摘要
This study innovated cobalt-based catalytic nanocomposites(CCNs)for the heterogeneous activation of peracetic acid(PAA),a green and efficient advanced oxidation process for removing antibiotics from water.Commercial Co_(3)O_(4) catalysts exhibit limited activity due to stable electronic structures.To overcome this,CCNs were synthesized using a one-step condensation method,incorporating a size control strategy that anchors Co_(3)O_(4) nanoclusters within 4‒5 nm onto six-fold cavity of g-C3N4,simultaneously modifying the coordination environment of Co.This alteration significantly enhances the adsorption energy of PAA and catalytic activity compared to commercial Co_(3)O_(4).The improved performance of CCN2,in particular,is attributed to a shift in the cobalt d band center towards the Fermi level,facilitating electron delocalization and transfer,enhancing Co‒O bonding,and accelerating PAA decomposition.CCN2’s superior activity,with a cefapirin(CFP)degradation kinetic rate constant(k1=0.760 min^(−1))~11 times that of PAA direct oxidation(k1=0.070 min^(−1))and~5 times that of commercial Co_(3)O_(4)/PAA system(k1=0.164 min^(−1)),is due to its ability to generate dominant reactive species for antibiotic degradation,including alkoxy radicals(CH3C(=O)OO•),high valence metal(Co^(Ⅳ)(=O)^(2+)),and singlet oxygen(^(1)O_(2)),with the latter two being crucial for the degradation process.The degradation of CFP involved three mechanisms,including direct oxidation by PAA,decarboxylation,and open-ring reactions at nitrogen sites.This research provides insights into developing high-activity catalysts for efficient PAA activation and antibiotic removal,leveraging the strategy of shifting the transition metal d band center.
基金
supported by the National Key Research and Development Program of China (Grant Nos. 2021YFE010080, 2021YFA1202500, and 2023YFC3209600)
the National Natural Science Foundation of China (NSFC) (Grant Nos. 52200083 and 52270053)
Beijing Natural Science Foundation (Grant No. 8232035)
Beijing Nova Program (Grant No. 20220484215)
Beijing National Laboratory for Molecular Sciences (Grant No. BNLMS2023011)
the Emerging Engineering Interdisciplinary-Young Scholars Project (Peking University)
Horizontal Scientific Research Funds of Taiyuan University of Technology (Grant No. RH2300002821)
the Science and Technology Projects of Shanxi Transportation Holdings Group Co., Ltd. (Grant No. 2022-JKKJ-8)
the Fundamental Research Funds for the Central Universities
supported by the High-Performance Computing Platform of Peking University