The contamination of water resources by phenolic compounds(PCs)presents a significant environmental hazard,necessitating the development of novel materials and methodologies for effective mitigation.In this study,a me...The contamination of water resources by phenolic compounds(PCs)presents a significant environmental hazard,necessitating the development of novel materials and methodologies for effective mitigation.In this study,a metallic copper-doped zeolitic imidazolate framework was pyrolyzed and designated as CuNC-20 for the activation of peroxymonosulfate(PMS)to degrade phenol(PE).Cu-NC-20 could effectively address the issue of metal agglomeration while simultaneously diminishing copper dissolution during the activation of PMS reactions.The Cu-NC-20 catalyst exhibited a rapid degradation rate for PE across a broad pH range(3-9)and demonstrated high tolerance towards coexisting ions.According to scavenger experiments and electron paramagnetic resonance analysis,singlet oxygen(^(1)O_(2))and high-valent copperoxo(Cu(Ⅲ))were the predominant reactive oxygen species,indicating that the system was nonradicaldominated during the degradation process.The quantitative structure-activity relationship(QSAR)between the oxidation rate constants of various substituted phenols and Hammett constants was established.It indicated that the Cu-NC-20/PMS system had the optimal oxidation rate constant withσ^(-)correlation and exhibited a typical electrophilic reaction pattern.This study provides a comprehensive understanding of the heterogeneous activation process for the selective removal of phenolic compounds.展开更多
Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization...Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization of sodium lignosulfonate and boric acid.By degrading sulfamethoxazole(SMX),CSB-750 obtained 98.7%removal and 81.4%mineralization within 30 min.In comparison with solo S or B doping,S and B co-doped carbon showed the coupling effect for enhanced catalysis.The rate constant(kobs)of 0.1679 min^(-1)was 22.38-and 279.83-fold higher than those of CS-750(0.0075 min^(-1))and CB-750(0.0006 min^(-1)),respectively.The degradation was efficient at strong acidic and weak basic conditions(pH 3-9).Substantial inhibition effect was presented at strong basic condition(pH 10.95)and in presence of CO_(3)^(2-).The CO_(3)^(2-)-caused inhibition was the combined result of the cooperation of pH and quenching O_(2)^(·-).Thiophene sulfur,BC_(3),BC_(2)O,and structural defects were identified as the active sites for PS activation.Radical and nonradical pathways were both involved in the CSB-750/PS/SMX system,where^(1)O_(2)dominated the degradation,SO_(4)^(·-),·OH and direct electron transfer played the subordinate role,and O_(2)^(·-)served as a precursor for the formation of partial^(1)O_(2).The toxicity of degradation system,the effect of real water matrix,and the reusability of carbocatalysts were comprehensively analyzed.Nine possible degradation pathways were proposed.This work focuses on the catalytic performance improvement through the coupling effect of S,B co-doping,and develops an advanced heteroatom doping system to fabricate carbonaceous persulfate activators.展开更多
Biochar-based transition metal catalysts have been identified as excellent peroxymonosulfate(PMS)activators for producing radicals used to degrade organic pollutants.However,the radical-dominated pathways for PMS acti...Biochar-based transition metal catalysts have been identified as excellent peroxymonosulfate(PMS)activators for producing radicals used to degrade organic pollutants.However,the radical-dominated pathways for PMS activation severely limit their practical applications in the degradation of organic pollutants from wastewater due to side reactions between radicals and the coexisting anions.Herein,bimetallic Fe/Mn-loaded hydroxyl-rich biochar(FeMn-OH-BC)is synthesized to activate PMS through nonradical-dominated pathways.The as-prepared FeMn-OH-BC exhibits excellent catalytic activity for degrading tetracycline at broad pH conditions