A study of photocatalytic graphene–TiO2 synthesis via peroxo titanic acid refluxed sol

• TiO2 synthesized via PTA as a precursor demonstrates exclusively anatase phase.
• The TEM image of GR–TiO2 (PTA) demonstrates that TiO2 nanoparticles are successfully loaded onto graphene sheet.
• The specific surface area seems to increase with increasing weight ratio of graphene oxide. It was observed that GR–TiO2 showed higher adsorption compared to bare TiO2 (PTA).
• The GR–TiO2 (PTA, 1:50) catalyst showed higher photocatalytic activity than any other catalyst.

In the present work, graphene–TiO2 (GR–TiO2) photocatalyst with various weight ratios of graphene was synthesized using peroxo titanic acid solution (PTA) as a precursor for TiO2. Graphene oxide prepared by Hummer's method was converted to graphene under ultraviolet (UV) irradiation in ethanol–water solvent for 48 h. The as-prepared GR–TiO2 composites were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV–vis spectrophotometry, and transmission electron microscopy (TEM). The automated potentiostat was applied to measure the photocurrent generations of prepared catalysts. The photocatalytic activities of GR–TiO2 (PTA) catalysts were determined by measuring the percentage methylene blue (MB) degradation. The results showed that TiO2 nanoparticles were successfully loaded onto graphene sheet and the surface area of catalysts increased with increasing weight ratio of graphene. In addition, GR–TiO2 (PTA, 1:50) exhibited the highest photocatalytic activity among the catalysts under UV and visible light irradiation. The adsorption edge of GR–TiO2 was shifted to a longer wavelength of 400 nm in comparison with that of pure TiO2 (PTA). The increase in the photocatalytic performance of GR–TiO2 (PTA) catalyst may be attributed to the increase in surface area, the extension of light absorption in the visible light region, and prevention of charge recombination.

Figure optionsDownload as PowerPoint slide