Sulfite (S(IV)) is a promising substitute for sulfate radical-based advanced oxidation processes.Here,a composite of in-situ anchoring Ni Co_(2)O_(4)nanosheets on biochar (BC) was firstly employed as a heterogeneous a...Sulfite (S(IV)) is a promising substitute for sulfate radical-based advanced oxidation processes.Here,a composite of in-situ anchoring Ni Co_(2)O_(4)nanosheets on biochar (BC) was firstly employed as a heterogeneous activator for sulfite (Ni Co_(2)O_(4)@BC-sulfite) to degrade atrazine (ATZ) in the neutral environment.The synergistic coupling of BC and Ni Co_(2)O_(4)endows the resulting composite excellent catalytic activity.82% of the degradation ratio of ATZ (1 mg/L) could be achieved within 10 min at initial concentrations of 0.6 g/L Ni Co_(2)O_(4)@BC,3.0 mmol/L sulfite in neutral environment.When further supplementing sulfite into the system at 20 min (considering the depletion of sulfite),outstanding degradation efficiency (100%) were achieved in the next 10 min without any other energy input by the Ni Co_(2)O_(4)@BC-sulfite system.The features of the prepared catalysts and the effects of some key parameters on ATZ degradation were systematically examined.A strong inner-sphere complexation (≡Co_(2)+/Ni^(2+)-SO_(3)^(2-)) was explored between sulfite and the metal sites on the Ni Co_(2)O_(4)@BC surface.The redox cycle of the surface metal efficiently mediated sulfite activation and triggered the series radical chain reactions.The generated radicals,in particular the surface-bound radicals were involved in ATZ degradation.High performance liquid chromatography-tandem mass spectrometry (LC-MS) technique was used to detect the degradation intermediates.Density functional theory (DFT) calculations were performed to illustrate the possible degradation pathways of ATZ.Finally,an underlying mechanism for ATZ removal was proposed.The present study offered a low-cost and sustainable catalyst for sulfite activation to remove ATZ in an environmentally friendly manner from wastewater.展开更多
Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been suc...Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been successfully synthesized by one-step solvothermal method.It was found that both catalysts could efficiently activate S(IV),with rapid reductive dechlorination and then oxidative degradation of a recalcitrant antibiotic chloramphenicol(CAP).Characterizations revealed that CoFe^(2)O_(4) spinels were tightly coated on the carbon bases(GO and CNTs),with effectiveness of the internal transfer of electrons.O_(2)˙−was identified for the reductive dechlorination of CAP,with simultaneously detection of both•OH and SO_(4)^(˙−)responsible for further oxidative degradation.The sulfur oxygen radical conversion reactions and molecular oxygen activation would occur together upon the carbon-based spinels.Spatial-separated interfacial reductive-oxidation of CAP would occur with dechlorination of CAP by O_(2)^(˙−)on the carbon bases,and oxidative degradation of intermediates by SO_(4)^(˙−/•)OH upon the CoFe^(2)O_(4) catalysts.展开更多
Sulfite(SO_(3)^(2−))activation is one of the most potential sulfate-radical-based advanced oxidation processes,and the catalysts with high efficiency and low-cost are greatly desired.In this study,the cobalt nanoparti...Sulfite(SO_(3)^(2−))activation is one of the most potential sulfate-radical-based advanced oxidation processes,and the catalysts with high efficiency and low-cost are greatly desired.In this study,the cobalt nanoparticles embedded in nitrogen-doped graphite layers(Co@NC),were used to activate SO32−for removal of Methyl Orange in aqueous solution.The Co@NC catalysts were synthesized via pyrolysis of Co^(2+)-based metal-organic framework(Co-MOF),where CoO was firstly formed at 400℃ and then partially reduced to Co nanoparticles embedded in carbon layers at 800℃.The Co@NC catalysts were more active than other cobaltbased catalysts such as Co^(2+),Co_(3)O_(4) and CoFe_(2)O_(4),due to the synergistic effect of metallic Co and CoxOy.A series of chain reaction between Co species and dissolved oxygen was established,with the production and transformation of SO_(3)•−,SO_(5)^(2−),and subsequent active radicals SO_(4)•−and HO•.In addition,HCO_(3)−was found to play a key role in the reaction by complexing with Co species on the surface of the catalysts.The results provide a new promising strategy by using the Co@NC catalyst for SO3_(2)−oxidation to promote organic pollutants degradation.展开更多
