Structure phase engineering strategy through acetic acid coupling to boost hydrogen evolution reaction performance of 2H phase MoS2 at wide pH range

Abstract

The semiconductor phase molybdenum disulfide (2H-MoS2) with poor hydrogen evolution reaction (HER) performance restricts the further improvement of hydrogen production. Herein, an acetic acid coupled structure phase engineering (SPE) strategy is developed to synthesize a homogeneous and orderly cobalt molybdenum composite structure. The resulting CoS2/MoS2 complexes reveal excellent HER activity with a low overpotential of 80, 95, and 135 mV at 10 mA cm−2 in 0.5 M H2SO4, 1 M KOH, and 1 M PBS. Fourier transform infrared spectroscopy (FT-IR) and thermogravimetry mass spectrometry (TGA-MS) results illustrate that acetic acid is successfully coupled at the interface between CoS2 and MoS2. Results from density functional theory demonstrate that the π-π conjunction formed by acetic acid coupling can work as a bridge to help electrons transfer from cobalt to molybdenum. More importantly, the method can be extended to the synthesis of other composite materials with the similar structure.