Preparation And Photocatalytic Properties Of Different Morphologies Of Cupprous Oxide-graphene Nanocomposite Systems

With the environmental pollution and energy shortage becoming more and more serious,extending the range of photocatalytic reaction to the effective use of clean solar energy to solve environmental problems has gradually become a research hotspot.As a narrow bandgap p-type semiconductor,cuprous oxide（Cu₂O）has been widely used in photocatalysis.To improve the photocatalytic activity of Cu₂O,in this paper,we used graphene oxide as the carrier to prepare cuprous oxide-reduced graphene oxide（Cu₂O-RGO）nanocomposite systems with different morphologies and further investigate their photocatalytic properties under visible light.The main contents are as follows:（1）The cubic and octahedral Cu₂O particles were controllably prepared by the wet chemical reduction method.The prepared particles were regular and uniform in size.The average diameters of the two particles were 800and 700 nm,respectively.The cubic and octahedral Cu₂O-RGO nanocomposite systems were prepared by in-situ reduction method with graphene oxide as the carrier.The particle sizes of Cu₂O particles were obviously smaller with average diameters of 300 nm and 250 nm,respectively.The optimum preparation conditions were determined by studying the effect of reaction conditions,such as the dosage of reactants,reaction temperature and reaction time on the prepared nanocomposites.（2）The photocatalytic properties of cubic and octahedral Cu₂O-RGO nanocomposite systems were studied.The degradation of methyl orange under visible light irradiation was conducted.The octahedral Cu₂O-RGO nanocomposite systems turned out to have the best photocatalytic activity with the apparent rate constant at 82.88×10^-3 min^-1.Meanwhile a series of experiments were carried out to study the photocatalytic mechanisms of the nanocomposite systems.The mechanism of the synergetic effect of Cu₂O and graphene was put forward.The innovations of this paper lie on:The optimal preparation methods of cubic and octahedral Cu₂O-RGO nanocomposite systems were obtained by optimizing the experimental parameters.The prepared Cu₂O-RGO nanocomposite systems had excellent visible-light photocatalysis efficiency.Meanwhile,the mechanism of the enhanced photocatalytic activity caused by the synergistic effect between graphene and Cu₂O was proposed systematically for the first time.