Synthesis of TiO2/graphene Oxide Nanocomposite and its Application for Visible Light Assisted Photocatalytic Degradation of Crystal Violet Dye

The photocatalysts based on the nanocomposite of TiO2 and x% graphene oxide (TiO2/GO-x) (x = 1, 3, 5, 8 and 10) have been successfully synthesized by a solvethermal method. The nanocomposites were characterized using XRD, SEM, EIS, UV-Visible spectroscopy and photocatalytic analyses. The XRD and SEM analyses indicated that the nanosheets of GO were completely incorporated by TiO2 NPs in the solvethermal process. Results of EIS analysis demonstrated a lower resistance for carrier transfer between the TiO2/GO modified electrode and the electrolyte. Study on the optical properties of the samples using UV-Visible spectroscopy revealed that the optical band gaps of TiO2, TiO2/GO-1, TiO2/GO-3, TiO2/GO-5, TiO2/GO-8 and TiO2/GO-10 were obtained as 3.27, 3.15, 3.10, 3.05, 3.03 and 2.98 eV, respectively, indicating the narrowing of the band gap with increased GO content in nanocomposite. The photocatalytic results for degradation of 100 mg/l crystal violet (CV) dye aqueous solution containing 5 mg of photocatalysts showed that the high degradation rate and complete removal of dye were achieved in the presence of TiO2/GO-8 photocatalyst after 90 and 80 minutes of irradiation of UV and visible light, respectively, indicating the optimum content of GO in TiO2/GO based-photocatalyts under both of UV and visible light irradiations was evaluated 8%. Comparison between the photocatalytic degradation performance of TiO2/GO-8 nanocomposite and the other reported literature for treatment CV dye illustrated that the TiO2/GO-8 nanocomposite had effective performance for degradation of CV dye because of the large specific surface area, high adsorption capacity and high photocatalytic activity under UV and visible light irradiations.

Automated summary

The study successfully synthesized photocatalysts based on the nanocomposite of TiO2 and graphene oxide (TiO2/GO-x). The nanocomposites showed excellent photocatalytic degradation performance, with TiO2/GO-8 exhibiting the best performance under both UV and visible light irradiation.