A Comprehensive Review on Non‐Trivalent Bismuth‐Based Materials: Structure, Synthesis, and Strategies for Improving Photocatalytic Performance

Bi‐based semiconducting materials have received tremendous attention due to their availability, non/low toxicity, ecological friendship, rich chemical forms, and good visible‐light‐driven photocatalytic performance. As compared to the commonly investigated trivalent bismuth (Bi(III))‐based photocatalysts, non‐trivalent bismuth‐based materials (NTBBMs), such as BiO 2− x , Bi 2 O 4− x , Bi 4 O 7 , NaBiO 3 , and so on, exhibit excellent visible‐light‐ and even full‐spectrum‐driven photocatalytic activity as they hold narrow bandgap, suitable positions of conduction band and valence band, and relatively redox‐sensitive structures. In this review, it is attempted to summarize the recent progress in the preparation, microstructures, and modification strategies of various NTBBMs‐based photocatalysts. At the end, the advantages and disadvantages of NTBBMs‐based photocatalysts and future perspectives are presented.