The development of novel nanozymes for environmental contamination remediation is a worthwhile research direction.However,most of the reported nanozymes cannot degrade efficiently due to the limitation of the internal...The development of novel nanozymes for environmental contamination remediation is a worthwhile research direction.However,most of the reported nanozymes cannot degrade efficiently due to the limitation of the internal active sites not being able to come into direct contact with contaminants.Therefore,we reported Fe-N-C single-atom nanozymes(SAzymes)with atomically dispersed FeN4 active sites anchored on a three-dimensional hierarchically ordered microporous-mesoporous-macroporous nitrogen doped carbon matrix(3DOM Fe-N-C)for the degradation of a targeted environmental pollutant(rhodamine B(RhB)).The three-dimensional(3D)hierarchically ordered porous structure may accelerate mass transfer and improve the accessibility of active sites.This structure and high metal atom utilization endow Fe-N-C SAzyme with enhanced tri-enzyme-mimic activities,comprising oxidase-mimic,peroxidase-mimic,and catalase-mimic activities.Based on its excellent peroxidase-mimic activity,3DOM Fe-N-C can degrade RhB by hydroxyl radicals(·OH)generated in the presence of hydrogen peroxide.This study provides a new idea for designing porous Fe-N-C SAzymes for environmental contamination remediation.展开更多
Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contam...Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contaminants(EOCs)by activating peroxymonosulfate(PMS).However,the construction of atomically dispersed catalysts with diatomic/multiatomic metal active sites by activating PMS to degrade pollutants is still seldom reported,despite the unique merits of atom-pair in synergistic electronic modulation and breaking stubborn restriction of scaling relations on catalytic activity.We have synthesized Fe1-N-C,Fe_(2)-N-C,and Fe_(3)-N-C catalysts with monoatomic iron,diatomic iron,and triatomic iron active center,respectively.The results show that the catalytic degradation activity of Fe_(2)-N-C is twice that of Fe1-N-C and Fe_(3)-N-C due to its unique Fe_(2)N6 coordination structure,which fulfilled the complete degradation of rhodamine B(RhB),bisphenol A(BPA),and 2,4-dichlorophenol(2,4-DP)within 2 min.Electron paramagnetic resonance(EPR)and radical quenching experiments confirmed that the reaction was a nonradical reaction on the catalyst surface.And singlet oxygen and Fe(IV)are the key active species.展开更多
基金We are grateful for the support from the Ministry of Science and Technology of China(Nos.2016YFA0203203 and 2019YFA0709202)the National Natural Science Foundation of China(No.22074137).
文摘The development of novel nanozymes for environmental contamination remediation is a worthwhile research direction.However,most of the reported nanozymes cannot degrade efficiently due to the limitation of the internal active sites not being able to come into direct contact with contaminants.Therefore,we reported Fe-N-C single-atom nanozymes(SAzymes)with atomically dispersed FeN4 active sites anchored on a three-dimensional hierarchically ordered microporous-mesoporous-macroporous nitrogen doped carbon matrix(3DOM Fe-N-C)for the degradation of a targeted environmental pollutant(rhodamine B(RhB)).The three-dimensional(3D)hierarchically ordered porous structure may accelerate mass transfer and improve the accessibility of active sites.This structure and high metal atom utilization endow Fe-N-C SAzyme with enhanced tri-enzyme-mimic activities,comprising oxidase-mimic,peroxidase-mimic,and catalase-mimic activities.Based on its excellent peroxidase-mimic activity,3DOM Fe-N-C can degrade RhB by hydroxyl radicals(·OH)generated in the presence of hydrogen peroxide.This study provides a new idea for designing porous Fe-N-C SAzymes for environmental contamination remediation.
基金supported by the National Natural Science Foundation of China(Nos.22074137 and 21721003)the Ministry of Science and Technology of China(No.2016YFA0203203).
文摘Atomically dispersed catalysts have been widely studied due to their high catalytic activity and atom utilization.Single-atom catalysts have achieved breakthrough progress in the degradation of emerging organic contaminants(EOCs)by activating peroxymonosulfate(PMS).However,the construction of atomically dispersed catalysts with diatomic/multiatomic metal active sites by activating PMS to degrade pollutants is still seldom reported,despite the unique merits of atom-pair in synergistic electronic modulation and breaking stubborn restriction of scaling relations on catalytic activity.We have synthesized Fe1-N-C,Fe_(2)-N-C,and Fe_(3)-N-C catalysts with monoatomic iron,diatomic iron,and triatomic iron active center,respectively.The results show that the catalytic degradation activity of Fe_(2)-N-C is twice that of Fe1-N-C and Fe_(3)-N-C due to its unique Fe_(2)N6 coordination structure,which fulfilled the complete degradation of rhodamine B(RhB),bisphenol A(BPA),and 2,4-dichlorophenol(2,4-DP)within 2 min.Electron paramagnetic resonance(EPR)and radical quenching experiments confirmed that the reaction was a nonradical reaction on the catalyst surface.And singlet oxygen and Fe(IV)are the key active species.
