Indium Oxides and Related Indium‐based Photocatalysts for Water Treatment: Materials Studied, Photocatalytic Performance, and Special Highlights

In 2 O 3 is an emerging material in the photocatalysis research area, with a surge in the number of studies examining indium‐based materials as photocatalysts in recent years. The materials of interest, herein, span the simple indium oxide in different polymorphs and morphologies, ternary, and even quaternary indium oxides, heterostructured systems, all in pure or doped forms. These indium‐based materials offer advantages as photocatalysts compared with the conventional titanium dioxide‐based photocatalysts. Highlights in the literature include reports of the ability of indium oxide to degrade difficult to decompose aqueous organic contaminants while also offering opportunities for visible light activation. These are exciting achievements in this field of research. The unique properties that these materials offer are uncovered, while giving insights as to how indium oxides and related indium‐based materials can be used, in what capacity and the compositional requirements when matched with other semiconductors to achieve high‐performing photocatalysts.