Interface engineering optimizes the built-in electric field and carrier migration pathways of CdS/Sb2S3 for an efficient pyro–photo-electric catalytic system

Abstract

Rational interface engineering in heterojunctions is essential for optimizing the photoelectrode performance in PEC water splitting. Therefore, we propose an idea to construct face-to-face CdS/Sb₂S₃ heterojunctions with a large specific surface area and few defects to optimize the generation and migration of pyro/photo-generated carriers in the pyro–photo-electric catalytic system. The experimental findings indicate that the interface-engineered face-to-face structure has a photocurrent density of 4.51 mA cm⁻² for the reversible hydrogen electrode (RHE) at 1.23 V, which is 43% higher than that of the point-to-face structure before interface engineering. And the incident photon-to-current efficiency (IPCE) increases to 33.42% at 400 nm. Combining the excellent behavior, it can be found that interface engineering provides stronger interfacial interactions to create consecutive carrier migration pathways and a larger pyroelectric field to improve the pyro/photo-generated carrier transfer efficiency. This paper provides a novel idea for improving the heterojunction performance and optimizing the application of heat energy and light energy from the sun in water splitting.