(Invited) Texturization of MoS2 Surface to Enhance Catalytic Property of Hydrogen Evolution Reaction

Abstract

Molybdenum disulfide (MoS2) has been gathered attention as a non-precious metal catalyst for hydrogen evolution reaction (HER); however, pristine MoS2 (bulk mineral) is known to be a poor catalyst. The fundamental challenge to improving the catalytic performance of MoS2 is to increase the density of active reaction sites on the surface of MoS2. Usually, the crystalline plane (0001) is inert to the HER whereas the edges of MoS2 are active. In this presentation, we will show how our thermal texturization method improves the HER performance of MoS2 using a simple annealing procedure in forming gas (hydrogen and nitrogen mixture). The annealed bulk MoS2 shows a roughened surface including a higher density of edge sites. As a result, the catalytic performance of the annealed MoS2 shows more 100 mV reduction of overpotential to obtain 10 mA/cm2 of HER current density. We show that this treatment is generally applicable to many morphologies, including bulk, microflake, and nanoflakes of MoS2 to use as an efficient HER catalyst. The simplicity of this procedure suggests this method would be scalable, and furthermore could be applicable for other chalcogenide-based 2D materials.