Fabrication of 3D ordered mesoporous MoS2/C composite with few-layered MoS2 for electrochemical hydrogen evolution

Abstract

MoS2 is a highly active catalyst for hydrogen evolution reaction (HER), but its active site for HER is limited to the edges. Thus structures exposing plenty of edges is desired for MoS2 to apply in HER. Porous three-dimensional (3D) structure full of few-layered MoS2 satisfies the requirement. In this work, a 3D ordered mesoporous structure MoS2/C composite with few-layered MoS2 was synthesized by liquid phase nanocasting method, using SBA-15 as hard template, sucrose as carbon source and ammonium tetrathiomolybdate (ATTM) as MoS2 precursor. The limiting effect of amorphous carbon makes thin MoS2 slices evenly dispersed, and avoids occurrence of MoS2 agglomeration, resulting in the exposure of a large number of MoS2 edges as active sites. The 3D ordered mesoporous structure of the catalyst provides high specific surface areas and ensures transport channels for material and electron for electrochemical HER. As a result, the composite demonstrates efficient HER activity with an overpotential of 165 mV at current density of 10 mA/cm2, and a Tafel slope of 91 mV under acidic conditions. This study provides a basis for constructing 3D HER catalyst with high specific surface area and few-layered MoS2 uniformly dispersed.