Preparation And Characterization Of Graphene-based Nanocomposites Photocatalyst

Nanomaterials are famous as "the most promising material of the 21st century". The research in nanomaterials has developed into an interdisciplinary science including physics, chemistry, materials and life science now. Graphene is a one atom thick and closely packed two-dimensional honeycomb-like lattice, has attracted great attention in both the experimental and theoretical scientific fields since it was found in 2004, due to the unique nanostructure and extraordinary properties, graphene based materials have shown promising applications in electronics, optics, magnetics, biomedicine, catalysis, sensors, energy storage etc. the photocatalysis technology is kown as a new technology in environmental protection with fine prospect, as a result of simple technology, low energy consumption, easy to control operating conditions and degradation of material thoroughly. This paper studies the photocatalyst/graphene nanocomposites. We have prepared three kinds of graphene nanocomposites through the different synthesis method, and systematically deeply studied their formation mechanisms, physics chemistry properties, photocatalytic properties especially. The major details and main results are given as follows:(1) we prepared the graphite oxide by Hummers method using nature graphite flakes, the graphene sheets were prepared via thermal exfoliation, or the exfoliated graphene oxide was prepared after the ultrasonic processing then reduced via chemistry method to the graphene sheets.(2) Successfully synthesized the TiO2/graphene nanocomposites via a sol-hydrothermal method for the first time using tetrabutyl titanate as the raw material of titanium and graphene as substrate. The synthesized products were systematically characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and Raman scattering. The results indicated that TiO2 has anatase structure with good state of crystallization, the nanocomposite facilitated photodegradation of Rhodamine B (RhB) due to the excellent adsorptivity, transparency, and conductivity of graphene. It is confirmed that the photocatalytic process of the TiO2/graphene nanocomposites followed first-order kinetics.(3) ZnO/graphene has been successfully synthesized via a sol route. The obtained products were systematically studied by XRD, SEM, TEM, HRTEM,Raman scattering and UV-vis absorption spectroscopy. RhB was acted as a representative pollutant to evaluate the photocatalytic efficiency of catalysts,the result is exhibit that the ZnO/graphene shown an fine photocatalytic activity in the photodegradation of RhB under visible light irridiation.(4) CdS/graphene has been successfully synthesized via a sol route. The obtained products were systematically studied by XRD, TEM, HRTEM and Raman scattering. RhB was acted as a representative pollutant to evaluate the photocatalytic efficiency of catalysts, the result is exhibit that the CdS/graphene shown an excellent photocatalytic activity in the photodegradation of RhB under visible light irridiation.