Molybdenum disulfide and Au ultrasmall nanohybrids as highly active electrocatalysts for hydrogen evolution reaction

Abstract

Molybdenum disulfide (MoS₂) is a promising catalyst for hydrogen generation from water splitting. However, there is still a gap compared to electrocatalytic performance of Pt group metals. Herein, we propose a simple solvothermal method to prepare ultrasmall MoS₂–Au nanohybrids with average diameters of 2.5 nm. The MoS₂–Au nanohybrids exhibit superior HER performance with a low onset potential of 17 mV, a Tafel slope of 40 mV dec⁻¹ and a current density of 10 mA cm⁻² at an overpotential of only 66 mV. The enhanced HER catalytic activity is attributed to the doping of gold resulting in a synergistic effect between Au and MoS₂, which promotes the activity of the edge sites and enhancement of conductivity. Our work has provided a new approach to synthesize hybridized MoS₂ for an enhanced hydrogen evolution reaction (HER).