CoNi2S4 cocatalyst modified TiO2 nanorods/nanoflower homojunction for efficient photoelectrochemical water splitting

Photoelectrochemical water splitting is a promising green method for obtaining clean energy, and its core lies in the preparation of high-performance photoanodes. In this study, TiO2 nanorods/nanoflower homojunction photoanodes were prepared using a one-step hydrothermal method, unlike the complex material composite process used in most previous research works, the TiO2 homojunction photoanode obtained through a one-step method combines the advantages of nanorod and nanoflower structures. CoNi2S4 was further used as an oxygen evolution cocatalyst supported on the TiO2 nanorods/nanoflower homojunction photoanodes, enhancing oxygen evolution kinetics. The photogenerated current density of the obtained TiO2 flower-rod/CoNi2S4 composite photoanode at 1.23 V (versus RHE) was 1.64 mA cm−2, which is 2.3 times of that of TiO2 nanorod photoanode. By density function theory calculation, it is confirmed that the loading of CoNi2S4 cocatalyst can significantly reduce the overpotential and enhance the kinetic process of oxygen evolution reaction.