In this paper, TiO₂-partially reduced graphene oxide (TiO₂-PRGO) nanocomposites were successfully fabricated by a modified one-step solvothermal method and the photocatalytic effect was investigated in experiments. Its photocatalytic efficiency for methylene blue (MB) degradation was maximum seven times than that of pure TiO₂ nanoparticles.

The effect of graphene oxide with different reduction degrees on the photocatalytic efficiency of titanium dioxide-graphene (TiO₂-G) composites has not been systematically studied. In this paper, titanium dioxide-partially reduced graphene oxide (TiO₂-PRGO) nanocomposites were prepared by a modified one-step solvent-thermal method and further reduced with ascorbic acid to obtain TiO₂-PRGO(xh) with a higher degree of reduction (ascorbic acid 80° reduced TiO₂-PRGO x h, x = 1, 2, 3, 4). The composites were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible diffuse reflectance spectroscopy (DRS). The transient photocurrent response and electrochemical impedance results show that TiO₂-PRGO has the most outstanding photoelectrochemical properties. Compared with pure TiO₂ and other samples, the TiO₂-PRGO nanocomposites exhibited excellent photocatalytic properties, and their photocatalytic efficiencies for the degradation of methylene blue (MB) were up to seven times higher than those of the pure TiO₂ nanomaterials, and twice that of TiO₂-PRGO(4h). The photodegradation of methylene blue by the composites decreased as the degree of PRGO reduction increased. The efficient photocatalytic performance of TiO₂-PRGO can be attributed to the high TiO₂ loading and good electrical conductivity. Notably, TiO₂-PRGO photocatalysis for 90 min resulted in 100% degradation of MB. Meanwhile, TiO₂-PRGO has good reusability, and the degradation rate of TiO₂-PRGO remained at 95% after four times of degradation in MB solution.