“…Considering that visible light energy accounts for about 45% of sunlight energy [ 37 ], subsequently, in order to broaden the light-harvesting range, remarkable efforts have been devoted to explore visible light-activated semiconductors including CdSe, CdS, SiC, WO 3 , Fe 2 O 3 , Co 3 O 4 , g–C 3 N 4 , CdO, Ag 2 O et al as photocatalysts, which possess a narrow band gap that is less than or equal to 3.0 eV. Recently, bismuth-based (Bi-based) semiconductors with advantages of non-toxicity, low cost and good thermal stability and as new and important visible light-activated semiconductors have become a research hotspot [ 20 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. Bi-based semiconductors usually refer to the Bi 3+ containing semiconductors because of the higher stability of Bi 3+ than Bi 5+ .…”