Magnetic Cuº/Fe_(3)O_(4)submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)and the degradation of organic pollutants.The...Magnetic Cuº/Fe_(3)O_(4)submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)and the degradation of organic pollutants.The as-prepared magnetic Cu/Fe_(3)O_(4)submicron composites were composed of Cu°and FesO+crystals and had an average size of approximately 220 nm.The Cu/FesO+composites could efficiently catalyze the activation of PMS to generate singlet oxygen,and thusinduced the rapid degradation of rhodamine B,methylene blue,orange 1l,phenol and 4-chlorophenol.The use of 0.1 g/L of the Cu°/Fe_(3)O_(4)composites induced the complete removal of rhodamine B(20μmol/L)in 15 min,methylene blue(20μmol/L)in 5 min,orange II(20μmol/L)in 10 min,phenol(0.1 mmol/L)in 30 min and 4-chlorophenol(0.1 mmol/L)in 15 min with an initial pH value of 7.0 and a PMS concentration of 0.5 mmol/L.The total organic carbon(TOC)removal higher than 85%for all of these five pollutants was obtained in 30 min when the PMS concentration was 2.5 mmol/L.The rate of degradation was considerably higher than that obtained with Cuªor FezO4 particles alone.The enhanced catalytic activity of the Cu°/Fe_(3)O_(4)composites in the activation of PMS was attributed to the synergistic effect of the Cu*and Fe_(3)O_(4)crystals in the composites.Singlet oxygen was identi-fied as the primary reactive oxygen species responsible for pollutant degradation by electron spin resonance and radical quenching experiments.A possible mechanism for the activation of PMS by Cu°/Fe_(3)O_(4)composites is proposed as electron transfer from the organic pollutants to PMS induces the activation of PMS to generate 10z,which induces the degradation of the organic pollutants.As a magnetic catalyst,the Cu°/Fe_(3)O_(4)composites were easily recovered by magnetic separation,and exhibited excellent stability over five successive degradation cycles.The present study provides a facile and green heterogeneous catalysis method for the oxidative removal of organic pollutants.展开更多
Ibuprofen(IBU),a nonsteroidal anti-inflammatory drug,is becoming an important member of pharmaceuticals and personal care products(PPCPs)as emerging pollutants.To degrade IBU,magnetic Fe_3C nanoparticles embedded on N...Ibuprofen(IBU),a nonsteroidal anti-inflammatory drug,is becoming an important member of pharmaceuticals and personal care products(PPCPs)as emerging pollutants.To degrade IBU,magnetic Fe_3C nanoparticles embedded on N-doped carbon(Fe_3C/NC)were prepared as a catalyst by a sol–gel combustion method.As characterized,the Fe_3C/NC nanoparticles were composed of a NC nano-sheet and capsulated Fe_3C particles on the sheet.The Fe_3C/NC nanoparticles were confirmed an efficient catalyst for peroxymonosulfate(PMS)activation to generate sulfate radicals(SO_4^(·-)),single oxygen(~1O_2)and hydroxyl radicals(·OH)toward the degradation of IBU.The added IBU(10 mg/L)was almost completely removed in 30 min by using 0.1 g/L Fe_3C/NC and 2 g/L PMS.The catalyst was confirmed to have good ability and excellent reusability through leaching measurements and cycle experiments.A catalytic mechanism was proposed for the catalytic activation of PMS on Fe_3C/NC,which involves both Fe_3C reactive sites and N-doped carbon matrix as reactive sites in Fe_3C/NC.Moreover,the degradation pathway of IBU in the Fe_3C/NC-PMS system was proposed according to the detections of degradation intermediates.展开更多
文摘Magnetic Cuº/Fe_(3)O_(4)submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)and the degradation of organic pollutants.The as-prepared magnetic Cu/Fe_(3)O_(4)submicron composites were composed of Cu°and FesO+crystals and had an average size of approximately 220 nm.The Cu/FesO+composites could efficiently catalyze the activation of PMS to generate singlet oxygen,and thusinduced the rapid degradation of rhodamine B,methylene blue,orange 1l,phenol and 4-chlorophenol.The use of 0.1 g/L of the Cu°/Fe_(3)O_(4)composites induced the complete removal of rhodamine B(20μmol/L)in 15 min,methylene blue(20μmol/L)in 5 min,orange II(20μmol/L)in 10 min,phenol(0.1 mmol/L)in 30 min and 4-chlorophenol(0.1 mmol/L)in 15 min with an initial pH value of 7.0 and a PMS concentration of 0.5 mmol/L.The total organic carbon(TOC)removal higher than 85%for all of these five pollutants was obtained in 30 min when the PMS concentration was 2.5 mmol/L.The rate of degradation was considerably higher than that obtained with Cuªor FezO4 particles alone.The enhanced catalytic activity of the Cu°/Fe_(3)O_(4)composites in the activation of PMS was attributed to the synergistic effect of the Cu*and Fe_(3)O_(4)crystals in the composites.Singlet oxygen was identi-fied as the primary reactive oxygen species responsible for pollutant degradation by electron spin resonance and radical quenching experiments.A possible mechanism for the activation of PMS by Cu°/Fe_(3)O_(4)composites is proposed as electron transfer from the organic pollutants to PMS induces the activation of PMS to generate 10z,which induces the degradation of the organic pollutants.As a magnetic catalyst,the Cu°/Fe_(3)O_(4)composites were easily recovered by magnetic separation,and exhibited excellent stability over five successive degradation cycles.The present study provides a facile and green heterogeneous catalysis method for the oxidative removal of organic pollutants.
基金supported by the National Natural Science Foundation of China (Nos. 21777194 and 21507168)
文摘Ibuprofen(IBU),a nonsteroidal anti-inflammatory drug,is becoming an important member of pharmaceuticals and personal care products(PPCPs)as emerging pollutants.To degrade IBU,magnetic Fe_3C nanoparticles embedded on N-doped carbon(Fe_3C/NC)were prepared as a catalyst by a sol–gel combustion method.As characterized,the Fe_3C/NC nanoparticles were composed of a NC nano-sheet and capsulated Fe_3C particles on the sheet.The Fe_3C/NC nanoparticles were confirmed an efficient catalyst for peroxymonosulfate(PMS)activation to generate sulfate radicals(SO_4^(·-)),single oxygen(~1O_2)and hydroxyl radicals(·OH)toward the degradation of IBU.The added IBU(10 mg/L)was almost completely removed in 30 min by using 0.1 g/L Fe_3C/NC and 2 g/L PMS.The catalyst was confirmed to have good ability and excellent reusability through leaching measurements and cycle experiments.A catalytic mechanism was proposed for the catalytic activation of PMS on Fe_3C/NC,which involves both Fe_3C reactive sites and N-doped carbon matrix as reactive sites in Fe_3C/NC.Moreover,the degradation pathway of IBU in the Fe_3C/NC-PMS system was proposed according to the detections of degradation intermediates.
