Photocatalytic reduction of graphene oxides hybridized by ZnO nanoparticles in ethanol

Graphene oxide platelets synthesized by using a chemical exfoliation method were dispersed in a suspension of ZnO nanoparticles to fabricate ZnO/graphene oxide composite Formation of graphene oxide platelets (with average thickness of similar to 0 8 nm) hybridized by ZnO nanoparticles (with average diameter of similar to 20 nm) was investigated The 2D band in Raman spectrum confirmed formation of single layer graphene oxides The gradual photocatalytic reduction of the graphene oxide sheets in the ZnO/graphene oxide suspension of ethanol was studied by using X-ray photoelectron spectroscopy for different ultra violet (UV)-visible irradiation times After 2 h irradiation, the relative concentration of the C-OH, C=O and O=C-OH bonds showed nearly 80% reduction relative to the corresponding concentrations before irradiation The chemical reduction was accompanied by variations in the optical absorption of the ZnO/graphene (oxide) suspension, as its color changed from light brown to black The current-voltage measurement showed that electrical sheets resistance of the ZnO/graphene oxide sheets decreased by increasing the irradiation time Therefore, the ZnO nanoparticles in the ZnO/graphene oxide composite could be applied in gradual chemical reduction and consequently tuning the electrical conductivity of the graphene oxide platelets by variation of UV irradiation time in a photocatalytic process (C) 2010 Elsevier Ltd All rights reserved