International Journal of Hydrogen Energy | 2019
3D cross-linked BiOI decorated ZnO/CdS nanorod arrays: A cost-effective hydrogen evolution photoanode with high photoelectrocatalytic activity
Abstract
Abstract ZnO/CdS photoanode with an excellent photoelectrochemical (PEC) performance for water splitting to produce hydrogen, but its practical application is seriously hindered owing to the photocorrosion induced by photoholes on the surface of CdS. Herein, a 3D cross-linked heterostructure ZnO/CdS/BiOI nanorod arrays (NRAs) has been prepared by a simple solvothermal strategy. Under visible light illumination (λ\xa0>\xa0420\xa0nm), the ZnO/CdS/BiOI NRAs photoanode shows an excellent PEC activity and generates a photocurrent density of 9.12\xa0mA\xa0cm−2 at 1.1\xa0V vs. RHE, which is 1.8 times higher than that of the ZnO/CdS NRAs photoanode in the alkaline electrolyte. Furthermore, the photoanode achieves a high photo conversion efficiency of 3.49% and a long-time stability over 6000\xa0s. It is proposed that the BiOI nanosheets not only serve as protecting layer to restrain the photocorrosion of CdS, but also facilitate the charge separation in CdS by the virtue of the p-n junction formed between CdS and BiOI.