Vertical graphene on rice-husk-derived SiC/C composite for highly selective photocatalytic CO2 reduction into CO

Coupling graphene-based materials with SiC nanostructures is one of the most feasible strategies to improve the photocatalytic CO 2 reduction performance. Here, we synthesized the vertical graphene (VG) sheets on the SiC nanowires achieved from rice husks to form the VG@SiC/C composite, in which the VG sheets possess high surface area, excellent electrical conductivity , and chemical stability, and the SiC nanowires have a suitable bandgap for sunlight absorption. The resulting VG@SiC/C composite provides an enhanced photocatalytic reduction of CO 2 to CO and CH 4 , yielding CO and CH 4 evolution yields of 25.5 and 2.3 μmol g −1  h −1 , respectively. The achieved CO yield is maximal so far among the SiC-based photocatalysts . The defective VG sheets promote the absorption of sunlight, enhance the CO 2 adsorption and activation, increase the separation of photogenerated electron-hole pairs, improve the activity of photocatalyst, and thereby prompt the photocatalytic reduction of CO 2 to CO with high yield and selectivity.