Zinc oxide: reduced graphene oxide nanocomposite film for heterogeneous photocatalysis

The nanocomposite film based on zinc oxide nanostructures and reduced graphene oxide bilayer (ZnO/rGO) was synthesized, characterized and tested for the photodegradation of model organic dye (methyl orange) in water. Specifically, the nanorods of zinc oxide were obtained by the hydrothermal methods on the surface of rGO bilayers deposited on the quartz surface. The kinetics of dye photodegradation was studied via measurement of variation of the optical density at the maximum observed for the dye at 465 nm. The photodegradation efficiency of methyl orange (MO) was found to be increased from 70 to 85% when the nanocomposite material was used instead of pure ZnO nanostructures. The reaction rate constants calculated using the first-order approximation were equal to 7.2 × 10−3 min−1, 1 × 10−3 min−1 and 1.4 × 10−2 min−1 for ZnO nanorods, rGO bilayer, and ZnO/rGO nanocomposite, respectively. Hence, the rate constants clearly indicate that ZnO and rGO are functioning in a synergistic manner in the fabricated nanocomposite photocatalyst. It is necessary to point that the sample keeps its integrity after multiple experiments that is important for practical applications. The obtained results evidently demonstrate potential of the nanocomposite films based on ZnO nanostructures and rGO bilayers for production of the efficient catalysts.