Highly enhanced performance of heterojunction Bi2S3/BiVO4 photoanode for photoelectrocatalytic hydrogen production under solar light irradiation

Abstract

A heterojunction structure of BiVO4 coupled with a narrow bandgap photocatalyst Bi2S3 was fabricated forming a composite material with strong capacity in visible light absorption and enhancement in the separation rate of photogenerated charge carriers owing to their suitable band structures. As a result, efficiency of hydrogen production through photoelectrocatalysis is highly enhanced. The morphology and composition of as-prepared sample electrodes are measured through X-Ray Diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The performance of the hybrid nanostructure Bi2S3/BiVO4 photoelectrode was found to be related to the growing process of Bi2S3 nanowire during the hydrothermal preparation process. The composited Bi2S3/BiVO4 photoanode achieved a photoconversion efficiency of 2.9% which is nearly 3-fold that of the bare BiVO4 electrode under visible light irradiation, while the hydrogen production was greatly enhanced by nearly 5-fold in the photoelectrocatalytic hydrogen production reaction.