Surface Sulfur Vacancy Engineering of Metal Sulfides Promoted Desorption of Hydrogen Atoms for Enhanced Electrocatalytic Hydrogen Evolution
Tariq Ali, Wei Qiao, Dongsheng Zhang, Weifeng Liu, Saman Sajjad, Chenglin Yan, Ren Su
Abstract
Sulfur vacancy (SV) engineering is an evolving approach to improve the performance of metal sulfides for hydrogen evolution reactions (HER); however, a simple and universal method for creating SV is still missing; thus, the catalytic role of SV in elemental steps of HER remains unclear. Here, we develop a facial hydrothermal process employing hydrochloride acid as the sulfur etching agent to synthesize high-performance MoS2-based electrocatalysts. Surface vacancy-engineered MoS2 shows a 32-fold enhancement in HER compared to pristine MoS2, owing to the promoted desorption of hydrogen atoms. This strategy is also applicable for the development of other metal sulfides. Vacancy-engineered CoMoS2 displays a η10mA of −0.23 V vs the reversible hydrogen electrode (RHE) and outperforms the Pt electrode at high current density owing to the optimized desorption of hydrogen.