Monotonic pore size and particles inseparability of metal-organic frameworks(MOFs)caused serious effects on its light absorption ability and charge separation,restricting its application for antibiotic such as levoflo...Monotonic pore size and particles inseparability of metal-organic frameworks(MOFs)caused serious effects on its light absorption ability and charge separation,restricting its application for antibiotic such as levofloxacin(LEV)degradation in water.In this study,a magnetically detachable nano-photocatalyst(ZnFe_(2)O_(4)@MIL-88A(Fe))was synthesized using a simple two-step hydrothermal technique.The morphology and microstructure analyses showed that n-type ZnFe_(2)O_(4)catalyst particleswere efficiently assembled onto the surface of MIL-88A(Fe)crystal.Photocatalytic activity studies indicated that the ZnFe_(2)O_(4)@MIL-88A(Fe)plus H_(2)O_(2)exhibiting a significantly boosted photo-Fenton activity toward LEV at visible light irradiation,compared to the pure ZnFe_(2)O_(4)and MIL-88A(Fe),the degradation efficiency accordingly reached up to nearly 82%and 25%within 60 min.This excellent photocatalytic performance was ascribed to the synergistic effects of the heterogeneous structure of ZnFe_(2)O_(4)and MIL-88A(Fe),whereby the efficient separation of charge carriers in the catalytic system is mutually reinforced with the efficient reduction of Fe^(3+)and Fe^(2+).Meanwhile,the degradationmechanism and intermediates of LEV during the photo-Fenton reaction process were also studied in depth through free radical burst,electron paramagnetic resonance,and mass spectrometry analyses,etc.Additionally,the ZnFe_(2)O_(4)@MIL-88A(Fe)composite catalyst displayed significant stability and ease of separation,indicating potential for the photooxidative degradation of organic pollutants.展开更多
A low cycle of Fe^(2+)/Fe^(3+),additional H_(2)O_(2)use,and low mineralization efficiency have limited the wide application of Fe-MOFs.Herein,a novel Z-scheme r-MIL-88A/OV-BiOBr composites(OV-BM)with oxygen vacancies(...A low cycle of Fe^(2+)/Fe^(3+),additional H_(2)O_(2)use,and low mineralization efficiency have limited the wide application of Fe-MOFs.Herein,a novel Z-scheme r-MIL-88A/OV-BiOBr composites(OV-BM)with oxygen vacancies(OV)were fabricated by polyvinylpyrrolidone/ethylene glycol solvothermal method.The optimal OV-BM-25 showed the highest degradation efficiency of 97.8%for chloroquine phosphate(CQ)by initiat-ing H_(2)O_(2)under LED visible light irradiation within 60 min.The presence of oxygen vacancies enhanced the electron/hole separation in OV-BM composites and the electron transfer from OV-BiOBr to r-MIL-88A,driving Fe^(2+)/Fe^(3+)cycling and in-situ H_(2)O_(2)generation.Quenching experiments and EPR analysis demon-strated that O 2-,1 O 2,and e-were the main active species,inducing deamination,decarbonization,and cleavage of ring structures in CQ.The possible decomposition pathways of CQ and the ecotoxicity of in-termediates were evaluated through UPLC-MS and QSAR analysis.This study provides a theoretical basis for developing Fe-MOFs-based heterojunctions photocatalysts in a Z-scheme photo-Fenton system to treat CQ-bearing organic wastewater.展开更多
