The present study aims to fabricate heterogeneous electro-Fenton(HEF)cathode catalysts for the in-situ generation of H2O2 and the degradation of organic pollutants in water.To achieve this,preparation of Fe and N co-d...The present study aims to fabricate heterogeneous electro-Fenton(HEF)cathode catalysts for the in-situ generation of H2O2 and the degradation of organic pollutants in water.To achieve this,preparation of Fe and N co-doped MXene composites(FeCN/MXene-x,where x represents the loading content of FeCN)and construction of the HEF system for the degradation of sulfathiazole(STZ)were carried out.The characterization results showed that Fe,C and N mainly existed in the form of Fe3C and Fe3N in the FeCN/MXene catalysts,which were favorable for promoting the ORR reaction in the HEF system.Among them,FeCN/MXene-2 exhibited the highest redox electron transfer rate and H2O2 selectivity(86%).The catalytic oxidation mechanism of the FeCN/MXene-2/HEF system was investigated by free radical quenching,electron paramagnetic resonance and frontier orbital theory studies.These studies demonstrated that the main active substances for the degradation of STZ were·OH and 1O2.In addition,the excellent stability and practical performance of the prepared cathodic catalysts were demonstrated by cycling experiments and real water sample tests.展开更多
The oxygen reduction reaction(ORR)holds significant potential for various energy conversion and utilization technologies.In particular,the two-electron(2e^(-))ORR process for the electro-synthesis of hydrogen peroxide...The oxygen reduction reaction(ORR)holds significant potential for various energy conversion and utilization technologies.In particular,the two-electron(2e^(-))ORR process for the electro-synthesis of hydrogen peroxide(H_(2)O_(2))facilitates the continuous production of this compound.Recently,the application of 2e^(-)ORR in electro-Fenton(EF)technology has garnered substantial attention within the wastewater treatment sector.Despite substantial advancements,challenges remain regarding the activity and stability of oxygen reduction catalysts,as well as the specific reaction conditions,which continue to limit the degradation efficiency of EF technology.Therefore,it is essential to examine the progress in research on 2e^(-)oxygen reduction catalysts and the optimization of EF reaction conditions.This review begins by summarizing the fundamental principles of ORR and EF technologies.It discusses the regulatory strategies for carbon-based and transition metal-based catalysts aimed at improving the yield and selectivity of H_(2)O_(2).Additionally,the optimization methods for EF reaction conditions are outlined,focusing on promoting the regeneration of Fe^(2+)and broadening the operational pH range.The review further elaborates on novel coupling technologies.Finally,it envisions future research prospects to enhance the practicality and feasibility of EF technology in wastewater treatment.展开更多
Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation...Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light （photo-Fenton） or electron current （electro-Fenton） was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.展开更多
As a novel advanced oxidation process (AOP), electro-Fenton process is powerful for degrading most organic compounds including toxic and non-biodegradable ones, and so has attracted great attention. This paper reviews...As a novel advanced oxidation process (AOP), electro-Fenton process is powerful for degrading most organic compounds including toxic and non-biodegradable ones, and so has attracted great attention. This paper reviews this process in detail including the mechanism, electrolytic bath, electrode materials, aerations and operation parameters. The application of electro-Fenton method in wastewater treatment is evaluated and summarized. Future work in this field is suggested, and three main directions of new electrode exploitation, development of assisted technologies and mechanistic study should be strengthened.展开更多
Electrochemical advanced oxidation processes (EAOPs) are effective and environmentally friendly for the treatment of refractory organic pollutants.Among EAOPs,heterogeneous electro-Fenton (EF) process with in-situ for...Electrochemical advanced oxidation processes (EAOPs) are effective and environmentally friendly for the treatment of refractory organic pollutants.Among EAOPs,heterogeneous electro-Fenton (EF) process with in-situ formation of hydrogen peroxide (H_(2)O_(2)) is an eco-friendly,cost-effective and easy-operable technology to generate hydroxyl radicals (;OH) with high redox potential.The generation of;OH is determined by the synergistic H_(2)O_(2)formation and activation.The surface catalytic mechanisms for H_(2)O_(2)activation in the heterogeneous EF process were discussed.Some required features such as heteroatom doping and oxygen groups for H_(2)O_(2)formation via selective two-electron oxygen reduction reaction (ORR) with carbonaceous electrode are summarized.The solid Fenton catalysts and integrated functional cathodes that widely used in heterogeneous EF for wastewater treatment are grouped into few classes.And the brief discussion on catalytic activity and stability of materials over different experimental conditions are given.In addition,the application of heterogeneous EF process on the remediation of emerging contaminants is provided.The challenges and future prospects of the heterogeneous EF processes about catalytic fall-off and multi-step/complex techniques for water purification are emphasized.展开更多
The current modified electro-Fenton system was designed to develop a more convenient and efficient undivided system for practical wastewater treatment.The system adopted a cathode portion that employed magnetic stirri...The current modified electro-Fenton system was designed to develop a more convenient and efficient undivided system for practical wastewater treatment.The system adopted a cathode portion that employed magnetic stirring instead of common oxygen gas diffusion or gas sparging to supply oxygen gas for the electrolyte solution.Key factors influencing the cathode fabrication and activit)were investigated.The degradation of acid fuchsine with a self-made graphite-polytetrafluorethylene cathode was studied using spectrophotometer.It was found that the cathode generated hydrogen peroxide with high current efficiency and the hydrogen peroxide yield of the cathode did not decay after 10 times reuse.With the Pt anode at a ferrous ion concentration of 0.5 mmol/L,a pH of 3,and using magnetic stirring,dye decolorization could be rapidly accomplished but the destruction of benzene rings and intermediates was fairly difficult.With a Fe anode,dye degradation was more complete.展开更多
