more than 14-fold increase in phenol degradation and an enhancement of approximately 4 log10 CFU/mL in bacterial inactivation. Our strategy of increasing the number of Cu(I) single atoms through surface enrichment and enhanced electron donation opens up a new route for the design of efficient Fenton-like catalysts for environmental remediation.

Defective iron based metal-organic frameworks derived from zero-valent iron for highly efficient fenton-like catalysis.

Introducing crystal defects into iron based metal-organic frameworks (Fe-MOFs) is regarded as a promising strategy to enhance Fenton-like performance. However, developing a facile and effective strategy to construct defective Fe-MOFs as highly efficient Fenton-like catalyst is still a challenge. Herein, MIL-100(Fe) (Def-MIL-100(Fe)) with missing ligands defects was synthesized by a simple heterogeneous reaction using zero-valent iron. The bisphenol A degradation efficiency in the Def-MIL-100(Fe)/H2O2 system reached up to 91.26% within 10min at pH 4 with a low catalyst dosage of 0.05g/L, while the perfect MIL-100(Fe) has almost no Fenton-like performance. It was observed that missing ligands defects in the Def-MIL-100(Fe) play a key role in the Fenton-like reaction. The missing ligands defects could increase the Lewis acidity for fast H2O2 adsorption and accelerate the electron transfer between FeII and FeIII cycling, leading to faster and more·OH generation. Moreover, the missing ligands defects could promote the mass transfer for improving·OH utilization efficiency. This work provides a novel strategy to construct defective Fe-MOFs as highly efficient Fenton-like catalyst to degrade organic pollutants in water.

Three-Dimensionally Printed Zero-Valent Copper with Hierarchically Porous Structures as an Efficient Fenton-like Catalyst for Enhanced Degradation of Tetracycline

Three-dimensionally printed materials show great performance and reliable stability in the removal of refractory organic pollutants in Fenton-like reactions. In this work, hierarchically porous zero-valent copper (3DHP-ZVC) was designed and fabricated via 3D printing and applied as a catalyst for the degradation of tetracycline (TC) through heterogeneous Fenton-like processes. It was found that the 3DHP-ZVC/H2O2 system could decompose over 93.2% of TC within 60 min, which is much superior to the homogeneous Cu2+/H2O2 system under similar conditions. The leaching concentration of Cu2+ ions in the 3DHP-ZVC/H2O2 system is 2.14 times lower than that in the Cu powder/H2O2 system in a neutral environment, which could be ascribed to the unique hierarchically porous structure of 3DHP-ZVC. Furthermore, 3DHP-ZVC exhibited compelling stability in 20 consecutive cycles. The effects of co-existing inorganic anions, adaptability, and pH resistance on the degradation of TC were also investigated. A series of experiments and characterizations revealed that Cu0 and superoxide radicals as reducing agents could facilitate the cycling of Cu(II)/Cu(I), thus enhancing the generation of hydroxyl radicals to degrade TC. This study provides new insights into employing promising 3D printing technology to develop high-reactivity, stable, and recycling-friendly components for wastewater treatment.

Pyrite Cinder as an Effective Fenton-like Catalyst for the Degradation of Reactive Azo Dye: Effects of Process Parameters and Complete Effluent Characterization

This research investigates the potential use of pyrite cinder (PC) as an efficient Fenton-like catalyst for the removal of the reactive azo dye Reactive Red 120 (RR120) from aqueous solutions. The characterization of its PC structure and composition confirmed its great potential to act as catalytic iron source in a heterogeneous Fenton system. Dye removal optimization was performed in terms of PC dosage (0.4–8 g/L), H2O2 concentration (2–25 mM), pH value (2–4.6), initial dye concentration (50–200 mg/L), and mixing time. The highest decolorization efficiency (92%) was achieved after a reaction time of 480 min under following conditions: RR120 = 50 mg/L, PC = 4 g/L, H2O2 = 10 mM, and pH = 3. After decolorization, an extensive analysis of the generated effluent was performed regarding metal leaching, mineralization, toxicity, and degradation product formation. The metal leaching indicated the necessity for a pH increase in order to remove the settled metal hydroxides. The mineralization efficiency was satisfactory, reaching 85% and 62% of the COD and TOC removal, respectively. The respirometry measurements and bioluminescence tests indicated the detoxification of the treated solution. The absorption spectra and GC/MS analysis confirmed the changes in the molecular structure in the form of the destruction of the azo bond, with a simpler aromatic and aliphatic intermediates formation. This study provides an effective method for removing azo dye in polluted water by employing waste tailings as alternative Fenton-like catalysts, while also using waste tailings as the secondary resource.

