The CO 2 photoconversion over reduced graphene oxide based on Ag/TiO 2 photocatalyst in an advanced meso-scale continuous-flow photochemical reactor

This study aims at examining the use of an advanced meso-scale continuous-flow photochemical reactor for the photocatalytic conversion of CO 2 with water into fuel over TiO 2 (P25), Ag/TiO 2 , and Ag/TiO 2 /RGO catalysts. The silver loaded photocatalysts were prepared by one-step process via hydrothermal method. The prepared photocatalysts were characterized by various characterization techniques in order to identify the morphological, chemical, physical, and optical properties. The photocatalytic activity of the as-prepared catalysts was firstly examined by the photoelectrochemical (PEC) measurements and secondly by the photocatalytic reduction of CO 2 in the proposed setup. Liquid products were analyzed using gas chromatography-mass spectrometry (GC-MS) and total organic carbon (TOC) techniques. It was found that the ternary composite revealed an outstanding performance towards CO 2 photocatalytic reduction, where its selectivity was directed towards methanol production. The incorporation of graphene nanosheets enhanced the photocatalytic reduction of CO 2 by 3.3 and 9.4 times compared with Ag/TiO 2 and bare TiO 2 , respectively, using the proposed photochemical reactor in a continuous mode. This study sheds the light on a novel type of a photocatalytic reactor where CO 2 conversion over Ag/TiO 2 /RGO ternary composite was evaluated. Graphical abstract A meso-scale continuous-flow photochemical reactor