FeVO4/CeO2 was applied in the electro-Fenton(EF)degradation of Methyl Orange(MO)as a model of wastewater pollution.The results of the characterization techniques indicate that FeVO4 with triclinic structure and face-c...FeVO4/CeO2 was applied in the electro-Fenton(EF)degradation of Methyl Orange(MO)as a model of wastewater pollution.The results of the characterization techniques indicate that FeVO4 with triclinic structure and face-centered cubic fluorite CeO2 maintained their structures during the nanocomposite synthesis.The effect of applied current intensity,initial pollutant concentration,initial pH,and catalyst weight was investigated.The MO removal reached 96.31%and chemical oxygen demand(COD)removal 70%for 60 min of the reaction.The presence of CeO2 in the nanocomposite plays a key role in H2O2 electro-generation as a significant factor in the electro-Fenton(EF)system.The metal leaching from FeVO4/CeO2 was negligible(cerium 4.1%,iron 4.3%,and vanadium 1.7%),which indicates that the active species in the nanocomposite are strongly interacting with each other and are stable.The performance of the nanocatalyst in real wastewaters,salty,and binary systems was acceptable and the pollutions were removed efficiently.The synergistic effect between V,Fe,and Ce could be account as the reason for the respectable function of FeVO4/CeO2.The electron transfer proceeds via Haber-Weiss mechanism.A degradation pathway was proposed through by-products analysis using gas chromatography-mass spectrometry(GC–MS)technique.The pseudo-first-order kinetic model described the obtained experimental results(R2=0.9906).The electro-Fenton system efficiency was improved by adding persulfate.The nanocomposite preserved almost its efficiency after six cycles.The obtained results demonstrate that the synergistic catalyst(FeVO4/CeO2)has the capability to introduce as a promising replacement of conventional catalysts in the electro-Fenton processes with brilliant proficiency.展开更多
New pollutant pharmaceutical and personal care products(PPCPs),especially antiviral drugs,have received increasing attention not only due to their increase in usage after the outbreak of COVID-19 epidemics but also du...New pollutant pharmaceutical and personal care products(PPCPs),especially antiviral drugs,have received increasing attention not only due to their increase in usage after the outbreak of COVID-19 epidemics but also due to their adverse impacts on water ecological environment.Electro-Fenton technology is an effective method to remove PPCPs from water.Novel particle electrodes(MMT/rGO/Fe_(3)O_(4))were synthesized by depositing Fe3O4 nanoparticles on reduced graphene oxide modified montmorillonite and acted as catalysts to promote oxidation performance in a three-dimensional electro-Fenton(3D-EF)system.The electrodes combined the catalytic property of Fe3O4,hydrophilicity of montmorillonite and electrical conductivity of graphene oxides,and applied for the degradation of Acyclovir(ACV)with high efficiency and ease of operation.At optimal condition,the degradation rate of ACV reached 100%within 120 min,and the applicable pH range could be 3 to 11 in the 3D-EF system.The stability and reusability of MMT/rGO/Fe_(3)O_(4)particle electrodes were also studied,the removal rate of ACV remained at 92%after 10 cycles,which was just slightly lower than that of the first cycle.Potential degradation mechanisms were also proposed by methanol quenching tests and FT-ICR-MS.展开更多
This study reports the removal of amoxicillin(AMX)in aqueous media using the electroFenton process in the presence of a graphite cathode recovered from used batteries.The impact of the relevant parameters on the elect...This study reports the removal of amoxicillin(AMX)in aqueous media using the electroFenton process in the presence of a graphite cathode recovered from used batteries.The impact of the relevant parameters on the electroFenton process,namely the applied current intensity,the temperature,the initial concentration of AMX and the initial concentration of ferrous ions were investigated.The results showed that the optimal values were:I=600 mA,T=25℃,[AMX]_(0)=0.082 mmol·L^( 1) and[Fe^(2+)]=1 mmol·L^(1),leading to 95%degradation and 74%mineralization.The model parameters of AMX mineralization were determined using nonlinear methods,showing that it follows a pseudosecondorder kinetic.The Energy consumption(EC)calculated under the optimal values was found to be 0.79 kWhg 1,which was of the same order of magnitude of those reported in other findings;while it is noteworthy that the electrodes used in our study are of a lower cost.展开更多
An ultra-efficient electro-Fenton catalyst with porous carbon coated Fe-Mo metal(FeMo@PC),was prepared by calcining MIL-53(Fe)@MoO_(3).This FeMo@PC-2 exhibited impressive catalytic performance for sulfamethazine(SMT)d...An ultra-efficient electro-Fenton catalyst with porous carbon coated Fe-Mo metal(FeMo@PC),was prepared by calcining MIL-53(Fe)@MoO_(3).This FeMo@PC-2 exhibited impressive catalytic performance for sulfamethazine(SMT)degradation with a high turnover frequency value(7.89 L/(g·min)),much better than most of reported catalysts.The mineralization current efficiency and electric energy consumption were 83.2%and 0.03 kWh/gTOC,respectively,at lowcurrent(5mA)and small dosage of catalyst(25.0mg/L).The removal rate of heterogeneous electro-Fenton(Hetero-EF)process catalyzed by FeMo@PC-2 was 4.58 times that of Fe@PC/Hetero-EF process.Because the internal-micro-electrolysis occurred between PC and Fe0,while the co-catalysis of Mo accelerated the rate-limiting step of the Fe^(3+)/Fe^(2+) cycle and greatly improved the H_(2)O_(2)utilization efficiency.The results of radical scavenger experiments and electron paramagnetic resonance confirmed the main role of surface-bound hydroxyl radical oxidation.This process was feasible to remove diverse organic contaminants such as phenol,2,4-dichlorophenoxyacetic acid,carbamazepine and SMT.This paper enlightened the importance of the doped Mo,which could greatly improve the activity of the iron-carbon heterogeneous catalyst derived from metal-organic frameworks in EF process for efficient removal of organic contaminants.展开更多
