Formic acid is considered one of the most economically viable products for electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,developing highly active and selective electrocatalysts for effective CO_(2)conver...Formic acid is considered one of the most economically viable products for electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,developing highly active and selective electrocatalysts for effective CO_(2)conversion remains a grand challenge.Herein,we report that structural modulation of the bismuth oxide nanosheet via Zn^(2+)cooperation has a profound positive effect on exposure of the active plane,thereby contributing to high electrocatalytic CO_(2)RR performance.The obtained Zn-Bi_(2)O_(3)catalyst demonstrates superior selectivity towards formate generation in a wide potential range;a high Faradaic efficiency of 95%and a desirable partial current density of around 20 mA·cm^(-2)are obtained at−0.9 V(vs.reversible hydrogen electrode(RHE)).As proposed by density functional theory calculations,Zn substitution is the most energetically feasible for forming and stabilizing the key OCHO*intermediate among the used metal ions.Moreover,the more negative adsorption energy of OCHO*and the relatively low energy barrier for the desorption of HCOOH*are responsible for the enhanced activity and selectivity.展开更多
Layered metal dichalcogenides(MX_(2))constructed from 2D covalently bonded monolayers are an exciting family as promising low-cost electrocatalysts towards the hydrogen evolution reaction(HER).Defect engineering of la...Layered metal dichalcogenides(MX_(2))constructed from 2D covalently bonded monolayers are an exciting family as promising low-cost electrocatalysts towards the hydrogen evolution reaction(HER).Defect engineering of layered lattices to fully utilize MX_(2)nanosheets is highly desirable.Herein,we report a universal synthesis of defective MX_(2)nanosheets by modulating both the basal planes and the interlayers.A series of basal plane-disordered and interlayer-expanded MX_(2)(M=Mo,W,Sn;X=S,Se)nanosheets are synthesized.Interlayer spacings of the MX_(2)nanosheets are significantly enlarged to 0.93-1.05 nm with an increase of 0.34-0.40 nm,owing to species intercalation.Abundant defects resulting from the wide interlayer expansion and the disordered basal planes offer extensive unsaturated chalcogen atoms as active sites for HER.Consequently,interlayer-expanded and defect-rich(IEDR)MX_(2)catalysts exhibit striking activities,delivering small Tafel slopes,low onset overpotentials,large cathodic current densities and excellent long-term stabilities.Our work paves a new pathway to improve the electrocatalytic HER activity by defect modulation.展开更多
基金supported by the Singapore Ministry of Education Academic Research Fund Tier 1(Nos.RG 85/20 and 125/21)the National Natural Science Foundation of China(No.U20A200201)+1 种基金China Postdoctoral Science Fund,No.3 Special Funding(Pre-Station)(No.2021TQ007)natural science program on basic research project of Shaanxi province(No.2023-JC-QN-0155).
文摘Formic acid is considered one of the most economically viable products for electrocatalytic CO_(2)reduction reaction(CO_(2)RR).However,developing highly active and selective electrocatalysts for effective CO_(2)conversion remains a grand challenge.Herein,we report that structural modulation of the bismuth oxide nanosheet via Zn^(2+)cooperation has a profound positive effect on exposure of the active plane,thereby contributing to high electrocatalytic CO_(2)RR performance.The obtained Zn-Bi_(2)O_(3)catalyst demonstrates superior selectivity towards formate generation in a wide potential range;a high Faradaic efficiency of 95%and a desirable partial current density of around 20 mA·cm^(-2)are obtained at−0.9 V(vs.reversible hydrogen electrode(RHE)).As proposed by density functional theory calculations,Zn substitution is the most energetically feasible for forming and stabilizing the key OCHO*intermediate among the used metal ions.Moreover,the more negative adsorption energy of OCHO*and the relatively low energy barrier for the desorption of HCOOH*are responsible for the enhanced activity and selectivity.
基金National Natural Science Foundation of China(No.51802145)Fundamental Research Funds for the Central Universities(No.PA2018GDQT0009)Natural Science Foundation of Guangdong Province(No.2018A030310225)。
文摘Layered metal dichalcogenides(MX_(2))constructed from 2D covalently bonded monolayers are an exciting family as promising low-cost electrocatalysts towards the hydrogen evolution reaction(HER).Defect engineering of layered lattices to fully utilize MX_(2)nanosheets is highly desirable.Herein,we report a universal synthesis of defective MX_(2)nanosheets by modulating both the basal planes and the interlayers.A series of basal plane-disordered and interlayer-expanded MX_(2)(M=Mo,W,Sn;X=S,Se)nanosheets are synthesized.Interlayer spacings of the MX_(2)nanosheets are significantly enlarged to 0.93-1.05 nm with an increase of 0.34-0.40 nm,owing to species intercalation.Abundant defects resulting from the wide interlayer expansion and the disordered basal planes offer extensive unsaturated chalcogen atoms as active sites for HER.Consequently,interlayer-expanded and defect-rich(IEDR)MX_(2)catalysts exhibit striking activities,delivering small Tafel slopes,low onset overpotentials,large cathodic current densities and excellent long-term stabilities.Our work paves a new pathway to improve the electrocatalytic HER activity by defect modulation.
