Applications of Transition Metal Oxides and Chalcogenides and their Composites in Water Treatment: a review

Abstract

High population growth, industrialization, precipitous urban settlement, and poor government policies in some circles have increased resource consumption and various environmental activities that promote water pollution. Diverse materials such as nanomaterials, quantum dots, carbonaceous materials, and quaternary-metallic oxides have been very successful in removing benign pollutants from contaminated water bodies. Lately, transition metal oxides (TMOs) and transition metal chalcogenides (TMCs), and their composites have attracted favorable research interest in environmental applications due to their flexible elemental composition, manipulatable bandgaps, earth abundance, optoelectrical properties, visible light activity, and catalytic stability. This review explores the applications of these binary, ternary, quaternary, and heterostructure TMOs and TMCs for a broad range of biological, organic, and inorganic pollutants in water and wastewater treatment. The most popular water treatment strategies used include photocatalysis, adsorption, antimicrobial, persulfate/peroxymonosulfate activation, and the Fenton-like process. The mechanisms of catalysis for these processes were briefly highlighted. Lastly, the conclusion and prospects of the use of the TMOs and TMCs in water and wastewater treatment were discussed.