G-C3N4/TIO2 NANOCOMPOSITES AND THEIR APPLICATION IN PHOTOCATALYTIC CO2 REDUCTION: A MINIREVIEW

g-C3N4/TiO2 nanocomposites seem to be promising materials for photocatalytic reductive applications such as water splitting and CO2 reduction. The g-C3N4 is known as a metal-free semiconductor exhibiting a high reductive conduction band (CB) (-1.3 V vs. NHE) and visible light absorption (Eg =2.7 eV), while TiO2 is the most popular photocatalyst. However, both semiconductors show high electron/hole recombination, and in the case of TiO2, lack of visible light absorption. Both problems could be overcome by designing type II heterojunctions or a direct Z-scheme between g-C3N4 and TiO2. These strategies make these composites suitable for CO2 photocatalytic reduction and solar fuel production. Herein, the main aspects related to photocatalytic CO2 reduction in aqueous media to obtain solar fuels such as methane and methanol, synthesis of g-C3N4/TiO2 nanocomposites, and their reactivity will be addressed and reviewed.