Modified birnessite MnO2 as efficient Fenton-like catalysts through electron transfer process between the simultaneously surface-activated peroxymonosulfate and pollutants.

The development of efficient and eco-friendly Mn-based hybrids for the degradation of biorefractory organic pollutants via peroxymonosulfate (PMS) activation is highly desired. In this study, a novel graphite nanosheet (GNs)-based Fe-Mn bimetallic oxide (Fe doped birnessite MnO2, FeMn/GNs) was synthesized under mild conditions. Compared with monometallic Fe or Mn oxide on GNs, FeMn/GNs exhibited a higher surface area, decreased Mn oxidation states, stronger interaction with GNs, and more active sites for PMS adsorption. Among different Fe/Mn ratios, Fe2Mn1/GNs showed the optimum performance for bisphenol A (BPA) degradation with the first-order rate constant of 0.22min-1, which was about 8.5 and 12.9 times higher than that of Mn/GNs and Fe/GNs, respectively. Different from the pollutant-catalyst-PMS electron transfer mechanism for Mn/GNs, the direct two-electron transfer in FeMn/GNs+PMS system, was mainly processed between the simultaneously activated BPA and PMS. This was probably based on the double adsorption sites of Fe and Mn species on the same catalyst: PMS was adsorbed by Fe species through hydroxyl groups, while BPA was mainly coordinated with Mn species due to the layered structure and hydrophobicity of the Mn oxide. This study is expected to provide the rational design of efficient Mn-based hybrids for PMS activation.

2D MOF derived cobalt and nitrogen-doped ultrathin oxygen-rich carbon nanosheets for efficient Fenton-like catalysis: Tuning effect of oxygen functional groups in close vicinity to Co-N sites.

Developing highly efficient catalysts for peroxymonosulfate (PMS) activation is an important issue in advanced oxidation processes (AOPs) technology. In this work, cobalt and nitrogen-doped ultrathin oxygen-rich carbon nanosheets derived from 2D metal-organic framework (MOF) were successfully fabricated. The as-prepared catalyst can effectively degrade tetracycline (TC) with a high reaction constant (0.088min-1). Quenching test, electron paramagnetic resonance (EPR) technology, and the electrochemical test indicate that the radical pathway plays a minor role in the degradation process, the 1O2 based nonradical pathway dominates the reaction. Experimental and density functional theory (DFT) studies revealed that the Co-N sites on the carbon structure serve as the dominant active sites, and the oxygen functional groups in close vicinity to Co-N sites can dramatically influence local electronic structure and its interaction with PMS molecule, a high correlation between the reaction constant and hydroxy groups content could be due to the Co-N sites close to hydroxyl groups has a moderate PMS adsorption energy. This work provides new insight into the design of highly efficient Fenton-like catalysts.

A novel Fenton-like catalyst and peroxymonosulfate activator of Mn3O4/λ-MnO2 for phenol degradation: Synergistic effect and mechanism

