Transition Metal Dichalcogenides Clusters Immobilized on Defective Black Phosphorus As an Efficient Electrocatalyst for Hydrogen Evolution Reaction

Abstract

Transition metal dichalcogenides (TMDs) have been intensely investigated as attractive noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER). However, it still remains a great challenge to enhance electrical conductivity, maintain high intrinsic activity and increase active site density of TMD-based electrocatalysts in practice. Herein, aided by first-principles calculations, a novel composite electrocatalyst in which the TMD clusters are immobilized on the surface of defective black phosphorus (BP) has been designed, with the promise to combine excellent intrinsic activity, high active site density, and high conductivity. The strong X–P (X = S, Se, or Te) covalent bonds between TMD clusters and defects (single and double vacancies) on the BP surface stabilize the composite structure and avoid the long-standing deactivation problem caused by cluster desorption. TMD clusters possess high active sites density, while BP acts as conducting layer to efficiently transport electrons from the electrode to active sites to ensures high conductivity. In addition, the ab-initio molecular dynamics simulations have been performed on cluster diffusion on the defective BP, illustrating the possibility of synthesizing such composite electrocatalyst by a simple drop-casting procedure at finite temperatures.