Hierarchical tubular MoP/MoS2 composite with enhanced electrochemical hydrogen evolution activity

Abstract

Electrocatalytic production of hydrogen from water is a promising and sustainable strategy. Herein, hierarchical tubular MoP/MoS2 composites with the wall composed of loosely stacked nanosheets were fabricated through partially phosphating the tubular MoS2. As an electrocatayst for hydrogen evolution reaction (HER), the hierarchical tubular MoP/MoS2 composite displayed a superior HER activity with a low overpotential (101 mV) to obtain a current density of 10 mA/cm2, small Tafel slope (56 mV/dec). Moreover, the MoP/MoS2 composite demonstrate superior long-term durability in acid electrolytes. The excellent catalytic activity of MoP/MoS2 composite may be ascribed to its hierarchical structure: hierarchical porous structure can offer mass diffusion pathways, and the nanosheets with MoP/MoS2 heterojunctions can provide rich active sites for HER. Density functional theory (DFT) calculations reveal that more favorable H* adsorption kinetics on the surface of the MoP/MoS2 composite during the HER process than pristine MoP and MoS2. This work can offer a strategy to design high performance electrocatalysts for HER applications.