The ubiquity of refractory organic matter in aquatic environments necessitates innovative removal strategies.Sulfate radical-based advanced oxidation has emerged as an attractive solution,offering high selectivity,end...The ubiquity of refractory organic matter in aquatic environments necessitates innovative removal strategies.Sulfate radical-based advanced oxidation has emerged as an attractive solution,offering high selectivity,enduring efficacy,and anti-interference ability.Among many technologies,sulfite activation,leveraging its cost-effectiveness and lower toxicity compared to conventional persulfates,stands out.Yet,the activation process often relies on transition metals,suffering from low atom utilization.Here we introduce a series of single-atom catalysts(SACs)employing transition metals on g-C_(3)N_(4)substrates,effectively activating sulfite for acetaminophen degradation.We highlight the superior performance of Fe/CN,which demonstrates a degradation rate constant significantly surpassing those of Ni/CN and Cu/CN.Our investigation into the electronic and spin polarization characteristics of these catalysts reveals their critical role in catalytic efficiency,with oxysulfur radical-mediated reactions predominating.Notably,under visible light,the catalytic activity is enhanced,attributed to an increased generation of oxysulfur radicals and a strengthened electron donation-back donation dynamic.The proximity of Fe/CN's d-band center to the Fermi level,alongside its high spin polarization,is shown to improve sulfite adsorption and reduce the HOMO-LUMO gap,thereby accelerating photo-assisted sulfite activation.This work advances the understanding of SACs in environmental applications and lays the groundwork for future water treatment technologies.展开更多
基金supported by the National Science Foundation of China (Nos.22076057,21777052)the National Key R&D Program of China (No.2018YFC1802003)+1 种基金the Project for Application Foundation Frontier for Wuhan (No.2019020701011486)The Program of Introducing Talents of Discipline to Universities of China (111 program,B17019)。
文摘Sulfite (S(IV)) is a promising substitute for sulfate radical-based advanced oxidation processes.Here,a composite of in-situ anchoring Ni Co_(2)O_(4)nanosheets on biochar (BC) was firstly employed as a heterogeneous activator for sulfite (Ni Co_(2)O_(4)@BC-sulfite) to degrade atrazine (ATZ) in the neutral environment.The synergistic coupling of BC and Ni Co_(2)O_(4)endows the resulting composite excellent catalytic activity.82% of the degradation ratio of ATZ (1 mg/L) could be achieved within 10 min at initial concentrations of 0.6 g/L Ni Co_(2)O_(4)@BC,3.0 mmol/L sulfite in neutral environment.When further supplementing sulfite into the system at 20 min (considering the depletion of sulfite),outstanding degradation efficiency (100%) were achieved in the next 10 min without any other energy input by the Ni Co_(2)O_(4)@BC-sulfite system.The features of the prepared catalysts and the effects of some key parameters on ATZ degradation were systematically examined.A strong inner-sphere complexation (≡Co_(2)+/Ni^(2+)-SO_(3)^(2-)) was explored between sulfite and the metal sites on the Ni Co_(2)O_(4)@BC surface.The redox cycle of the surface metal efficiently mediated sulfite activation and triggered the series radical chain reactions.The generated radicals,in particular the surface-bound radicals were involved in ATZ degradation.High performance liquid chromatography-tandem mass spectrometry (LC-MS) technique was used to detect the degradation intermediates.Density functional theory (DFT) calculations were performed to illustrate the possible degradation pathways of ATZ.Finally,an underlying mechanism for ATZ removal was proposed.The present study offered a low-cost and sustainable catalyst for sulfite activation to remove ATZ in an environmentally friendly manner from wastewater.
基金financially-supported by the National Natural Science Foundation of China(Nos.21677055,22006045 and 21407052)the National Key Technical Research and Development Program of China(No.2019YFC1805204)+1 种基金Leading Plan for Scientific and Technological Innovation of High-tech Industries of Hunan Province(No.2021GK4060)the Fundamental Research Funds for the Central Universities,HUST(No.2017KFXKJC004).
