Facile synthesis of ZnO nanorods grown on graphene sheets and its enhanced photocatalytic efficiency

BACKGROUND Recent advancements in nanoscale materials have focused on well‐designed nanocomposites that are highly oriented and organized. Three‐dimensional arrays consisting of one‐dimensional ZnO nanorods grown on reduced graphene oxide (RGO) sheets should be an efficient photocatalyst for photocatalytic hydrogen production from glycerol solution due to the increased adsorptivity of the reactant, extended light absorption range, and especially efficient charge transportation and separation. RESULTS It was found that the calcination temperature of the ZnO seed layer had a significant influence on the morphology, surface structure, optical and electronic properties of ZnO/RGO nanocomposites. When the calcination temperature of the ZnO seed layer was 400 °C, ZnO nanorods grown on graphene sheets with C–O–Zn linkages can be achieved. This sample exhibited the highest photocatalytic H2 production rate. CONCLUSION The results of this study show that superior photocatalytic performance originates from the higher transfer rate of photo‐generated electrons from ZnO to RGO, and repressed recombination of the photoinduced hole–electron pairs of ZnO, which is closely related with the chemical interaction between ZnO and RGO and the concentration of Zn–O–C bonds. Moreover, the morphology of ZnO nanorods favors the directional transfer of electrons in ZnO. © 2014 Society of Chemical Industry