The coupling effect of carbon spheres and cobalt-involved carbon nitrides stacked on TiO2 nanorod arrays for promoted solar water oxidation

Photoanode materials typically exhibit good stability and environmentally and economi-cally properties in solar water splitting cells, while they always suffer from the narrow light absorption range, heavy surface charge combination and sluggish surface reaction ki-netics. Herein, we design an efficient and reproducible photoanode by stacking amorphous carbon spheres (CSs) and cobalt-involved carbon nitrides (Co-CNs) on surface of TiO2 nanorod arrays. CSs work as light sensitizer for broadening the light absorption range of photoanode and promoting the utilization of solar energy, which further improved by Co-CNs partially. In addition, CSs increase the conductivity of photoanode, as a transport channel for improving the charge migration. Co-CNs introduce many active sites on sur-face of photoanode for facilitated solar water oxidation. The best constructed TiO2/CSs/Co-CNs photoanode exhibits an impressive photocurrent density of-1.73 mA/cm2 (at 1.23 V vs RHE). The staking method of various functional materials provides one promising strategy for the modification of catalysts.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.