The Electro-Fenton(EF)process is one of the promising advanced oxidation processes(AOPs)for environmental remediation.The H_(2)O_(2) yield of EF process largely determines its performance on organic pollutants degrada...The Electro-Fenton(EF)process is one of the promising advanced oxidation processes(AOPs)for environmental remediation.The H_(2)O_(2) yield of EF process largely determines its performance on organic pollutants degradation.Conventional Pd-catalytic EF process generates H_(2)O_(2) via the combination reaction of anodic O_(2) and cathodic H;.However,the relatively expensive catalyst limits its application.Herein,a hybrid Pd/activated carbon(Pd/AC)-stainless steel mesh(SS)cathode(PACSS)was proposed,which enables more efficie nt H_(2)O_(2)generation.It utilizes AC,the support of Pd catalyst,as part of cathode for H_(2)O_(2) generation via 2-electron anodic O_(2) reduction,and SS serve as a current distributor.Moreover,H_(2)O_(2) could be catalytically decomposed upon AC to generate highly reactive·OH,which avoids the use of Fe;.Compared with conventional Pd catalyst,H_(2)O_(2) concentration obtained by PACSS cathode is248.2%higher,the O_(2)utilization efficiency was also increased from 3.2%to 10.8%.Within 50 min,26.3%,72.5%,and 94.0%H_(2)O_(2) was decomposed by Pd,AC,and Pd/AC.Fluorescence detection results implied that Pd/AC is effective upon H_(2)O_(2) activation for·OH generation.Finally,iron-free EF process enabled by PACSS cathode was examined to be effective for reactive blue 19(RB19)degradation.After continuous running for 10 cycles(500 min),the PACSS cathode was still stable for H_(2)O_(2)generation,H_(2)O_(2)activation,and RB19 degradation,showing its potential application for organic pollutants degradation without increase in the running cost.展开更多
Hydrogen peroxide(H_(2)O_(2))in situ electrosynthesis by O_(2)reduction reaction is a promising alternative to the conventional Fenton treatment of refractory wastewater.However,O_(2)mass transfer limitation,cathodic ...Hydrogen peroxide(H_(2)O_(2))in situ electrosynthesis by O_(2)reduction reaction is a promising alternative to the conventional Fenton treatment of refractory wastewater.However,O_(2)mass transfer limitation,cathodic catalyst selectivity,and electron transfer in O_(2)reduction remain major engineering obstacles.Here,we have proposed a systematic solution for efficient H_(2)O_(2)generation and its electro-Fenton(EF)application for refractory organic degradation based on the fabrication of a novel ZrO_(2)/CMK-3/PTFE cathode,in which polytetrafluoroethylene(PTFE)acted as a hydrophobic modifier to strengthen the O_(2)mass transfer,ZrO_(2)was adopted as a hydrophilic modifier to enhance the electron transfer of O_(2)reduction,and mesoporous carbon CMK-3 was utilized as a catalyst substrate to provide catalytic active sites.Moreover,feasible mass transfer of O_(2)from the hydrophobic to the hydrophilic layer was designed to increase the contact between O_(2)and the reaction interface.The H_(2)O_(2)yield of the ZrO_(2)/CMK-3/PTFE cathode was significantly improved by approximately 7.56 times compared to that of the co nventional gas diffusion cathode under the same conditions.The H_(2)O_(2)generation rate and Faraday efficiency reached125.98 mg·cm^(-2)·h^(-1)(normalized to 5674.04 mmol·g^(-1)·h^(-1)by catalyst loading)and 78.24%at-1.3 V versus standard hydrogen electrode(current density of-252 mA·cm^(-2)),respectively.The high H_(2)O_(2)yield ensured that sufficient OH was produced for excellent EF performance,resulting in a degradation efficiency of over 96%for refractory organics.This study offers a novel engineering solution for the efficient treatment of refractory wastewater using EF technology based on in situ high-yield H_(2)O_(2)electrosynthesis.展开更多
Herein,the application of a N-doped graphitic-carbon-coated iron nitride composite dispersed in a N-doped carbon framework(Fe_(3)N@NG/NC)is investigated as a heterogeneous electro-Fenton(HE-EF)catalyst for the efficie...Herein,the application of a N-doped graphitic-carbon-coated iron nitride composite dispersed in a N-doped carbon framework(Fe_(3)N@NG/NC)is investigated as a heterogeneous electro-Fenton(HE-EF)catalyst for the efficient removal of organics.The simultaneous carbonization and ammonia etching of iron-based metal organic framework(Fe-MOF)materials yielded well-dispersed N-doped carbon-coated Fe_(3)N nanoparticles with a diameter of~70 nm.The Fe_(3)N and pyridinic N endowed the composite with high HE-EF activity for decomposing the electrogenerated H_(2)O_(2) to•OH.The Fe_(3)N@NG/NC exhibited outstanding HE-EF performance in removing various organic pollutants with low iron leaching.A removal rate of 97-100%could be obtained for rhodamine B(RhB),dimethyl phthalate,methylene blue,and orange Ⅱ in 120 min at a pH of 5.0.When the solution pH was set to 3.0,5.0,7.0,and 9.0,the removal rate of RhB reached 100%,96%,92%,and 81%,respectively,in 60 min at an optimum voltage of 0.0 V(vs.reversible hydrogen electrode(RHE)).Moreover,the concentration of leached iron was expected to be below 0.03 mg/L in a wide pH range of 3.0-9.0.In addition,the RhB removal efficiency remained as high as 90%after six cycles in the reusability experiments.This work highlights the MOF-derived Fe_(3)N composite as an efficient HE-EF catalyst and the corresponding catalytic mechanism,which facilitates its application in wastewater treatment.展开更多
As a kind of rare-earth oxide,CeO_(2)has been considered as a great potential material for its abundant oxygen vacancies and catalysis activity in wastewater treatment.In this study,three ceria samples with different ...As a kind of rare-earth oxide,CeO_(2)has been considered as a great potential material for its abundant oxygen vacancies and catalysis activity in wastewater treatment.In this study,three ceria samples with different morphological structure were prepared,and their effect on contaminates degradation in electro-Fenton(E-Fenton)system was investigated.It is found that the morphology of CeO_(2)has great influence on promoting the performance of E-Fenton process.The rod-like CeO_(2)(R-CeO_(2))induced EFenton system shows higher azo dye X3 B removal and mineralization rates than cubs(C-CeO_(2))and octahedrons(O-CeO_(2)),and the degradation kinetic rate constants are 0.28,0.169 and 0.181 min^(-1)respectively,already surpass that of the blank one(0.120 min^(-1)).The H_(2)O_(2)generation capacity of R-CeO_(2)induced E-Fenton system is also superior to the others,and the corresponding Faraday current efficiency even increases to 166.2%at 2.5 min.Characterizations by scanning-transmission electron microscopy(STEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),electron spin resonance(ESR),Raman spectroscopy were conducted to disclose the mystery behind this phenomenon.The results indicate that the difference of surface oxygen vacancy density in different shaped CeO_(2)acts as a magic driving force for the accelerated oxygen reduction,and then leads to the enhanced degradation efficiency of E-Fenton system.This work provides a new insight into the development and application of rare-earth elements based catalyst in E-Fenton technology.展开更多
