Defective molybdenum sulfide quantum dots as highly active hydrogen evolution electrocatalysts

摘要

Molybdenum disulfide (MoS2),a promising non-precious electrocatalyst for the hydrogen evolution reaction with two-dimensional layered structure,has received increasing attention in recent years.Its electrocatalytic performance has been limited by the low active site content and poor conductivity.Herein,we report a facile and general ultrafast laser ablation method to synthesize MoS2 quantum dots (MS-QDs) for electrocatalytic HER with fully exposed active sites and highly enhanced conductivity.The MS-QDs were prepared by ultrafast laser ablation of the corresponding bulk material in aqueous solution,during which they were partially oxidized and formed defective structures.The as-prepared MS-QDs demonstrated high activity and stability in the electrocatalytic HER,owing to their very large surface area,defective structure,abundance of active sites,and high conductivity.The present MS-QDs can also find application in optics,sensing,energy storage,and conversion technologies.