Photocatalytic hydrogen evolution mechanisms mediated by stereoactive lone pairs of Sb2VO5 in quantum dot heterostructures

Photocatalytic water splitting is a promising approach to generate clean hydrogen fuel and reduce climate change. Emulating Nature, semiconductor heterostructures with optimally aligned electronic states represent a promising design strategy. We report a tunable photocatalytic architecture by interfacing chalcogenide quantum dots (QDs) with Sb2VO5, a metal oxide semiconductor with a high density of optimally positioned lone -pair -derived mid -gap states, which enables barrier -less hole extraction from photoexcited CdS QDs. Comprehensive photoelectrochemical analyses show that the photoinduced charge carriers can catalyze reduction or oxidation half -reactions depending on the electrolyte composition, reactor environment, and the presence of co -catalysts. Ligandbridged Sb2VO5-cysteine-CdS heterostructures photocatalytically generate H2 without the need for an applied potential, external circuit, or counter electrode. The results provide a remarkable demonstration of the design of photocatalytic heterostructures based on electronic structure considerations to reduce energetic offsets and improve interfacial charge transfer to efficiently generate carbonfree H2.