Fundamentals principle of photocatalysis

Photocatalysts are widely used for the removal of hazardous pigments, contaminants, microorganisms, and toxic pollutants from the environment. Generally, nanoscale semiconductors are utilized as a catalyst but they are less efficient due to its wider bandgap. Its efficiency can be increased by doping with suitable materials which will reduce the bandgap of the material and also makes the catalyst active in the visible region. This chapter mainly discusses the reaction pathways followed by the photogenerated electron hole pairs, and fundamental principle and factors affecting the catalytic activity of the nanosized particles. This chapter also encourages the reader to follow the various strategies for enhancing photocatalytic properties of semiconducting materials by making heterojunctions with semiconductor, metal, carbon, or multicomponent oxides.