Self-Supported Bi₂MoO₆ Nanowall for Photoelectrochemical Water Splitting

The nanowall has been regarded as a promising architecture for highly efficient photoelectrochemical (PEC) water splitting due to various advantages, such as open geometry, highly reactive facets, independent contact with current collector, and so forth. Here, a vertically aligned Bi₂MoO₆ nanosheet array, which is also called a nanowall, is first achieved directly on the ITO glass by a facile solvothermal approach. The structural features not only offer multiple superiorities for PEC processes, but also provide the bridge for in-depth insights of intrinsic features of Bi₂MoO₆ photoanodes. A quantitative analysis of the electrochemical process declares that the utilization of photogenerated charges in the Bi₂MoO₆ nanowall has been optimized, but the main obstacle comes from the severe bulk recombination and low efficiencies of charge separation. This evaluation both enriches the visual assessment methods and directs clear guidance for future improvement, which could serve as a beacon for well-directed and economic photoelectrode amelioration, to shorten the road toward ideal photoelectrodes.