Recent Advances in Bismuth‐Based Nanomaterials for Photoelectrochemical Water Splitting

Abstract In recent years, bismuth‐based nanomaterials have drawn considerable interest as potential candidates for photoelectrochemical (PEC) water splitting owing to their narrow band gaps, nontoxicity, and low costs. The unique electronic structure of bismuth‐based materials with a well‐dispersed valence band comprising Bi 6s and O 2p orbitals offers a suitable band gap to harvest visible light. This Review presents significant advancements in exploiting bismuth‐based nanomaterials for solar water splitting. An overview of the different strategies employed and the new ideas adopted to improve the PEC performance of bismuth‐based nanomaterials are discussed. Morphology control, the construction of heterojunctions, doping, and co‐catalyst loading are several approaches that are implemented to improve the efficiency of solar water splitting. Key issues are identified and guidelines are suggested to rationalize the design of efficient bismuth‐based materials for sunlight‐driven water splitting.