Yuhao Yang

Green and facile microwave-assisted synthesis of TiO2/graphene nanocomposite and their photocatalytic activity for methylene blue degradation

TiO2 (P25)/graphene nanocomposite photocatalyst have been successfully synthesized with P25 and different ratios of graphene oxide through a green and facile one-step microwave-assisted method. Graphene oxide was restored to graphene sheets and P25 was coated on it simultaneously during the reaction. The method offers easy access to the semiconductor/graphene nanocomposites with a uniform coating and strong interactions between semiconductor and the underlying graphene sheets. The prepared P25/graphene nanocrystals hybrid has superior photocatalytic activity in the degradation of methylene blue, showing an impressive photocatalytic enhancement over P25. The improved photocatalytic activities may be attributed to increased adsorptivity of dyes, extended light absorption range, and efficient charge separation properties of a two-dimensional graphene network.

Hydrothermal synthesis of Graphene-TiO2 nanowire with an enhanced photocatalytic activity

The hydrothermal method was used to synthesize TiO2 nanowire (NW) and then fabricate graphene-TiO2 nanowire nanocomposite (GNW). Graphene oxide (GO) was prepared via improved Hummers’method. GO reduction to graphene and hybridization between NW and graphene by forming chemical bonding. The as-prepared composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM), and ultraviolet visible (UV-Vis) diffuse reflectance spectra. The photocatalytic activity was evaluated by the photodegradation of methylene blue (MB). The prepared GNW nanocomposite has superior photocatalytic activity in the degradation test, showing an impressive photocatalytic enhancement over NW. At the same time, in comparison with Graphene-TiO2 nanoparticle (NP) nanocomposite (GNP), GNW have a better activity which because NW have more uniform dispersion on graphene with less agglomeration.