ranging from 5 to 9,and about 85.0%of tetracycline is removed in 40 min.Experiments on studying the influences of various anions(HCO_(3)^(−),NO_(3)^(−),and H_(2)PO_(4)^(−))show that the inhibiting effect is negligible,suggesting that the FeMn-OHBC based PMS activation is dominated by nonradical pathways.Electron paramagnetic resonance measurements and quenching tests provide direct evidence to confirm that 1O2 is the major reactive oxygen species generated from FeMn-OH-BC based PMS activation.Theoretical calculations further reveal that the FeMn-OH sites in FeMn-OH-BC are dominant active sites for PMS activation,which have higher adsorption energy and stronger oxidative activity towards PMS than OH-BC sites.This work provides a new route for driving PMS activation by biochar-based transition metal catalysts through nonradical pathways.展开更多
The efficient degradation of antibiotics in wastewater is critical for addressing global water pollution challenges.Herein,we report an Fe-Co dual-atom catalyst anchored on a nitrogen-doped carbon matrix(FeCo/NC),whic...The efficient degradation of antibiotics in wastewater is critical for addressing global water pollution challenges.Herein,we report an Fe-Co dual-atom catalyst anchored on a nitrogen-doped carbon matrix(FeCo/NC),which demonstrates superior performance in peroxymonosulfate(PMS)activation and tetracycline(TC)degradation.This system achieves a remarkable TC removal efficiency of 91.2%,significantly outperforming single-atom catalysts.Mechanistic investigations reveal that FeCo/NC induces a unique spin-state reconstruction,optimizing its electronic structure and shifting the oxidative mechanism from a radical-driven pathway to a singlet oxygen(^(1)O_(2))-dominated nonradical process.Theoretical insights from density functional theory(DFT)calculations confirm the preferred ^(1)O_(2) generation pathway at FeCo active sites,with reduced energy barriers that enhance catalytic activity.Toxicological evaluations validate that TC degradation intermediates exhibit minimal ecological risks,reinforcing the environmental safety of this approach.The long-term stability of the FeCo/NC/PMS system was evaluated via a continuous-flow photocatalytic reactor.The above results reflect the superior catalytic activity and stability of the FeCo/NC/PMS system.This work establishes a paradigm for designing advanced dual-atom catalysts and provides critical insights for developing eco-friendly solutions to antibiotic-contaminated wastewater treatment.展开更多
基金the financial support from Sichuan Program of Science and Technology(No.2021ZDZX0012)the National Natural Science Foundation of China(No.52200105)。
文摘The contamination of water resources by phenolic compounds(PCs)presents a significant environmental hazard,necessitating the development of novel materials and methodologies for effective mitigation.In this study,a metallic copper-doped zeolitic imidazolate framework was pyrolyzed and designated as CuNC-20 for the activation of peroxymonosulfate(PMS)to degrade phenol(PE).Cu-NC-20 could effectively address the issue of metal agglomeration while simultaneously diminishing copper dissolution during the activation of PMS reactions.The Cu-NC-20 catalyst exhibited a rapid degradation rate for PE across a broad pH range(3-9)and demonstrated high tolerance towards coexisting ions.According to scavenger experiments and electron paramagnetic resonance analysis,singlet oxygen(^(1)O_(2))and high-valent copperoxo(Cu(Ⅲ))were the predominant reactive oxygen species,indicating that the system was nonradicaldominated during the degradation process.The quantitative structure-activity relationship(QSAR)between the oxidation rate constants of various substituted phenols and Hammett constants was established.It indicated that the Cu-NC-20/PMS system had the optimal oxidation rate constant withσ^(-)correlation and exhibited a typical electrophilic reaction pattern.This study provides a comprehensive understanding of the heterogeneous activation process for the selective removal of phenolic compounds.
