Near infrared-driven hydrogen evolution via copper bismuth selenide/reduced graphene oxide hybrid for enhanced photo(electro)catalysis

Abstract

Photoelectrochemical (PEC) water splitting represents a promising solution for sustainable hydrogen production, yet its practical application is constrained by the need for efficient, cost-effective, and durable photoelectrodes. This study introduces copper bismuth selenide (CBS), a binary metal chalcogenide and a p-type semiconductor, as a low-cost and facilely synthesized photoelectrode for PEC water splitting. Marking its first application in this domain, CBS demonstrates strong near-infrared (NIR) absorption, extending its spectral response beyond the visible range to enhance solar energy harvesting and conversion. To address the high recombination rates associated with its narrow bandgap, an in situ-formed reduced graphene oxide (rGO) is integrated into the material, forming a 2D-2D interface. This CBS/rGO composite significantly improves charge separation and carrier transport, mitigating recombination losses and enhancing overall photoelectrode performance. The composite achieved an impressive photocurrent density of −2.68 mA cm⁻² at −0 V_RHE. Additionally, CBS exhibited strong potential as a bifunctional electrocatalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in electrocatalytic water splitting. These findings establish CBS as a promising candidate for advancing PEC technology, offering a scalable and sustainable approach to clean hydrogen generation.