随着新型冠状病毒肺炎(COVID-19)在全球的流行,主要成分为苯扎氯铵的消毒剂大量使用对环境带来威胁.本研究通过水热法成功制备了铁基金属有机骨架MIL-88A,将其作为光催化剂成功实现了苯扎氯铵在可见光下的高效降解.通过SEM、XRD、XPS以...随着新型冠状病毒肺炎(COVID-19)在全球的流行,主要成分为苯扎氯铵的消毒剂大量使用对环境带来威胁.本研究通过水热法成功制备了铁基金属有机骨架MIL-88A,将其作为光催化剂成功实现了苯扎氯铵在可见光下的高效降解.通过SEM、XRD、XPS以及UV-visDRS等表征方法研究了MIL-88A的形貌、结构以及光催化性能.为了达到光催化降解苯扎氯铵的最佳效率,探究了MIL-88A在不同条件下的光催化降解性能.结果表明,MIL-88A在pH=5,H2O2投加量为0.9 mL·L^(-1),MIL-88A剂量为0.25 g·L^(-1)时,降解效果最好,35 min DDBAC降解效率达到100%.采用UHPLC-Q-TOF-MS确定了降解中间产物,分析了苯扎氯铵可能的降解途径.此外,基于分子轨道理论和自由基淬灭实验证明了氧化降解苯扎氯铵过程中羟基自由基是主要贡献者.通过发光细菌法对DDBAC及其中间体的毒性进行了评估,结果表明,MIL-88A可见光光芬顿工艺能够实现溶液脱毒.光催化降解循环实验以及对催化剂反应前后的表征证明了MIL-88A具有较高的稳定性.展开更多
MIL-88A(Fe)@sponge(MS) was synthesized by a dip-coating method, which displayed efficient photocatalytic Cr(Ⅵ) reduction efficiency under both low power LED UV light and real solar light irradiation. It was observed ...MIL-88A(Fe)@sponge(MS) was synthesized by a dip-coating method, which displayed efficient photocatalytic Cr(Ⅵ) reduction efficiency under both low power LED UV light and real solar light irradiation. It was observed that MS(0.2 g/L) could remove 100% Cr(Ⅵ)(10 mg/L) by adding 0.4 mmol/L tartaric acid(TA) without adjusting pH(pH 5.05) within 6.0 min and 3.0 min under UV light and real solar light irradiation, respectively. Besides, the photo-induced e-and radicals(O_(2)^(·-) and CO_(2)^(·-)) were found to play the momentous roles in the MS/TA/UVL/Cr(Ⅵ) system by the scavenger experiments and electron spin resonance(ESR) tests. MS was also filled into a fixed-bed reactor to test the possibility of long-term Cr(Ⅵ)reduction operation in TA/UVL system. As expected, the results revealed that MS could still maintain 100% activity up to 60 h. These results demonstrated that MIL-88A(Fe) might be the potentially efficient catalyst for large-scale wastewater treatment in the near future.展开更多
基金supported by the National Natural Science Foundation of China(No.22178325)Jinhua Science and Technology Plan Project.
文摘Monotonic pore size and particles inseparability of metal-organic frameworks(MOFs)caused serious effects on its light absorption ability and charge separation,restricting its application for antibiotic such as levofloxacin(LEV)degradation in water.In this study,a magnetically detachable nano-photocatalyst(ZnFe_(2)O_(4)@MIL-88A(Fe))was synthesized using a simple two-step hydrothermal technique.The morphology and microstructure analyses showed that n-type ZnFe_(2)O_(4)catalyst particleswere efficiently assembled onto the surface of MIL-88A(Fe)crystal.Photocatalytic activity studies indicated that the ZnFe_(2)O_(4)@MIL-88A(Fe)plus H_(2)O_(2)exhibiting a significantly boosted photo-Fenton activity toward LEV at visible light irradiation,compared to the pure ZnFe_(2)O_(4)and MIL-88A(Fe),the degradation efficiency accordingly reached up to nearly 82%and 25%within 60 min.This excellent photocatalytic performance was ascribed to the synergistic effects of the heterogeneous structure of ZnFe_(2)O_(4)and MIL-88A(Fe),whereby the efficient separation of charge carriers in the catalytic system is mutually reinforced with the efficient reduction of Fe^(3+)and Fe^(2+).Meanwhile,the degradationmechanism and intermediates of LEV during the photo-Fenton reaction process were also studied in depth through free radical burst,electron paramagnetic resonance,and mass spectrometry analyses,etc.Additionally,the ZnFe_(2)O_(4)@MIL-88A(Fe)composite catalyst displayed significant stability and ease of separation,indicating potential for the photooxidative degradation of organic pollutants.