Membrane distillation(MD)is a promising alternative desalination technology,but the hydrophobic membrane cannot intercept volatile organic compounds(VOCs),resulting in aggravation in the quality of permeate.In term of...Membrane distillation(MD)is a promising alternative desalination technology,but the hydrophobic membrane cannot intercept volatile organic compounds(VOCs),resulting in aggravation in the quality of permeate.In term of this,electro-Fenton(EF)was coupled with sweeping gas membrane distillation(SGMD)in a more efficient way to construct an advanced oxidation barrier at the gas-liquid interface,so that the VOCs could be trapped in this layer to guarantee the water quality of the distillate.During the so-called EF-MD process,an interfacial interception barrier containing hydroxyl radical formed on the hydrophobic membrane surface.It contributed to the high phenol rejection of 90.2% with the permeate phenol concentration lower than 1.50 mg/L.Effective interceptions can be achieved in a wide temperature range,even though the permeate flux of phenol was also intensified.The EF-MD system was robust to high salinity and could electrochemically regenerate ferrous ions,which endowed the long-term stability of the system.This novel EF-MD configuration proposed a valuable strategy to intercept VOCs in MD and will broaden the application of MD in hypersaline wastewater treatment.展开更多
The flow-through electro-Fenton(EF-T)reactor with WBC cathode was designed to remove florfenicol(FF).The activated WBC cathode was prepared by facile carbonization and activation methods,and featured high specific sur...The flow-through electro-Fenton(EF-T)reactor with WBC cathode was designed to remove florfenicol(FF).The activated WBC cathode was prepared by facile carbonization and activation methods,and featured high specific surface area,natural multi-channel structure,abundant oxygen-containing groups,good hydrophilicity,and excellent O_(2)reducing capacity.WBC cathode was located above Ti/Ru-IrO_(2)mesh anode.O_(2)evolved at the anode was carried to the inner wall of channel of WBC by the force of buoyancy and water flow,which increases oxygen source of H_(2)O_(2)generation at the cathode.The flow-through system by using WBC electrode promote the mass transfer of O_(2)and FF.The production amount of H_(2)O_(2)at activated WBC was 32.2 mg/L,which was almost twice as much as that at non-activated WBC(15.0 mg/L).FF removal ratio in EF-T system was 98%,which was much higher than that of traditional flow-by electro-Fenton(EF-B,33%)or single electrooxidation system(EO,16%).EF-T system has the lowest energy consumption(4.367 kWh/kg)among the three electrochemical systems.The cathodic adsorption,anodic electrooxidation,and EF reaction are responsible for the degradation of FF.After five consecutive cycle experiments,FF removal ratio was still 98%,indicating WBC has the good stability.展开更多
Atomically dispersed single-atom catalysts(SACs)on carbon supports show great promise for H_(2)O_(2) electrosynthesis,but conventional wet chemistry methods using particulate carbon blacks in powder form have limited ...Atomically dispersed single-atom catalysts(SACs)on carbon supports show great promise for H_(2)O_(2) electrosynthesis,but conventional wet chemistry methods using particulate carbon blacks in powder form have limited their potential as two-electron(2^(e−))oxygen reduction reaction(ORR)catalysts.Here,we demonstrate high-performance Co SACs supported on a free-standing aligned carbon nanofiber(CNF)using electrospinning and arc plasma deposition(APD).Based on the surface oxidation treatment of aligned CNF and precise control of the deposition amount in a dry-based APD process,we successfully form densely populated Co SACs on aligned CNF.Through experimental analyses and density functional theory calculations,we reveal that Co SAC has a Co–N_(2)–O_(2) moiety with one epoxy group,leading to excellent 2^(e−)ORR activity.Furthermore,the aligned CNF significantly improves mass transfer in flow cells compared to randomly oriented CNF,showing an overpotential reduction of 30 mV and a 1.3-fold improvement(84.5%)in Faradaic efficiency,and finally achieves an outstanding production rate of 15.75 mol gcat^(−1) h^(−1) at 300 mA cm^(−2).The high-performance Co SAC supported on well-aligned CNF is also applied in an electro-Fenton process,demonstrating rapid removal of methylene blue and bisphenol F due to its exceptional 2e^(−)ORR activity.展开更多
The Electrochemical advanced oxidation method “Electro-Fenton” has been applied to remove 17β-estradiol (17β)- estra-1,3,5(10)-triéne-3,17-diol) in aqueous-acetonitrile mixture. This endocrine disrupting is a...The Electrochemical advanced oxidation method “Electro-Fenton” has been applied to remove 17β-estradiol (17β)- estra-1,3,5(10)-triéne-3,17-diol) in aqueous-acetonitrile mixture. This endocrine disrupting is a steroid hormone, releases from humans, animals and residual pharmaceuticals into the environmental water and usually causes suspected undesirable effects in aquatic organisms. The degradation of this organic compound by Electro-Fenton process was showed using a carbon felt cathode and platinum anode. The evolution of the concentration during treatment was followed up by high performance liquid chromatography (HPLC). The influence of operating conditions on the degradation of 17β-estradiol by Electro-Fenton step, such as initial concentration and catalyst concentration, has been investi- gated and discussed. We showed that the degradation reaction obeyed apparent first-order reaction kinetics, with absolute rate constant determined as 5.12 × 109 M–1 s–1 by competitive kinetics method taking Benzoic Acid as reference compound. The results confirm the efficiency of the Electro-Fenton process to degrade organic pollutant in aqueous-acetonitrile mixture.展开更多
基金supported by the National Key R&D Program of China(No.2019YFC0408500)the Key Science and Technology Projects of Anhui Province(No.202003a07020004)the Open Foundation of the Key Lab(Center)of Anhui Institute of Ecological Civilization(No.W2023JSKF0152).
