TiO2 Nanosheet Arrays with Layered SnS2 and CoOx Nanoparticles for Efficient Photoelectrochemical Water Splitting

Abstract Converting solar energy into sustainable hydrogen fuel by photoelectrochemical (PEC) water splitting is a promising technology to solve increasingly serious global energy supply and environmental issues. However, the PEC performance based on TiO 2 nanomaterials is hindered by the limited sunlight-harvesting ability and its high recombination rate of photogenerated charge carriers. In this work, layered SnS 2 absorbers and CoO x nanoparticles decorated two-dimensional (2D) TiO 2 nanosheet array photoelectrode have been rationally designed and successfully synthesized, which remarkably enhanced the PEC performance for water splitting. As the result, photoconversion efficiency of TiO 2 /SnS 2 /CoO x and TiO 2 /SnS 2 hybrid photoanodes increases by 3.6 and 2.0 times under simulated sunlight illumination, compared with the bare TiO 2 nanosheet arrays photoanode. Furthermore, the TiO 2 /SnS 2 /CoO x photoanode also presented higher PEC stability owing to CoO x catalyst served as efficient water oxidation catalyst as well as an effective protectant for preventing absorber photocorrosion.