基金financially supported by the GuangDong Basic and Applied Basic Research Foundation(Nos.2019A1515110649,2020A1515110271,2019A1515110244)the National Natural,Science Fund of China(No.51908127)+1 种基金the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2017)the Research Team in Dongguan University of Technology(No.TDYB2019013)。
文摘Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant remediation.For the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization of sodium lignosulfonate and boric acid.By degrading sulfamethoxazole(SMX),CSB-750 obtained 98.7%removal and 81.4%mineralization within 30 min.In comparison with solo S or B doping,S and B co-doped carbon showed the coupling effect for enhanced catalysis.The rate constant(kobs)of 0.1679 min^(-1)was 22.38-and 279.83-fold higher than those of CS-750(0.0075 min^(-1))and CB-750(0.0006 min^(-1)),respectively.The degradation was efficient at strong acidic and weak basic conditions(pH 3-9).Substantial inhibition effect was presented at strong basic condition(pH 10.95)and in presence of CO_(3)^(2-).The CO_(3)^(2-)-caused inhibition was the combined result of the cooperation of pH and quenching O_(2)^(·-).Thiophene sulfur,BC_(3),BC_(2)O,and structural defects were identified as the active sites for PS activation.Radical and nonradical pathways were both involved in the CSB-750/PS/SMX system,where^(1)O_(2)dominated the degradation,SO_(4)^(·-),·OH and direct electron transfer played the subordinate role,and O_(2)^(·-)served as a precursor for the formation of partial^(1)O_(2).The toxicity of degradation system,the effect of real water matrix,and the reusability of carbocatalysts were comprehensively analyzed.Nine possible degradation pathways were proposed.This work focuses on the catalytic performance improvement through the coupling effect of S,B co-doping,and develops an advanced heteroatom doping system to fabricate carbonaceous persulfate activators.
基金This work was financially supported by the talent starting-up project of research development fund of Zhejiang Agriculture and Forestry University(No.2034020103)the Overseas Expertise Introduction Project for Discipline Innovation(No.111 Project D18008).
文摘Biochar-based transition metal catalysts have been identified as excellent peroxymonosulfate(PMS)activators for producing radicals used to degrade organic pollutants.However,the radical-dominated pathways for PMS activation severely limit their practical applications in the degradation of organic pollutants from wastewater due to side reactions between radicals and the coexisting anions.Herein,bimetallic Fe/Mn-loaded hydroxyl-rich biochar(FeMn-OH-BC)is synthesized to activate PMS through nonradical-dominated pathways.The as-prepared FeMn-OH-BC exhibits excellent catalytic activity for degrading tetracycline at broad pH conditions ranging from 5 to 9,and about 85.0%of tetracycline is removed in 40 min.Experiments on studying the influences of various anions(HCO_(3)^(−),NO_(3)^(−),and H_(2)PO_(4)^(−))show that the inhibiting effect is negligible,suggesting that the FeMn-OHBC based PMS activation is dominated by nonradical pathways.Electron paramagnetic resonance measurements and quenching tests provide direct evidence to confirm that 1O2 is the major reactive oxygen species generated from FeMn-OH-BC based PMS activation.Theoretical calculations further reveal that the FeMn-OH sites in FeMn-OH-BC are dominant active sites for PMS activation,which have higher adsorption energy and stronger oxidative activity towards PMS than OH-BC sites.This work provides a new route for driving PMS activation by biochar-based transition metal catalysts through nonradical pathways.
基金supported by the Yunnan Province Education Department Scientific Research Fund Project(No.2024J0828)the Basic Research Project of Yunnan Province Science and Technology Department(No.202201AU070004)the National Natural Science Foundation of China(Nos.52272287 and 22268003).
文摘The efficient degradation of antibiotics in wastewater is critical for addressing global water pollution challenges.Herein,we report an Fe-Co dual-atom catalyst anchored on a nitrogen-doped carbon matrix(FeCo/NC),which demonstrates superior performance in peroxymonosulfate(PMS)activation and tetracycline(TC)degradation.This system achieves a remarkable TC removal efficiency of 91.2%,significantly outperforming single-atom catalysts.Mechanistic investigations reveal that FeCo/NC induces a unique spin-state reconstruction,optimizing its electronic structure and shifting the oxidative mechanism from a radical-driven pathway to a singlet oxygen(^(1)O_(2))-dominated nonradical process.Theoretical insights from density functional theory(DFT)calculations confirm the preferred ^(1)O_(2) generation pathway at FeCo active sites,with reduced energy barriers that enhance catalytic activity.Toxicological evaluations validate that TC degradation intermediates exhibit minimal ecological risks,reinforcing the environmental safety of this approach.The long-term stability of the FeCo/NC/PMS system was evaluated via a continuous-flow photocatalytic reactor.The above results reflect the superior catalytic activity and stability of the FeCo/NC/PMS system.This work establishes a paradigm for designing advanced dual-atom catalysts and provides critical insights for developing eco-friendly solutions to antibiotic-contaminated wastewater treatment.