文摘The present study aims to fabricate heterogeneous electro-Fenton(HEF)cathode catalysts for the in-situ generation of H2O2 and the degradation of organic pollutants in water.To achieve this,preparation of Fe and N co-doped MXene composites(FeCN/MXene-x,where x represents the loading content of FeCN)and construction of the HEF system for the degradation of sulfathiazole(STZ)were carried out.The characterization results showed that Fe,C and N mainly existed in the form of Fe3C and Fe3N in the FeCN/MXene catalysts,which were favorable for promoting the ORR reaction in the HEF system.Among them,FeCN/MXene-2 exhibited the highest redox electron transfer rate and H2O2 selectivity(86%).The catalytic oxidation mechanism of the FeCN/MXene-2/HEF system was investigated by free radical quenching,electron paramagnetic resonance and frontier orbital theory studies.These studies demonstrated that the main active substances for the degradation of STZ were·OH and 1O2.In addition,the excellent stability and practical performance of the prepared cathodic catalysts were demonstrated by cycling experiments and real water sample tests.
基金support of this research by the National Natural Science Foundation of China(22209021,22179034)the Natural Science Foundation of Heilongjiang Province(YQ2024B001)the Postdoctoral Science Foundation of Heilongjiang Province(LBH-Z24006)。
文摘The oxygen reduction reaction(ORR)holds significant potential for various energy conversion and utilization technologies.In particular,the two-electron(2e^(-))ORR process for the electro-synthesis of hydrogen peroxide(H_(2)O_(2))facilitates the continuous production of this compound.Recently,the application of 2e^(-)ORR in electro-Fenton(EF)technology has garnered substantial attention within the wastewater treatment sector.Despite substantial advancements,challenges remain regarding the activity and stability of oxygen reduction catalysts,as well as the specific reaction conditions,which continue to limit the degradation efficiency of EF technology.Therefore,it is essential to examine the progress in research on 2e^(-)oxygen reduction catalysts and the optimization of EF reaction conditions.This review begins by summarizing the fundamental principles of ORR and EF technologies.It discusses the regulatory strategies for carbon-based and transition metal-based catalysts aimed at improving the yield and selectivity of H_(2)O_(2).Additionally,the optimization methods for EF reaction conditions are outlined,focusing on promoting the regeneration of Fe^(2+)and broadening the operational pH range.The review further elaborates on novel coupling technologies.Finally,it envisions future research prospects to enhance the practicality and feasibility of EF technology in wastewater treatment.
基金The authors thank the "National" Science Council, Taiwan, China for financially supporting (No. NSC95- 2211-E-006-032).
文摘Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes （Fe^2＋/H2O2, UV/Fe^2＋/H2O2, and electrolysis/Fe^2＋/H2O2） in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore, UV light （photo-Fenton） or electron current （electro-Fenton） was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite, especially the electro-Fenton.
基金Project supported by the National Natural Science Foundation of China (No. 50478049)the Natural Science Foundation of Guangdong Province (No. 04011215), China
文摘As a novel advanced oxidation process (AOP), electro-Fenton process is powerful for degrading most organic compounds including toxic and non-biodegradable ones, and so has attracted great attention. This paper reviews this process in detail including the mechanism, electrolytic bath, electrode materials, aerations and operation parameters. The application of electro-Fenton method in wastewater treatment is evaluated and summarized. Future work in this field is suggested, and three main directions of new electrode exploitation, development of assisted technologies and mechanistic study should be strengthened.
基金funding from the National Natural Science Foundation of China (Nos.22076142,21677106,22076140)National Key Basic Research Program of China (No.2017YFA0403402)+2 种基金National Natural Science Foundation of China (No.U1932119)the Science & Technology Commission of Shanghai Municipality (No.14DZ2261100)the Fundamental Research Funds for the Central Universities。
文摘Electrochemical advanced oxidation processes (EAOPs) are effective and environmentally friendly for the treatment of refractory organic pollutants.Among EAOPs,heterogeneous electro-Fenton (EF) process with in-situ formation of hydrogen peroxide (H_(2)O_(2)) is an eco-friendly,cost-effective and easy-operable technology to generate hydroxyl radicals (;OH) with high redox potential.The generation of;OH is determined by the synergistic H_(2)O_(2)formation and activation.The surface catalytic mechanisms for H_(2)O_(2)activation in the heterogeneous EF process were discussed.Some required features such as heteroatom doping and oxygen groups for H_(2)O_(2)formation via selective two-electron oxygen reduction reaction (ORR) with carbonaceous electrode are summarized.The solid Fenton catalysts and integrated functional cathodes that widely used in heterogeneous EF for wastewater treatment are grouped into few classes.And the brief discussion on catalytic activity and stability of materials over different experimental conditions are given.In addition,the application of heterogeneous EF process on the remediation of emerging contaminants is provided.The challenges and future prospects of the heterogeneous EF processes about catalytic fall-off and multi-step/complex techniques for water purification are emphasized.
文摘The current modified electro-Fenton system was designed to develop a more convenient and efficient undivided system for practical wastewater treatment.The system adopted a cathode portion that employed magnetic stirring instead of common oxygen gas diffusion or gas sparging to supply oxygen gas for the electrolyte solution.Key factors influencing the cathode fabrication and activit)were investigated.The degradation of acid fuchsine with a self-made graphite-polytetrafluorethylene cathode was studied using spectrophotometer.It was found that the cathode generated hydrogen peroxide with high current efficiency and the hydrogen peroxide yield of the cathode did not decay after 10 times reuse.With the Pt anode at a ferrous ion concentration of 0.5 mmol/L,a pH of 3,and using magnetic stirring,dye decolorization could be rapidly accomplished but the destruction of benzene rings and intermediates was fairly difficult.With a Fe anode,dye degradation was more complete.