A low-cost and highly efficient Fenton-like catalyst desired to produce the hydroxyl radical (·OH) and sulfate radical (SO4·-) at the same time for environmental applications was successfully fabricated via a noval alcohol-thermal method. Remarkably, the Mn3O4/λ-MnO2 composite exhibited the highly efficient activation for peroxymonosulfate (PMS) and deep mineralization for phenol under visible-light irradiation. The phenol degradation fitted the pseudo-first-order reaction kinetics well with rate constant of 0.0455 min−1 for photo-Fenton-like system and 0.0340 min−1 for Fenton-like system, respectively. Based on the results of radical quantification experiments and electron spin resonance (ESR) tests, ·OH, SO4·- and superoxide radical (·O2–) species played imperative roles during the oxidation process. The active species were mainly derived from the multivalent manganese ions on the surface of Mn3O4/λ-MnO2 composite formed a cyclic loop and reacted with HSO5- of PMS, thus significantly enhancing the catalytic performance. Finally, the probable reaction mechanism of Mn3O4/λ-MnO2 catalyst activation of PMS in a Fenton-like system under solar irradiation or in dark were speculated. This work will provide a new idea for the practical application of PMS activation in the treatment of organic matters in the wastewater under solar light irradiation.

Different crystallographic Ni(OH)2 as highly efficient Fenton-like catalysts for sulfate radical activation.

By a simple hydrothermal method, a phase boundary between α- and β-Ni(OH)2 can be obtained. The Fenton-like performance of α@β-Ni(OH)2 is 1.56 times higher than that of single β-Ni(OH). α@β-Ni(OH)2 displays superior stability compared to α-Ni(OH)2, β-Ni(OH)2, and amorphous Ni(OH)2, which makes significant contributions to developing advanced catalysts in diverse fields.

Cobalt mediated perovskite as efficient Fenton-like catalysts for the tetracycline removal over a neutral condition: The importance of superoxide radical

Cobalt mediated perovskite oxides (Ca–Fe–Co-x) were prepared for heterogeneous Fenton-like, which exhibited excellent tetracycline (TC) degradation efficiency and wider pH suitability (3–11). Experimental results showed that Ca–Fe–Co-1.0 sample displayed the highest degradation rate could reach 80.5% under neutral conditions, and maintain at around 80% after four cycles. The analysis of degradation mechanism showed that the redox of Fe2+/Fe3+ and Co2+/Co3+ significant enhanced the activation of H2O2 to superoxide radical (∙O2−). Meanwhile, the hydroxyl radical (∙OH) was also detected by ESR analysis. In addition, the possible degradation pathway and mechanism of TC were deduced via UPLC-QTOF/MS analysis and density functional theory (DFT) calculations. The toxicity of TC and its intermediates were also evaluated by the ECOSAR software. The Ca–Fe–Co-1.0/nanocellulose aerogel (NCA) displayed highly removal efficiency of TC wastewater in the long-term operation conduction. This study provided a feasible method to design and synthesis heterogeneous Fenton-like catalysts for antibiotic degradation.

Utilizing scrap printed circuit boards to fabricate efficient Fenton-like catalysts for the removal of pharmaceutical diclofenac and ibuprofen from water

Pharmaceutical concentrations in waterways have now gradually increased to alarming levels, posing a threat to the environment and human health. The heterogeneous Fenton-based advanced oxidation process is a promising treatment process for cleaning water from organic pollutants. Utilizing waste-to-resource technologies, electronic waste can be transformed into practical weapons for environmental remediation. In this work, scrap printed circuit boards (PCBs) were used to prepare green, simple, and scalable heterogeneous H2O2 activators namely, non-carbonized catalyst (NC-PCB) under air combustion and carbonized catalyst (C-PCB) under nitrogen pyrolysis. Diclofenac (DCF) and ibuprofen (IBP) were used as model pharmaceutical pollutants to investigate the efficacy of the synthesized catalysts in Fenton-like oxidation. The morphology, composition, and photocatalytic activities of both catalysts were characterized by various analytical techniques. The effect of experimental factors such as catalyst/H2O2 dosages, solution pH, and initial concentrations on the removal rate was studied and optimized. Under optimum conditions, the degradation efficiencies for DCF and IBP using the NC-PCB catalyst were 86% and 66%, respectively, and 61% and 65.7% using C-CPB within 30 min. The TOC removal for DCF and IBP after 60 min was 61% and 50% using NC-CPB and 45% and 43% using C-CPB, respectively. Copper oxides in the catalysts plays the primary role in the degradation process. For five cycles, the catalysts have good reusability and low metal leaching. The degradation kinetics were followed, by a pseudo-first-order model. The present study is expected to provide a new approach for promoting Fenton-like wastewater treatment systems to practical application.

