Activity Enhancement in Photocatalytic Reduction of CO₂ over Nano-ZnO Anchored on Graphene

The hydrothermal synthesis procedure was used to prepare the photocatalysts of ZnO nanoparticles (NPs) anchored on graphene (Gr). The activity enhancement of pristine ZnO NPs by anchored on graphene was evaluated for photocatalytically reducing CO₂. The experimental results showed that the graphene could significantly improve the photocatalytic activity, where ZnO NPs anchored on 30 wt% Gr showed the best photocatalytic performance for achieving the highest yield of methanol up to 2772.9 μmol/h·g_cat. The enhanced photocatalytic could be attributed to the following reasons. The first one was that the light was harvested on the 2D graphene dispersed ZnO NPs uniformly. And the second one was the combination of ZnO NPs and graphene in ZnO NPs/Gr photocatalysts could transfer charge to separate photogenerated electron and hole efficiently, which was confirmed by the photoluminescence analysis.