摘要
Lack of high-efficiency,cost-efficient,and well-stocked oxygen evolution reaction(OER)electrocatalysts is a main challenge in large-scale implementation of electrolytic water.By regulating the electronic structure of isolated single-atom metal sites,highperformance transition-metal-based catalysts can be fabricated to greatly improve the OER performance.Herein,we demonstrate single-atom manganese coordinated to nitrogen and sulfur species in two-dimensional graphene nanosheets MnNSG(NSG means N-and S-codoped graphene)as an active and durable OER catalyst with a low overpotential of 296 mV in alkaline media,compared to that of the benchmark IrO_(2) catalyst.Theoretical calculations and experimental measurements reveal that the Mn-N3S sites in the graphene matrix are the most active sites for the OER due to modified electronic structure of the Mn site by three nitrogen and one sulfur atoms coordination,which show lower theoretical overpotential than the Mn-N4 sites and over which the O–O formation step is the rate-determining step.
基金
supported by the National Natural Science Foundation of China(Nos.22075099 and 31971322)
the Education Department of Jilin Province(JJKH20220967KJ)
the National Basic Research Program of China(Nos.2016YFA0203200 and 2020YFA0710702)
CAS President’s International Fellowship Initiative(PIFI,2021PM0059)
the State Key Laboratory of Natural and Biomimetic Drugs,Peking University.