Improved interfacial bonding of graphene-TiO2 with enhanced photocatalytic reduction of CO2 into solar fuel

Abstract This study focuses on the improvement in the interfacial bonding of reduced graphene oxide (rGO) and titanium dioxide (TiO 2 ) and important factors which contributed towards the enhanced photocatalytic activity of rGO/TiO 2 photocatalyst. A facile two-steps approach was employed to synthesize the rGO/TiO 2 which involved partial reduction of graphene oxide followed by vacuum thermal treatment. The properties of rGO/TiO 2 photocatalysts were thoroughly investigated using SEM, XRD, FTIR, XPS, Raman, PL, N 2 adsorption/desorption, and UV–vis spectroscopy. The performance of photocatalysts was evaluated for the reduction of CO 2 with H 2 O using a continuous gas phase fixed bed photoreactor. The highest amounts of methane (CH 4 ) and carbon monoxide (CO) were 12.75 and 11.93 μmol g −1  h −1 over 0.4 wt.% rGO/TiO 2 that were 4 fold greater compared to anatase TiO 2 . Improved photocatalytic activity was attributed to interfacial chemical bonding (Ti O C), efficient transfer of electrons, enhanced light absorption and higher adsorption of CO 2 due to rGO. Thus, this development could provide an efficient approach to improve the interfacial bonding in graphene based nanocomposites for photocatalytic applications.