Self-supported CoMoS4 nanosheet array as an efficient catalyst for hydrogen evolution reaction at neutral pH

摘要

Development of earth-abundant electrocatalysts,particularly for high-efficiency hydrogen evolution reaction (HER) under benign conditions,is highly desired,but still remains a serious challenge.Herein,we report a high-performance amorphous CoMoS4 nanosheet array on carbon cloth (CoMoS4 NS/CC),prepared by hydrothermal treatment of a Co(OH)F nanosheet array on a carbon cloth (Co(OH）F NS/CC) in (NH4)2MoS4 solution.As a three-dimensional HER electrode,CoMoS4 NS/CC exhibits remarkable activity in 1.0 M phosphate buffer saline (pH 7),only requiring an overpotential of 183 mV to drive a geometrical current density of 10 mA.cm-2.This overpotential is 140 mV lower than that for Co(OH)F NS/CC.Notably this electrode also shows outstanding electrochemical durability and nearly 100％ Faradaic efficiency.Density functional theory calculations suggest that CoMoS4 has a more favorable hydrogen adsorption free energy than Co(OH)F.