Title : Recent developments in metal oxide-Based photocatalysts for environmental remediation and clean energy production: An overview
Abstract:
With the rapid urbanization as well as industrialization, the demand is increasing for pollution-free sustainable environment and clean energy production. Therefore, there are urgent needs for developing appropriate technologies for decontaminating the environment against pollutants and generating new renewable energy sources as alternative to depleting fossil fuel. The toxic organic and inorganic chemicals present in the environment exhibit detrimental effects to living bodies as well the the eco system. Employing nanosize metal oxides as photocatalysts is emerging a promising approach for degrading environmental pollutants to non-toxic products such as CO2, H2O, and minerals. Metal oxides, owing to their sufficient availability, non-toxicity, ease of fabrication, stability, and high surface area make them useful in a wide range of applications. Generally used TiO2, ZnO, WO3, Cu2O and CeO2, have been recognized as cost-effective and efficient photocatalysts for environmental remediation. More recently, these are also being explored for CO2 conversion to clean energy sources such as hydrogen gas and alcohols. This study discusses characteristics of some metal oxides and their applications as photocatalysts for the environmental remediation and generation of renewable energy products. The modifications made on metal oxides to overcome their limitations such as wide band-gap, high recombination rate of photo-generated electron-hole pairs, and catalyst deactivation, have been highlighted. The size-controlled synthesis of metal oxides and their composite nanostructures, with varying morphologies, photocatalytic reaction pathways, issues relating durability as well as reusability as photocatalysts, and the strategies adopted to improve CO2 conversion efficiency to renewable fuels, are discussed in detail.
