Monolayer MoS2 quantum dots as catalysts for efficient hydrogen evolution

Abstract

Monolayer MoS₂ quantum dots (QDs) with lateral size around 3 nm were prepared through an effective multi-exfoliation based on lithium (Li) intercalation. The effects of the number of exfoliation on the microstructures and electrocatalytic activities of hydrogen evolution reaction (HER) for MoS₂ nanosheets were examined. The lateral size of the nanosheets decreases rapidly with increasing the number of exfoliation. The obtained monolayer MoS₂ QDs exhibit improved HER catalytic activities with a low overpotential of approximately 120 mV and a relatively small Tafel slope of 69 mV dec⁻¹. Both the ultrathin structure and the abundance of exposed active edge sites make monolayer MoS₂ QDs a promising HER electrocatalyst for practical application.