ABSTRACT
Various semiconductors and their composites are extensively studied for the photocatalytic reduction of CO2. Nanostructured composite of graphene oxide with various semiconductor materials exhibits higher photocatalytic performance because of transfer of electrons from semiconductors to graphene oxide which can move apart on the surface. The nanostructured composite of N-doped graphene with various semiconductor materials has been proven to show superior photocatalytic performance. Various nanostructured composites including semiconductors and carbon materials hybrids have been explored thoroughly for photocatalytic activation of water, carbon dioxide and other molecules. Semiconductor materials work as photocatalyst due to the presence of band gap. The band gap of semiconductors is determined by the energy difference between hybridized system of highest occupied molecular orbital and lowest unoccupied molecular orbital (LUMO) of the material. For the efficient transfer of electrons from metal complex molecule to semiconductor, the position of LUMO of the metal complex should be higher in energy than the conduction band edge of the semiconductor.
