Study on the Enhancement of Efficiency, Photocatalytic Kinetics, and Mechanism of Trace GO on TiO₂ for Cr(VI) Removal Under Visible Light Conditions

This work focuses on the enhancement of removal performance of TiO₂ by the introduction of trace amout of GO composite. Among various synthesis methods, it was found that the GO–doped TiO₂ by microwave-assisted hydrothermal method had the highest performance in the improvement for Cr (VI) treatment. The removal rate of Cr (VI) by TiO₂–GO (0.05%) was 95.96% which is 13.58% higher than that of TiO₂. It can be confirmed that GO was successfully doped on TiO₂ by XRD, XPS, and FT-IR characterizations. In addition, SEM, TEM, N₂ adsorption isotherm, UV–Vis spectra, and photocurrent response elucidate the mechanism of potency enhancement. The addition of trace GO reduces the particle size of TiO₂ and results in the agglomeration phenomenon of TiO₂, so that the specific surface area of TiO₂ becomes larger and the distribution is more uniform, which expands the photoresponse range, and elevating the photoelectron response. Thus, the absorption ability of visible light is greatly improved. The reported method provides a more economical option for treating Cr(VI) wastewater.