Ternary CoS2/MoS2/RGO electrocatalyst with CoMoS phase for efficient hydrogen evolution

By Liu, Yan-Ru; Shang, Xiao; Gao, Wen-Kun; Dong, Bin; Chi, Jing-Qi; Li, Xiao; Yan, Kai-Li; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang
Published in Applied Surface Science NULL 2017

Abstract

Abstract CoMoS phase with metallic character plays crucial role on enhancing the activity of MoS2 electrocatalysts for hydrogen evolution reaction (HER). However, only Co atoms located in the edges of MoS2 can create CoMoS phase, so it is a challenge to obtain CoMoS phase with homogeneous distribution limited by the layered MoS2 and doping method of Co. Herein, we reported a simple one-pot hydrothermal method to prepare novel ternary CoS2/MoS2/RGO with CoMoS phase for {HER} using reduced graphene oxide (RGO) as support. {XPS} proves the formation of CoMoS phase, implying the enhanced activity for HER. {RGO} support ensures the well distribution of CoMoS phase and enhances the conductivity of CoS2/MoS2/RGO. Compared to CoS2/RGO, MoS2/RGO and CoS2/MoS2, the obtained CoS2/MoS2/RGO shows superior activity for {HER} with an onset overpotential of ?80 mV (vs. RHE), small Tafel slope of 56 mV dec?1, high exchange current density of 11.4 ?A cm?2 and rigid electrochemical durability. The enhanced performances for {HER} may be ascribed to the formation of CoMoS phase with high activity and the existence of {RGO} support with good electrical conductivitys in ternary CoS2/MoS2/RGO. Therefore, the introduction of CoMoS phase and {RGO} into MoS2 could effectively enhance electrocatalytic properties for HER.

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