fig3

Figure 3. Typical crystal structure and energy-band structures of key bismuth-based catalysts. (A) Perovskite-like layered structure of BiOX (X = Cl, Br, I), (B) Bi₂MO₆ (M = W, Mo), (C) ABO₃, (D) Bi₂X₂O₇ (X = Sn, Ti, Zr).