Nanostructured CuO with a thin g-C 3 N 4 layer as a highly efficient photocathode for solar water splitting.

A g-C 3 N 4 /CuO nanostructure featuring improved photoelectrochemical properties was successfully prepared using a facile and cost-effective method involving electrodeposition and thermal oxidation. The improved photoelectrochemical properties were mainly ascribed to the increased surface area and improved charge transportation of the g-C 3 N 4 /CuO photocathode. This photocathode can be used in novel strategies for resolving problems associated with low-efficiency CuO photocathodes.