VSe2 quantum dots with high-density active edges for flexible efficient hydrogen evolution reaction

Abstract

Two dimensional (2D) metallic transition metal dichalcogenides (TMDCs) with large specific surface area and high conductivity is a promising catalyst for the electrocatalytic hydrogen production. The highly active edges of the 2D metallic TMDCs are the desirable catalytic sites for hydrogen evolution reaction (HER). Herein, the VSe2 quantum dots with high-density edge sites are prepared by tip sonication of the self-detached VSe2 nanosheets. The spontaneously released VSe2 nanosheets, without chemical-involved transfer, offer a non-contaminated catalyst for HER. Comparing to the VSe2 nanosheets, the VSe2 quantum dots with a high density of active edges present a significant enhancement of the electrocatalytic performance. The reduced overpotential and transfer resistance indicate the lower Gibbs free energy and faster faradic process of the VSe2 quantum dots for HER. The active edge sites of VSe2 quantum dots show improved catalytic properties in thermodynamic and kinetic aspects. The VSe2 quantum dots loaded on a carbon cloth could be used as a flexible electrode for HER. This work provides an effective way to regulate the defects of the 2D TMDCs for high-performance HER catalyze, and also offers a catalyst for flexible HER.