基金the Sharif University of Technol-ogy,the chemistry department,for financial support。
文摘FeVO4/CeO2 was applied in the electro-Fenton(EF)degradation of Methyl Orange(MO)as a model of wastewater pollution.The results of the characterization techniques indicate that FeVO4 with triclinic structure and face-centered cubic fluorite CeO2 maintained their structures during the nanocomposite synthesis.The effect of applied current intensity,initial pollutant concentration,initial pH,and catalyst weight was investigated.The MO removal reached 96.31%and chemical oxygen demand(COD)removal 70%for 60 min of the reaction.The presence of CeO2 in the nanocomposite plays a key role in H2O2 electro-generation as a significant factor in the electro-Fenton(EF)system.The metal leaching from FeVO4/CeO2 was negligible(cerium 4.1%,iron 4.3%,and vanadium 1.7%),which indicates that the active species in the nanocomposite are strongly interacting with each other and are stable.The performance of the nanocatalyst in real wastewaters,salty,and binary systems was acceptable and the pollutions were removed efficiently.The synergistic effect between V,Fe,and Ce could be account as the reason for the respectable function of FeVO4/CeO2.The electron transfer proceeds via Haber-Weiss mechanism.A degradation pathway was proposed through by-products analysis using gas chromatography-mass spectrometry(GC–MS)technique.The pseudo-first-order kinetic model described the obtained experimental results(R2=0.9906).The electro-Fenton system efficiency was improved by adding persulfate.The nanocomposite preserved almost its efficiency after six cycles.The obtained results demonstrate that the synergistic catalyst(FeVO4/CeO2)has the capability to introduce as a promising replacement of conventional catalysts in the electro-Fenton processes with brilliant proficiency.
基金the GDAS’Project of Science and Technology Development(No.2020GDASYL-20200103044)Key-Area Research and Development Program of Guangdong(No.2020B1111350002)+1 种基金the National Key R&D Program of China(No.2019YFC1805305)the Project of Water Resource Department of Guangdong Province(No.2017-18).
文摘New pollutant pharmaceutical and personal care products(PPCPs),especially antiviral drugs,have received increasing attention not only due to their increase in usage after the outbreak of COVID-19 epidemics but also due to their adverse impacts on water ecological environment.Electro-Fenton technology is an effective method to remove PPCPs from water.Novel particle electrodes(MMT/rGO/Fe_(3)O_(4))were synthesized by depositing Fe3O4 nanoparticles on reduced graphene oxide modified montmorillonite and acted as catalysts to promote oxidation performance in a three-dimensional electro-Fenton(3D-EF)system.The electrodes combined the catalytic property of Fe3O4,hydrophilicity of montmorillonite and electrical conductivity of graphene oxides,and applied for the degradation of Acyclovir(ACV)with high efficiency and ease of operation.At optimal condition,the degradation rate of ACV reached 100%within 120 min,and the applicable pH range could be 3 to 11 in the 3D-EF system.The stability and reusability of MMT/rGO/Fe_(3)O_(4)particle electrodes were also studied,the removal rate of ACV remained at 92%after 10 cycles,which was just slightly lower than that of the first cycle.Potential degradation mechanisms were also proposed by methanol quenching tests and FT-ICR-MS.
文摘This study reports the removal of amoxicillin(AMX)in aqueous media using the electroFenton process in the presence of a graphite cathode recovered from used batteries.The impact of the relevant parameters on the electroFenton process,namely the applied current intensity,the temperature,the initial concentration of AMX and the initial concentration of ferrous ions were investigated.The results showed that the optimal values were:I=600 mA,T=25℃,[AMX]_(0)=0.082 mmol·L^( 1) and[Fe^(2+)]=1 mmol·L^(1),leading to 95%degradation and 74%mineralization.The model parameters of AMX mineralization were determined using nonlinear methods,showing that it follows a pseudosecondorder kinetic.The Energy consumption(EC)calculated under the optimal values was found to be 0.79 kWhg 1,which was of the same order of magnitude of those reported in other findings;while it is noteworthy that the electrodes used in our study are of a lower cost.
基金supported by National Key R&D Program International Cooperation Project(No.2021YFE0106500)Natural Science Foundation of China(Nos.52170085 and 21976096)+2 种基金Tianjin Development Program for Innovation and Entrepreneurship,Key Project of Natural Science Foundation of Tianjin(No.21JCZDJC00320)Tianjin Post-graduate Students Research and Innovation Project(No.2019YJSB075)Fundamental Research Funds for the Central Universities,Nankai University(No.63221313).
文摘An ultra-efficient electro-Fenton catalyst with porous carbon coated Fe-Mo metal(FeMo@PC),was prepared by calcining MIL-53(Fe)@MoO_(3).This FeMo@PC-2 exhibited impressive catalytic performance for sulfamethazine(SMT)degradation with a high turnover frequency value(7.89 L/(g·min)),much better than most of reported catalysts.The mineralization current efficiency and electric energy consumption were 83.2%and 0.03 kWh/gTOC,respectively,at lowcurrent(5mA)and small dosage of catalyst(25.0mg/L).The removal rate of heterogeneous electro-Fenton(Hetero-EF)process catalyzed by FeMo@PC-2 was 4.58 times that of Fe@PC/Hetero-EF process.Because the internal-micro-electrolysis occurred between PC and Fe0,while the co-catalysis of Mo accelerated the rate-limiting step of the Fe^(3+)/Fe^(2+) cycle and greatly improved the H_(2)O_(2)utilization efficiency.The results of radical scavenger experiments and electron paramagnetic resonance confirmed the main role of surface-bound hydroxyl radical oxidation.This process was feasible to remove diverse organic contaminants such as phenol,2,4-dichlorophenoxyacetic acid,carbamazepine and SMT.This paper enlightened the importance of the doped Mo,which could greatly improve the activity of the iron-carbon heterogeneous catalyst derived from metal-organic frameworks in EF process for efficient removal of organic contaminants.
