Vertically Aligned MoS₂ with In-Plane Selectively Cleaved Mo-S Bond for Hydrogen Production.

Abstract

Perturbing the periodic electronic structure of the MoS₂ basal plane via vacancy engineering offers an opportunity to explore its intrinsic activity. A significant challenge is the design of vacancy states, which include its type, distribution, and accessibility. Here, well-dispersed and vertically aligned MoS₂ nanosheets with an in-plane selectively cleaved Mo-S bond on a carbon matrix (c-MoS₂-C) have been prepared by a self-engaged strategy, which synergistically realizes uniform vacancy manufacturing and three-dimensional (3D) self-assembly of the defective MoS₂ nanosheets. X-ray adsorption spectroscopy investigation confirms that the cleaved MoS₂ basal plane generates newly active edge sites, where the Mo centers feature unsaturated coordination geometry. Theoretical calculations reveal that the exposed interior edge Mo sites represent new active centers for hydrogen adsorption/desorption. As expected, the synthesized c-MoS₂-C exhibits markedly enhanced hydrogen evolution activity and superior stability. This in-plane activation strategy could be extended to other types of transition-metal dichalcogenides and catalytic reaction systems.