Hierarchical Waterweed-like Photoanodes for Sustainable Photoelectrochemical Hydrogen Production

Nanostructured photoanodes (PAs) applied to photoelectrochemical water splitting have demonstrated outstanding performance, but the limitations in light harvesting require further advances in the design of PAs. Herein, waterweed-like PAs were proposed as a highly efficient PA for photoelectrochemical water splitting. The waterweed-like PAs were prepared by directly depositing Cu dendrites on flexible meshes through a template-free electrochemical deposition process and then coated with a nano-g-C3N4 catalyst through an electrophoresis process, which was ultimately used as the PA. The superiority of our design concept was verified by obtaining an unprecedented photocurrent density in photocatalytic hydrogen evolution over 96 μA/cm–2 and was 96 times higher than that of the flat-type PA with the same projected area. The excellent photocatalysis performance of the waterweed-like PA originated from the efficient capture of sunlight and large surface area for catalyst loading. In conclusion, the waterweed-like PA is a promising PA material that can be linked together to form a large-scale floating network for hydrogen production across different water surfaces.