基金financially supported by the National Natural Science Foundation of China(Nos.52006049,51776055)the China Postdoctoral Science Foundation(Nos.2019M661293,2020T130149)。
文摘The Electro-Fenton(EF)process is one of the promising advanced oxidation processes(AOPs)for environmental remediation.The H_(2)O_(2) yield of EF process largely determines its performance on organic pollutants degradation.Conventional Pd-catalytic EF process generates H_(2)O_(2) via the combination reaction of anodic O_(2) and cathodic H;.However,the relatively expensive catalyst limits its application.Herein,a hybrid Pd/activated carbon(Pd/AC)-stainless steel mesh(SS)cathode(PACSS)was proposed,which enables more efficie nt H_(2)O_(2)generation.It utilizes AC,the support of Pd catalyst,as part of cathode for H_(2)O_(2) generation via 2-electron anodic O_(2) reduction,and SS serve as a current distributor.Moreover,H_(2)O_(2) could be catalytically decomposed upon AC to generate highly reactive·OH,which avoids the use of Fe;.Compared with conventional Pd catalyst,H_(2)O_(2) concentration obtained by PACSS cathode is248.2%higher,the O_(2)utilization efficiency was also increased from 3.2%to 10.8%.Within 50 min,26.3%,72.5%,and 94.0%H_(2)O_(2) was decomposed by Pd,AC,and Pd/AC.Fluorescence detection results implied that Pd/AC is effective upon H_(2)O_(2) activation for·OH generation.Finally,iron-free EF process enabled by PACSS cathode was examined to be effective for reactive blue 19(RB19)degradation.After continuous running for 10 cycles(500 min),the PACSS cathode was still stable for H_(2)O_(2)generation,H_(2)O_(2)activation,and RB19 degradation,showing its potential application for organic pollutants degradation without increase in the running cost.
基金National Natural Science Foundation of China(22176125,52200103 and22178220)China Postdoctoral Science Foundation(2022 M722081 and 2021 M692064)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Center for Advanced Electronic Materials and Devices and the instrumental Analysis Center,School of Environmental Science and Engineering,Shanghai Jiao Tong University for support。
文摘Hydrogen peroxide(H_(2)O_(2))in situ electrosynthesis by O_(2)reduction reaction is a promising alternative to the conventional Fenton treatment of refractory wastewater.However,O_(2)mass transfer limitation,cathodic catalyst selectivity,and electron transfer in O_(2)reduction remain major engineering obstacles.Here,we have proposed a systematic solution for efficient H_(2)O_(2)generation and its electro-Fenton(EF)application for refractory organic degradation based on the fabrication of a novel ZrO_(2)/CMK-3/PTFE cathode,in which polytetrafluoroethylene(PTFE)acted as a hydrophobic modifier to strengthen the O_(2)mass transfer,ZrO_(2)was adopted as a hydrophilic modifier to enhance the electron transfer of O_(2)reduction,and mesoporous carbon CMK-3 was utilized as a catalyst substrate to provide catalytic active sites.Moreover,feasible mass transfer of O_(2)from the hydrophobic to the hydrophilic layer was designed to increase the contact between O_(2)and the reaction interface.The H_(2)O_(2)yield of the ZrO_(2)/CMK-3/PTFE cathode was significantly improved by approximately 7.56 times compared to that of the co nventional gas diffusion cathode under the same conditions.The H_(2)O_(2)generation rate and Faraday efficiency reached125.98 mg·cm^(-2)·h^(-1)(normalized to 5674.04 mmol·g^(-1)·h^(-1)by catalyst loading)and 78.24%at-1.3 V versus standard hydrogen electrode(current density of-252 mA·cm^(-2)),respectively.The high H_(2)O_(2)yield ensured that sufficient OH was produced for excellent EF performance,resulting in a degradation efficiency of over 96%for refractory organics.This study offers a novel engineering solution for the efficient treatment of refractory wastewater using EF technology based on in situ high-yield H_(2)O_(2)electrosynthesis.
文摘Herein,the application of a N-doped graphitic-carbon-coated iron nitride composite dispersed in a N-doped carbon framework(Fe_(3)N@NG/NC)is investigated as a heterogeneous electro-Fenton(HE-EF)catalyst for the efficient removal of organics.The simultaneous carbonization and ammonia etching of iron-based metal organic framework(Fe-MOF)materials yielded well-dispersed N-doped carbon-coated Fe_(3)N nanoparticles with a diameter of~70 nm.The Fe_(3)N and pyridinic N endowed the composite with high HE-EF activity for decomposing the electrogenerated H_(2)O_(2) to•OH.The Fe_(3)N@NG/NC exhibited outstanding HE-EF performance in removing various organic pollutants with low iron leaching.A removal rate of 97-100%could be obtained for rhodamine B(RhB),dimethyl phthalate,methylene blue,and orange Ⅱ in 120 min at a pH of 5.0.When the solution pH was set to 3.0,5.0,7.0,and 9.0,the removal rate of RhB reached 100%,96%,92%,and 81%,respectively,in 60 min at an optimum voltage of 0.0 V(vs.reversible hydrogen electrode(RHE)).Moreover,the concentration of leached iron was expected to be below 0.03 mg/L in a wide pH range of 3.0-9.0.In addition,the RhB removal efficiency remained as high as 90%after six cycles in the reusability experiments.This work highlights the MOF-derived Fe_(3)N composite as an efficient HE-EF catalyst and the corresponding catalytic mechanism,which facilitates its application in wastewater treatment.
基金Project supported by Key R&D Program of Hubei Province(2020BCB062)Fundamental Research Funds for the Central Universities(CZP20005,CZQ21028)。
文摘As a kind of rare-earth oxide,CeO_(2)has been considered as a great potential material for its abundant oxygen vacancies and catalysis activity in wastewater treatment.In this study,three ceria samples with different morphological structure were prepared,and their effect on contaminates degradation in electro-Fenton(E-Fenton)system was investigated.It is found that the morphology of CeO_(2)has great influence on promoting the performance of E-Fenton process.The rod-like CeO_(2)(R-CeO_(2))induced EFenton system shows higher azo dye X3 B removal and mineralization rates than cubs(C-CeO_(2))and octahedrons(O-CeO_(2)),and the degradation kinetic rate constants are 0.28,0.169 and 0.181 min^(-1)respectively,already surpass that of the blank one(0.120 min^(-1)).The H_(2)O_(2)generation capacity of R-CeO_(2)induced E-Fenton system is also superior to the others,and the corresponding Faraday current efficiency even increases to 166.2%at 2.5 min.Characterizations by scanning-transmission electron microscopy(STEM),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),electron spin resonance(ESR),Raman spectroscopy were conducted to disclose the mystery behind this phenomenon.The results indicate that the difference of surface oxygen vacancy density in different shaped CeO_(2)acts as a magic driving force for the accelerated oxygen reduction,and then leads to the enhanced degradation efficiency of E-Fenton system.This work provides a new insight into the development and application of rare-earth elements based catalyst in E-Fenton technology.
