4-Nitrophenol(4-NP),a toxic and persistent pollutant in chemical wastewater,presents significant challenges in degradation and mineralization.Conventional ozone oxidation catalysts are hindered by low efficiency,mass ...4-Nitrophenol(4-NP),a toxic and persistent pollutant in chemical wastewater,presents significant challenges in degradation and mineralization.Conventional ozone oxidation catalysts are hindered by low efficiency,mass transfer constraints and metal leaching,necessitating the development of stable and efficient catalysts.Herein,BCn-H/MS,the derivative of Bi(Ce)-MOF,was prepared by in situ incorporation,thermal decomposition and acid etching.The resulting materials were characterized and employed in catalytic ozonation for the reduction of 4-NP.Under the specific experimental conditions of the O_(3)+BC0.3-H/MS system,the total organic carbon(TOC)and chemical oxygen demand(COD)removal rates of 4-NP were observed to reach 94.6%and 91.8%within 30 min,respectively.These two parameters were improved by raising the initial pH,reducing the pollutant concentration and increasing the catalyst dosage.The abundant oxygen vacancies(OVs)were regarded as the pivotal catalytic site of BC0.3-H/MS,which was conducive to the adsorption of O_(3) and the acceleration of the formation of reactive oxygen species(ROS).The regular hollow square structure effectively boosted the specific surface area,increased OVs exposure and accelerated the adsorption and mass transfer process.The electron paramagnetic resonance(EPR)results demonstrated that the primary ROS engaged in the degradation reaction were⋅OH and⋅O_(2)−.BC0.3-H/MS demonstrated excellent stability and reusability in cyclic experiments.Toxicity analysis revealed that the O_(3)+BC0.3-H/MS system exhibited an effective detoxification effect.Ultimately,the primary degradation pathway of 4-NP was proposed through liquid chromatography-mass spectroscopy(LC-MS)and in-situ diffuse reflectance infrared fourier-transform spectroscopy(DRIFTS)analyses at varying reaction times.展开更多
The limited redox capability of photocatalysts often leads to harmful NO_(2) byproduct formation during photocatalytic NO oxidation.Herein,Bi_(4)Ti_(3)O_(12) nanosheets modified with plasmonic metallic bismuth and abu...The limited redox capability of photocatalysts often leads to harmful NO_(2) byproduct formation during photocatalytic NO oxidation.Herein,Bi_(4)Ti_(3)O_(12) nanosheets modified with plasmonic metallic bismuth and abundant oxygen vacancies were synthesized via an in-situ reduction method.The optimized catalyst(BTOR2,with a molar ratio of 40%NaBH_(4) to Bi_(4)Ti_(3)O_(12))achieved a maximum NO removal efficiency of 62.3%,significantly higher than pristine Bi_(4)Ti_(3)O_(12)(40.5%) while minimizing NO_(2) production.The results reveal that the synergistic effects of Bi’s plasmonic resonance and oxygen vacancies enhanced visible light absorption and charge separation.The density functional theory(DFT)analysis showed electrons can transfer from Bi_(4)Ti_(3)O_(12)to Bi,promoting O_(2)activation to·O_(2)^(-)radicals.In-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)confirmed that light-induced H2O adsorption was strengthened,improving·OH radical generation.These radicals promoted the selective conversion of activated NO^(-) to NO_(3)^(-),rather than NO_(2).This work provides valuable insights for advancing research into efficient photocatalysts for air pollution control.展开更多
基金supported by the National Natural Science Foundation of China(Regional Fund)(No.51868054)the Natural Science Foundation of Inner Mongolia of China(General Program)(No.2022MS05052).
文摘4-Nitrophenol(4-NP),a toxic and persistent pollutant in chemical wastewater,presents significant challenges in degradation and mineralization.Conventional ozone oxidation catalysts are hindered by low efficiency,mass transfer constraints and metal leaching,necessitating the development of stable and efficient catalysts.Herein,BCn-H/MS,the derivative of Bi(Ce)-MOF,was prepared by in situ incorporation,thermal decomposition and acid etching.The resulting materials were characterized and employed in catalytic ozonation for the reduction of 4-NP.Under the specific experimental conditions of the O_(3)+BC0.3-H/MS system,the total organic carbon(TOC)and chemical oxygen demand(COD)removal rates of 4-NP were observed to reach 94.6%and 91.8%within 30 min,respectively.These two parameters were improved by raising the initial pH,reducing the pollutant concentration and increasing the catalyst dosage.The abundant oxygen vacancies(OVs)were regarded as the pivotal catalytic site of BC0.3-H/MS,which was conducive to the adsorption of O_(3) and the acceleration of the formation of reactive oxygen species(ROS).The regular hollow square structure effectively boosted the specific surface area,increased OVs exposure and accelerated the adsorption and mass transfer process.The electron paramagnetic resonance(EPR)results demonstrated that the primary ROS engaged in the degradation reaction were⋅OH and⋅O_(2)−.BC0.3-H/MS demonstrated excellent stability and reusability in cyclic experiments.Toxicity analysis revealed that the O_(3)+BC0.3-H/MS system exhibited an effective detoxification effect.Ultimately,the primary degradation pathway of 4-NP was proposed through liquid chromatography-mass spectroscopy(LC-MS)and in-situ diffuse reflectance infrared fourier-transform spectroscopy(DRIFTS)analyses at varying reaction times.
基金supported by the Natural Science Foundation of Chongqing(Nos.CSTB2024NSCQ-MSX1278,CSTB2023NSCQ-MSX0006)Technology Innovation Project of Shapingba District,Chongqing(No.2024004)+2 种基金Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJZD-K202403102,KJQN202103110,KJQN202400512,KJQN202403107)National Natural Science Foundation of China(No.22406014)China Postdoctoral Science Foundation(No.2023MD744137).
文摘The limited redox capability of photocatalysts often leads to harmful NO_(2) byproduct formation during photocatalytic NO oxidation.Herein,Bi_(4)Ti_(3)O_(12) nanosheets modified with plasmonic metallic bismuth and abundant oxygen vacancies were synthesized via an in-situ reduction method.The optimized catalyst(BTOR2,with a molar ratio of 40%NaBH_(4) to Bi_(4)Ti_(3)O_(12))achieved a maximum NO removal efficiency of 62.3%,significantly higher than pristine Bi_(4)Ti_(3)O_(12)(40.5%) while minimizing NO_(2) production.The results reveal that the synergistic effects of Bi’s plasmonic resonance and oxygen vacancies enhanced visible light absorption and charge separation.The density functional theory(DFT)analysis showed electrons can transfer from Bi_(4)Ti_(3)O_(12)to Bi,promoting O_(2)activation to·O_(2)^(-)radicals.In-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)confirmed that light-induced H2O adsorption was strengthened,improving·OH radical generation.These radicals promoted the selective conversion of activated NO^(-) to NO_(3)^(-),rather than NO_(2).This work provides valuable insights for advancing research into efficient photocatalysts for air pollution control.
