Metal oxides for Fenton reactions toward radical-assisted water treatment: A review

Water purification is a crucial task in the advancement of human civilization as it plays a significant role in environmental preservation. So far, complex processes and various methods have been utilized to treat contaminated water. Water treatment using radicals via oxidation–reduction is a chemically advanced oxidation process. This reaction is carried out using a metal oxide and a radical precursor. Metals react with oxygen molecules to produce oxides, peroxides, or superoxides. The oxide forms of transition metals have been studied as catalysts and as alternatives to precious metals due to their high stability and low price. This review summarizes recent research activities focused on water treatment using transition metal oxides, bimetallic oxides, and metal oxides doped with co-catalysts.