文摘Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been successfully synthesized by one-step solvothermal method.It was found that both catalysts could efficiently activate S(IV),with rapid reductive dechlorination and then oxidative degradation of a recalcitrant antibiotic chloramphenicol(CAP).Characterizations revealed that CoFe^(2)O_(4) spinels were tightly coated on the carbon bases(GO and CNTs),with effectiveness of the internal transfer of electrons.O_(2)˙−was identified for the reductive dechlorination of CAP,with simultaneously detection of both•OH and SO_(4)^(˙−)responsible for further oxidative degradation.The sulfur oxygen radical conversion reactions and molecular oxygen activation would occur together upon the carbon-based spinels.Spatial-separated interfacial reductive-oxidation of CAP would occur with dechlorination of CAP by O_(2)^(˙−)on the carbon bases,and oxidative degradation of intermediates by SO_(4)^(˙−/•)OH upon the CoFe^(2)O_(4) catalysts.
基金supported by the National Natural Science Foundation of China(No.51978542)Special Project of the Central Committee Guides Local Science and Technology Development of Hubei Province(No.2019ZYYD073)
文摘Sulfite(SO_(3)^(2−))activation is one of the most potential sulfate-radical-based advanced oxidation processes,and the catalysts with high efficiency and low-cost are greatly desired.In this study,the cobalt nanoparticles embedded in nitrogen-doped graphite layers(Co@NC),were used to activate SO32−for removal of Methyl Orange in aqueous solution.The Co@NC catalysts were synthesized via pyrolysis of Co^(2+)-based metal-organic framework(Co-MOF),where CoO was firstly formed at 400℃ and then partially reduced to Co nanoparticles embedded in carbon layers at 800℃.The Co@NC catalysts were more active than other cobaltbased catalysts such as Co^(2+),Co_(3)O_(4) and CoFe_(2)O_(4),due to the synergistic effect of metallic Co and CoxOy.A series of chain reaction between Co species and dissolved oxygen was established,with the production and transformation of SO_(3)•−,SO_(5)^(2−),and subsequent active radicals SO_(4)•−and HO•.In addition,HCO_(3)−was found to play a key role in the reaction by complexing with Co species on the surface of the catalysts.The results provide a new promising strategy by using the Co@NC catalyst for SO3_(2)−oxidation to promote organic pollutants degradation.
基金Financial support from the National Natural Science Foundation of China(52270068)the open Project of the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(QG202225)+1 种基金the Heilongjiang Touyan Innovation Team Program was highly appreciatedWe would also like to thank Dr.Shibo Xi of Singapore Synchrotron Light Source for his help in catalyst characterization.
文摘The ubiquity of refractory organic matter in aquatic environments necessitates innovative removal strategies.Sulfate radical-based advanced oxidation has emerged as an attractive solution,offering high selectivity,enduring efficacy,and anti-interference ability.Among many technologies,sulfite activation,leveraging its cost-effectiveness and lower toxicity compared to conventional persulfates,stands out.Yet,the activation process often relies on transition metals,suffering from low atom utilization.Here we introduce a series of single-atom catalysts(SACs)employing transition metals on g-C_(3)N_(4)substrates,effectively activating sulfite for acetaminophen degradation.We highlight the superior performance of Fe/CN,which demonstrates a degradation rate constant significantly surpassing those of Ni/CN and Cu/CN.Our investigation into the electronic and spin polarization characteristics of these catalysts reveals their critical role in catalytic efficiency,with oxysulfur radical-mediated reactions predominating.Notably,under visible light,the catalytic activity is enhanced,attributed to an increased generation of oxysulfur radicals and a strengthened electron donation-back donation dynamic.The proximity of Fe/CN's d-band center to the Fermi level,alongside its high spin polarization,is shown to improve sulfite adsorption and reduce the HOMO-LUMO gap,thereby accelerating photo-assisted sulfite activation.This work advances the understanding of SACs in environmental applications and lays the groundwork for future water treatment technologies.
