Development and Evaluation of Ag-TiO2 Nano-photocatalysts for the removal of natural organic matter and pharmaceuticals

Abstract

Increasing the population and growing industries lead to contamination of surface and groundwater and threaten the sustainability of aquatic ecosystems and water resources. Some of the main contributors to water pollution include domestic wastes, industrial discharges, and excess use of pharmaceuticals and personal care products as well as pesticides and fertilizers. The incapability of conventional techniques to remove the contaminants has created a need for innovative water treatment solutions, such as advanced oxidation processes (AOPs). AOPs are aqueous phase oxidation methods based on the creation of highly reactive chemical species that mineralize organic pollutants. TiO2 has been widely studied as photocatalysis in AOPs to remove contaminants in water treatment applications. However, the low efficiency under solar irradiation and difficulty in recovering photocatalysis have limited its applications in commercial scale. Doping metals and non-metals to TiO2 structure is a possible mechanism to increase the efficiency and overcome the limitation of using TiO2 in water treatment industries. In the current study, graphene (G) as non-metal and silver (Ag) as a metal dopant were selected to compare the efficiency of photocatalytic reactions of P25 which is the commercial name of TiO2.