g-C3N4/TiO2 NANOCOMPOSITES AND THEIR APPLICATION IN PHOTOCATALYTIC CO2 REDUCTION: A MINIREVIEW

Abstract

g-C3N4/TiO2 nanocomposites seem to be promising materials for photocatalytic reductive applications such as water splitting and CO2 reduc-tion. The g-C3N4 is known as a metal-free semicon-ductor 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 photocata-lyst. However, both semiconductors show high elec-tron/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 di-rect Z-scheme between g-C3N4 and TiO2. These strat-egies make these composites suitable for CO2 photo-catalytic reduction and solar fuel production. Herein, the main aspects related to photocatalytic CO2 reduc-tion in aqueous media to obtain solar fuels such as me-thane and methanol, synthesis of g-C3N4/TiO2 nano-composites, and their reactivity will be addressed and reviewed.