Combining Highly Dispersed Amorphous MoS3 with Pt Nanodendrites as Robust Electrocatalysts for Hydrogen Evolution Reaction.

Abstract

Surface modification of electrocatalysts to obtain new or improved electrocatalytic performance is currently the main strategy for designing advanced nanocatalysts. In this work, highly dispersed amorphous molybdenum trisulfide-anchored Platinum nanodendrites (denoted as Pt-a-MoS3 NDs) are developed as efficient hydrogen evolution electrocatalysts. The formation mechanism of spontaneous in situ polymerization MoS4 2- into a-MoS3 on Pt surface is discussed in detail. It is verified that the highly dispersed a-MoS3 enhances the electrocatalytic activity of Pt catalysts under both acidic and alkaline conditions. The potentials at the current density of 10mA cm-2 (η10 ) in 0.5msulfuric acid (H2 SO4 ) and 1mpotassium hydroxide (KOH) electrolyte are -11.5 and -16.3mV, respectively, which is significantly lower than that of commercial Pt/C (-20.2mV and -30.7mV). This study demonstrates that such high activity benefits from the interface between highly dispersed a-MoS3 and Pt sites, which act as the preferred adsorption sites for the efficient conversion of hydrion (H+ ) to hydrogen (H2 ). Additionally, the anchoring of highly dispersed clusters to Pt substrate greatly enhances the corresponding electrocatalytic stability.