Large-scale Two-dimensional MoSx Catalyst Prepared under Mild Conditions for Enhancing Electrocatalytic Hydrogen Evolution Reaction.

Abstract

As an electrocatalyst with abundant resources and great potential, molybdenum disulfide is regarded as one of the most likely alternatives to expensive noble-metals catalysts. However, it is still a challenge to achieve large scale production of few-layer MoS2 with enhancing activity of electrocatalytic hydrogen reaction at ambient conditions. Herein, we developed a simple environmentally friendly two-step method, which included intercalation reaction and a subsequent electrochemical reduction reaction for mass preparation of defect-rich desulfurized MoSx (D-MoSx ) nanosheets with plentiful sulfur vacancies. The ratio of sulfur-molybdenum atoms can be adjusted from 2 : 1 to 1.4 : 1 by regulating the desulfurization voltage. It was found that the HER catalytic activity of the D-MoSx was enhanced compared with that of pristine MoS2 (P-MoS2 ), the current density of D-MoSx (desulfurization at -1.0 V) at -0.3 V versus RHE was about 169% of the P-MoS2 , and the Tafel slope decreased to 136 mV dec-1 . This method can be widely applied to large-scale preparation of other two-dimensional materials.