Enhanced Sonocatalytic Degradation of Rhodamine B by Graphene-TiO2 Composites Synthesized by an Ultrasonic-Assisted Method

A series of graphene-TiO2 composites was fabricated from graphene oxide and titanium n-butoxide (TNB) by an ultrasonic-assisted method. The structure and composition of the nanocomposites were characterized by Raman spectroscopy, BET surface area measurements, X-ray diffraction, transmission electron microscopy, and ultraviolet-visible absorption spectroscopy. The average size of the TiO2 nanoparticles on the graphene nanosheets was controlled at around 10–15 nm without using surfactant, which is attributed to the pyrolysis and condensation of dissolved TNB into TiO2 by ultrasonic irradiation. The catalytic activity of the composites under ultrasonic irradiation was determined using a rhodamine B (RhB) solution. The graphene-TiO2 composites possessed a high specific surface area, which increased the decolorization rate for RhB solution. This is because the graphene and TiO2 nanoparticles in the composites interact strongly, which enhances the photoelectric conversion of TiO2 by reducing the recombination of photogenerated electron-hole pairs.

Graphical abstractUltrasonic synthesis of graphene-TiO2 composites and their ability to degrade the organic dye rhodamine B under ultrasound irradiation are presented. The sonocatalytic activity of the graphene-TiO2 composites confirmed they were excellent catalysts because of the advantageous mechanical, thermal, optical and electrical properties of graphene.Figure optionsDownload full-size imageDownload as PowerPoint slide