Constructing atomically dispersed active sites with densely exposed and dispersed double metal-Sx catalytic sites for favorable OER catalytic activity remains rare and challenging.Herein,we design and construct a Fe_(...Constructing atomically dispersed active sites with densely exposed and dispersed double metal-Sx catalytic sites for favorable OER catalytic activity remains rare and challenging.Herein,we design and construct a Fe_(1)S_(x)@Co_(3)S_(4) electrocatalyst with Fe single atoms epitaxially confined in Co_(3)S_(4) nanosheets for catalyzing the sluggish alkaline oxygen evolution reaction(OER).Consequently,in ultralow concentration alkaline solutions(0.1 mol/L KOH),such a catalyst is highly active and robust for OER with low overpotentials of 300 and 333 mV at current densities of 10 and 30 mA/cm^(2),respectively,accompanying long-term stability without significant degradation even for 350 h.In addition,Fe_(1)S_(x)@Co_(3)S_(4) shows a turnover frequency(TOF)value of 0.18 s−1,nearly three times that of Co_(3)S_(4)(0.07 s−1),suggesting the higher atomic utilization of Fe single atoms.Mössbauer and in-situ Raman spectra confirm that the OER activity of Fe_(1)S_(x)@Co_(3)S_(4) origins from a thin catalytic layer of Co(Fe)OOH that interacts with trace-level Fe species in the electrolyte,creating dynamically stable active sites.Combined with experimental characterizations,it suggests that the most active S-coordinated dual-metal site configurations are 2S-bridged(Fe-Co)S4,in which Co-S and Fe-S moieties are shared with two S atoms,which can strongly regulate the adsorption energy of reaction intermediates,accelerating the OER reaction kinetics.展开更多
基金National Natural Science Foundation of China(Nos.21501096,22075223)Natural Science Foundation of Jiangsu Province,China(Nos.BK20150086,BK20201120)+4 种基金Foundation of the Jiangsu Education Committee,China(No.15KJB150020)Six Talent Peaks Project in Jiangsu Province,China(No.JY-087)Innovation Project of Jiangsu Province,Excellent Scientific and Technological Innovation Team of Colleges and Universities of Jiangsu Province,China(No.SUJIAOKE 2021 No.1)Key Subject of Ecology of Jiangsu Province,China(No.SUJIAOYANHAN 2022 No.2)Project of the Scientific and Technological Innovation Team of Nanjing,China(No.NINGJIAOGAOSHI 2021 No.16).
文摘Constructing atomically dispersed active sites with densely exposed and dispersed double metal-Sx catalytic sites for favorable OER catalytic activity remains rare and challenging.Herein,we design and construct a Fe_(1)S_(x)@Co_(3)S_(4) electrocatalyst with Fe single atoms epitaxially confined in Co_(3)S_(4) nanosheets for catalyzing the sluggish alkaline oxygen evolution reaction(OER).Consequently,in ultralow concentration alkaline solutions(0.1 mol/L KOH),such a catalyst is highly active and robust for OER with low overpotentials of 300 and 333 mV at current densities of 10 and 30 mA/cm^(2),respectively,accompanying long-term stability without significant degradation even for 350 h.In addition,Fe_(1)S_(x)@Co_(3)S_(4) shows a turnover frequency(TOF)value of 0.18 s−1,nearly three times that of Co_(3)S_(4)(0.07 s−1),suggesting the higher atomic utilization of Fe single atoms.Mössbauer and in-situ Raman spectra confirm that the OER activity of Fe_(1)S_(x)@Co_(3)S_(4) origins from a thin catalytic layer of Co(Fe)OOH that interacts with trace-level Fe species in the electrolyte,creating dynamically stable active sites.Combined with experimental characterizations,it suggests that the most active S-coordinated dual-metal site configurations are 2S-bridged(Fe-Co)S4,in which Co-S and Fe-S moieties are shared with two S atoms,which can strongly regulate the adsorption energy of reaction intermediates,accelerating the OER reaction kinetics.
