Exploring Semiconducting Nature of Atomic‐Level Thin Bismuthene Nanosheets for Photoredox Reactions

Bismuthene, 2D nanosheets of bismuth with a graphene‐like structure, shows semiconducting property in contrast to its semimetallic bulk form. This led us to synthesize atomic‐level thin (2 nm) bismuthene nanosheets and explore its application for photoredox reactions. In the presence of light, bismuthene catalyzes the formation of aryl radical, which is efficiently utilized for the C sp ² –C sp ² , C sp ² –P, C sp ² –O, C sp ² –B, etc., cross‐coupling reactions. Further, the catalyst can be recycled five times with a minimum loss of activity. The transient absorption spectroscopy reveals the underlying mechanistic aspects that govern the catalytic efficiency of bismuthene.