Designing electrocatalysts for HER in alkaline conditions to overcome the sluggish kinetics associated with the additional water dissociation step is a recognized challenge in promoting the hydrogen econ-omy.To this end,delicately tuning the atomic-scale structure and surface composition of nanoparticles is a common strategy and,specifically,making use of hybrid structures,can produce synergistic effects that lead to highly active catalysts.Here,we present a core-shell catalyst of Ag@MoS2 that shows promis-ing results towards the hydrogen evolution reaction(HER)in both 0.5 M H2SO4 and 0.5 M KOH.In this hybrid structure,the MoS2 shell is strained and defective,and charge transfer occurs between the con-ductive core and the shell,contributing to the electrocatalytic activity.The shelling process results in a large fraction of Ag2S in the cores,and adjusting the relative fractions of Ag,Ag2S,and MoS2 leads to improved catalytic activity and fast charge-transfer kinetics.We suggest that the enhancement of alka-line HER is associated with a cooperative effect of the interfaces,where the Ag(l)sites in Ag2S drive the water dissociation step,and the formed hydrogen subsequently recombines on the defective MoS2 shell.This study demonstrates the benefits of hybrid structures as functional nanomaterials and provides a scheme to activate MoS2 for HER in alkaline conditions.

Avraham Bar-Hen;Simon Hettler;Ashwin Ramasubramaniam;Raul Arenal;Ronen Bar-Ziv;Maya Bar Sadan

Department of Chemistry,Ben-Gurion University of the Negev,Beer-Sheva 8410501,Israel;Department of Chemistry,Nuclear Research Center Negev,P.O.Box 9001,Beer-Sheva 84190,Israel;Laboratorio de Microscopías Avanzadas,Universidad de Zaragoza,50018 Zaragoza,Spain;Instituto de Nanociencia y Materiales de Aragon,CSIC-U.de Zaragoza,Calle Pedro Cerbuna 12,50009 Zaragoza,Spain;Department of Mechanical and Industrial Engineering,University of Massachusetts,Amherst,MA 01003,United States;ARAID Foundation,50018 Zaragoza,Spain

能源化学

[1]Avraham Bar-Hen;Simon Hettler;Ashwin Ramasubramaniam;Raul Arenal;Ronen Bar-Ziv;Maya Bar Sadan-.Catalysts for the hydrogen evolution reaction in alkaline medium:Configuring a cooperative mechanism at the Ag-Ag2S-MoS2 interface)[J].能源化学,2022(11):481-488

Configuring,shelling,recombines

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