Action and mechanism of semiconductor photocatalysis on degradation of organic pollutants in water treatment: A review

Abstract

Semiconductors photocatalyst, applied in the degradation of organic pollutants in water, were summarized due to its durability, low cost, low toxicity, super-hydrophilicity, and remarkable chemical and photochemical stability. Firstly, this paper intensively summarized the photocatalytic activity of single semiconductors photocatalyst. However, single semiconductors photocatalyst showed some drawbacks that is fast recombination of electron/hole, low adsorption about visible light and low surface coverage of photocatalysts. Thus, coupling semiconductors with desirable matching electronic bandgap and doping semiconductor photocatalysts have been discussed detailly. Notably, the Ag-based semiconductor photocatalysts has been highlight. The indicators for evaluating photocatalysis properties including pollution adsorption, kinetic and recyclability were discussed in detail. In addition, the mechanisms of photocatalytic reaction were discussed, which showed the mechanism is redox reaction and the process could degrade a wide range of organic pollutants into easily degradable intermediates or less toxic small molecular substances.