基金sponsored by the Science&Technology Innovation Action Plan of Shanghai(Nos.20230742100 and 21230714000)the Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste.
文摘A low cycle of Fe^(2+)/Fe^(3+),additional H_(2)O_(2)use,and low mineralization efficiency have limited the wide application of Fe-MOFs.Herein,a novel Z-scheme r-MIL-88A/OV-BiOBr composites(OV-BM)with oxygen vacancies(OV)were fabricated by polyvinylpyrrolidone/ethylene glycol solvothermal method.The optimal OV-BM-25 showed the highest degradation efficiency of 97.8%for chloroquine phosphate(CQ)by initiat-ing H_(2)O_(2)under LED visible light irradiation within 60 min.The presence of oxygen vacancies enhanced the electron/hole separation in OV-BM composites and the electron transfer from OV-BiOBr to r-MIL-88A,driving Fe^(2+)/Fe^(3+)cycling and in-situ H_(2)O_(2)generation.Quenching experiments and EPR analysis demon-strated that O 2-,1 O 2,and e-were the main active species,inducing deamination,decarbonization,and cleavage of ring structures in CQ.The possible decomposition pathways of CQ and the ecotoxicity of in-termediates were evaluated through UPLC-MS and QSAR analysis.This study provides a theoretical basis for developing Fe-MOFs-based heterojunctions photocatalysts in a Z-scheme photo-Fenton system to treat CQ-bearing organic wastewater.
文摘随着新型冠状病毒肺炎(COVID-19)在全球的流行,主要成分为苯扎氯铵的消毒剂大量使用对环境带来威胁.本研究通过水热法成功制备了铁基金属有机骨架MIL-88A,将其作为光催化剂成功实现了苯扎氯铵在可见光下的高效降解.通过SEM、XRD、XPS以及UV-visDRS等表征方法研究了MIL-88A的形貌、结构以及光催化性能.为了达到光催化降解苯扎氯铵的最佳效率,探究了MIL-88A在不同条件下的光催化降解性能.结果表明,MIL-88A在pH=5,H2O2投加量为0.9 mL·L^(-1),MIL-88A剂量为0.25 g·L^(-1)时,降解效果最好,35 min DDBAC降解效率达到100%.采用UHPLC-Q-TOF-MS确定了降解中间产物,分析了苯扎氯铵可能的降解途径.此外,基于分子轨道理论和自由基淬灭实验证明了氧化降解苯扎氯铵过程中羟基自由基是主要贡献者.通过发光细菌法对DDBAC及其中间体的毒性进行了评估,结果表明,MIL-88A可见光光芬顿工艺能够实现溶液脱毒.光催化降解循环实验以及对催化剂反应前后的表征证明了MIL-88A具有较高的稳定性.
基金supported by National Natural Science Foundation of China (Nos. 22176012, 51878023)Beijing Natural Science Foundation (No. 8202016)+1 种基金Beijing Talent Project (No. 2020A27)BUCEA Doctor Graduate Scientific Research Ability Improvement Project (No. DG2021004)。
文摘MIL-88A(Fe)@sponge(MS) was synthesized by a dip-coating method, which displayed efficient photocatalytic Cr(Ⅵ) reduction efficiency under both low power LED UV light and real solar light irradiation. It was observed that MS(0.2 g/L) could remove 100% Cr(Ⅵ)(10 mg/L) by adding 0.4 mmol/L tartaric acid(TA) without adjusting pH(pH 5.05) within 6.0 min and 3.0 min under UV light and real solar light irradiation, respectively. Besides, the photo-induced e-and radicals(O_(2)^(·-) and CO_(2)^(·-)) were found to play the momentous roles in the MS/TA/UVL/Cr(Ⅵ) system by the scavenger experiments and electron spin resonance(ESR) tests. MS was also filled into a fixed-bed reactor to test the possibility of long-term Cr(Ⅵ)reduction operation in TA/UVL system. As expected, the results revealed that MS could still maintain 100% activity up to 60 h. These results demonstrated that MIL-88A(Fe) might be the potentially efficient catalyst for large-scale wastewater treatment in the near future.
