Characterization of core@shell-structured ZnO@Sb2S3 particles for effective hydrogen production from water photo spitting

In this study, Sb2S3-photosensitized ZnO photocatalysts (ZnO@Sb2S3) are used to enhance the production of hydrogen from water by photo-splitting. Various loadings of Sb2S3 are added to the surface of rod-shaped ZnO nanoparticles (100-150 nm) as a photosensitizer to absorb visible light. The obtained particles show core@shell structures in transmission electron microscopy images. The physicochemical characteristics of the Sb2S3, ZnO, and core@shell structured ZnO@Sb2S3 particles are confirmed using X-ray diffraction, UV-visible spectroscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. H2 evolution from water photo-splitting is enhanced for the core@shell structured ZnO@Sb2S3 in a liquid system compared to that for pure ZnO and Sb2S3. Hydrogen gas is produced at a rate of 77.5 μmol/g after 10 h using the ZnO@Sb2S3 photocatalyst with a 7.0 mol% Sb2S3 loading. Based on cyclic voltammetry results, the high photoactivity of ZnO@Sb2S3 is attributed to both the fast excitation of electrons by increased absorption of visible light and the suppression of electron-hole (e--h+) recombination, which results from the appropriate energy gap between the Sb2S3 and ZnO particles.