基金supported by the National Natural Science Foundation of China(Nos.52200111,51978651,and 51878049)the China Postdoctoral Science Foundation(No.2021M703407)the special fund from the State Key Joint Laboratory of Environment Simulation and Pollution Control(Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences(No.21Z01ESPCR)。
文摘Membrane distillation(MD)is a promising alternative desalination technology,but the hydrophobic membrane cannot intercept volatile organic compounds(VOCs),resulting in aggravation in the quality of permeate.In term of this,electro-Fenton(EF)was coupled with sweeping gas membrane distillation(SGMD)in a more efficient way to construct an advanced oxidation barrier at the gas-liquid interface,so that the VOCs could be trapped in this layer to guarantee the water quality of the distillate.During the so-called EF-MD process,an interfacial interception barrier containing hydroxyl radical formed on the hydrophobic membrane surface.It contributed to the high phenol rejection of 90.2% with the permeate phenol concentration lower than 1.50 mg/L.Effective interceptions can be achieved in a wide temperature range,even though the permeate flux of phenol was also intensified.The EF-MD system was robust to high salinity and could electrochemically regenerate ferrous ions,which endowed the long-term stability of the system.This novel EF-MD configuration proposed a valuable strategy to intercept VOCs in MD and will broaden the application of MD in hypersaline wastewater treatment.
基金supported by the National Science Fund for Distinguished Young Scholars(No.51625801)Major Science and Technology Program for Water Pollution Control and Treatment in China(No.2017ZX07202-001-007)+4 种基金Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2017)Guangdong Provincial Science and Technology Project(No.2017A020216014)the National Natural Science Foundation of China(No.21777106)Pearl River S&T Nova Program of Guangzhou,China(No.201710010065)Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology(No.2020B1212060022)。
文摘The flow-through electro-Fenton(EF-T)reactor with WBC cathode was designed to remove florfenicol(FF).The activated WBC cathode was prepared by facile carbonization and activation methods,and featured high specific surface area,natural multi-channel structure,abundant oxygen-containing groups,good hydrophilicity,and excellent O_(2)reducing capacity.WBC cathode was located above Ti/Ru-IrO_(2)mesh anode.O_(2)evolved at the anode was carried to the inner wall of channel of WBC by the force of buoyancy and water flow,which increases oxygen source of H_(2)O_(2)generation at the cathode.The flow-through system by using WBC electrode promote the mass transfer of O_(2)and FF.The production amount of H_(2)O_(2)at activated WBC was 32.2 mg/L,which was almost twice as much as that at non-activated WBC(15.0 mg/L).FF removal ratio in EF-T system was 98%,which was much higher than that of traditional flow-by electro-Fenton(EF-B,33%)or single electrooxidation system(EO,16%).EF-T system has the lowest energy consumption(4.367 kWh/kg)among the three electrochemical systems.The cathodic adsorption,anodic electrooxidation,and EF reaction are responsible for the degradation of FF.After five consecutive cycle experiments,FF removal ratio was still 98%,indicating WBC has the good stability.
基金This work was supported by the KIST Institutional Program(2E32461)the NationalResearch Council of Science&Technology(NST)grant(CPS21041-100)+1 种基金the National Research Foundation ofKorea(NRF)grant funded by the Korea Government(MSIT)(No.RS-2023-00209940,NRF-2022R 1F1A1068725, NRF-2022M3H4A7046278)Korea EnvironmentIndustry&Technology Institute(KEITI)through theEcological Imitation-based Environmental Pollution Man-agement Technology Development Project,funded by theKorea Ministry of Environment(MOE)(2021002800005).
文摘Atomically dispersed single-atom catalysts(SACs)on carbon supports show great promise for H_(2)O_(2) electrosynthesis,but conventional wet chemistry methods using particulate carbon blacks in powder form have limited their potential as two-electron(2^(e−))oxygen reduction reaction(ORR)catalysts.Here,we demonstrate high-performance Co SACs supported on a free-standing aligned carbon nanofiber(CNF)using electrospinning and arc plasma deposition(APD).Based on the surface oxidation treatment of aligned CNF and precise control of the deposition amount in a dry-based APD process,we successfully form densely populated Co SACs on aligned CNF.Through experimental analyses and density functional theory calculations,we reveal that Co SAC has a Co–N_(2)–O_(2) moiety with one epoxy group,leading to excellent 2^(e−)ORR activity.Furthermore,the aligned CNF significantly improves mass transfer in flow cells compared to randomly oriented CNF,showing an overpotential reduction of 30 mV and a 1.3-fold improvement(84.5%)in Faradaic efficiency,and finally achieves an outstanding production rate of 15.75 mol gcat^(−1) h^(−1) at 300 mA cm^(−2).The high-performance Co SAC supported on well-aligned CNF is also applied in an electro-Fenton process,demonstrating rapid removal of methylene blue and bisphenol F due to its exceptional 2e^(−)ORR activity.
文摘The Electrochemical advanced oxidation method “Electro-Fenton” has been applied to remove 17β-estradiol (17β)- estra-1,3,5(10)-triéne-3,17-diol) in aqueous-acetonitrile mixture. This endocrine disrupting is a steroid hormone, releases from humans, animals and residual pharmaceuticals into the environmental water and usually causes suspected undesirable effects in aquatic organisms. The degradation of this organic compound by Electro-Fenton process was showed using a carbon felt cathode and platinum anode. The evolution of the concentration during treatment was followed up by high performance liquid chromatography (HPLC). The influence of operating conditions on the degradation of 17β-estradiol by Electro-Fenton step, such as initial concentration and catalyst concentration, has been investi- gated and discussed. We showed that the degradation reaction obeyed apparent first-order reaction kinetics, with absolute rate constant determined as 5.12 × 109 M–1 s–1 by competitive kinetics method taking Benzoic Acid as reference compound. The results confirm the efficiency of the Electro-Fenton process to degrade organic pollutant in aqueous-acetonitrile mixture.