MIL-101(FeII3,Mn) with dual-reaction center as Fenton-like catalyst for highly efficient peroxide activation and phenol degradation

Metal organic frameworks are important Fenton-like materials in environment remediation. Nevertheless, the slow Fe(III)/Fe(II) cycling and low H2O2 utilization limit their application. In this study, we develop the ferrous bimetallic MIL-101(FeII3, Mn), which significantly enhanced catalytic performance (5.8 and 31.4-fold higher phenol removal rate and apparent rate constant, respectively) compared with the original MIL-101(Fe). The mechanisms are fully investigated by XPS, EPR and DFT. The Fe2+ substitution affords the mixed-valences of Fe(III)/Fe(II) in the frameworks, which serve as stronger sites for H2O2 activation. Mn in MIL-101(FeII3, Mn) can also function as another reaction center to activate H2O2. Catalysts could coordinate with the π–electrons of pollutants, resulting in the electron transfer from pollutants to MIL-101(FeII3, Mn). Moreover, electrons around Mn atoms tends to transfer to the region of Fe atoms owing to the electronegativity difference, inducing to strengthen the electron-rich Fe micro-region. Therefore, H2O2 was primarily adsorbed onto electron-rich regions where it would be efficiently reduced to •OH, contributing to a higher H2O2 utilization (81.2 %). This study opens new insight into design of Fe-based MOFs as highly efficient Fenton-like catalysts in wastewater treatment.

Mn2O3/Mn3O4-Cu1.5Mn1.5O4 spinel as an efficient Fenton-like catalyst activating persulfate for the degradation of bisphenol A: Superoxide radicals dominate the reaction

In this work, a Mn2O3/Mn3O4-Cu1.5Mn1.5O4 spinel was fabricated and utilised as a catalyst to activate peroxydisulfate (PDS) leading to degradation of bisphenol A (BPA). The results showed that the system exhibited an excellent turnover frequency (TOF) of 2.7 × 10−3 s−1 and high stability. The amount of ion leaching was small and the degree of mineralisation was up to 66.2%. Superoxide radicals (O2−) were determined to be the dominant active species in the system. ≡Mn(II) and oxygen vacancies (Vo) were found to be the main active sites at the catalyst surface. The activation of PDS by the spinel catalyst and the reduction of dissolved oxygen both contributed to the production of O2− species. The synergistic effect of ≡Cu(I)/≡Cu(II) and ≡Mn(II)/≡Mn(III) redox pairs enabled the reaction to occur continuously. These results suggest the promise of this novel spinel catalyst in the removal of refractory organic compounds due to its excellent performance and stability. The catalyst may thus have great utility for environmental remediation.

Performance and mechanism of FeS2/FeSxOy as highly effective Fenton-like catalyst for phenol degradation

ABSTRACT Developing a highly efficient Fenton-like catalyst working in a wide pH range is imperative to accomplish its practical wastewater treatment. Herein, FeS2/FeSxOy catalyst was synthesized by hydrothermal-solvothermal vulcanization with thioacetamide as a sulfur source. Characterization results confirmed FeS2/FeSxOy consisted of pyrite, kornelite, and szomolnokite. FeS2/FeSxOy exhibited superior catalytic activity toward H2O2 activation with more than 96% phenol removal within 5 min in pH 3.0 ∼ 8.0 at 30°C. Radical scavenging experiment and EPR analysis revealed both hydroxyl radicals (·OH) and superoxide anion radicals (O2·-) anticipated in phenol elimination, but ·OH played a dominant role. The detailed degradation experiments and density functional theory (DFT) calculation confirmed the vital role of FeS2 in enhancing phenol abatement. This study not only developed a highly active catalyst for H2O2 activation but also theoretically analyzed the FeS2 function in depth, which provided a guide for designing a highly efficient Fenton-like catalyst.