Inorganic Metal Oxides and Multi-Component Nanocomposites Based Photocatalysts for the Superior Degradation of Pollutants from Water

Abstract

Water is a primary and essential source of every living organism and it is a most precious gift of Mother Nature which helps every living creature to survive. However, this water is highly polluted now-a-days by various unethical activities by human beings. Many industrial units like textile mills, pharmaceutical units, mines, paper mills, dyeing units, sugar industries, leather purifying units, electroplating plants, fine chemical units, oil refineries, etc. produce huge amount waste products in the form of toxic chemicals and pollutants every day and enter the water bodies without proper treatment. Various techniques are available to purify the polluted water by eliminating the toxicity of pollutants; some of them are reverse osmosis, electrode ionization, ion exchange, submicron filtrations, etc. Among all these water treatment procedures, photocatalysis is found to be most versatile, low cost and environmentally benign technique. In this review, a prime focus is given on the performance of different photocatalysts based on ZnO, CuO, NiO, SnO2, MgO, multicomponent metal oxides and composites in degrading and removing unwanted impurities present in polluted water. The importance of using metal oxide based photocatalyts in treating the polluted water is also discussed.