“…Therefore, researchers have focused on unearthing visible-light-active photocatalysts that can efficiently utilize solar light. [23] Various types of metal oxides, such as CuWO 4 , [24] BiVO 4 , [25] WO 3 , [26] Bi 2 MoO 6 , [27] CuO, [28] CuFe 2 O 4 , [29] Fe 2 O 3 , [30] and Bi 2 O 3 , [31] have been widely studied as promising visible-light-active photocatalysts. WO 3 is considered one of the most promising photocatalysts because of its appropriate bandgap and adequate valence band position, enabling it to efficiently mediate oxidative radicals.…”