TiO2 nanoparticles incorporated with graphite particles: An efficient photocatalyst for the photocatalytic reduction of Cr(VI) ions in aqueous solution

摘要

TiO_2 nanoparticles incorporated with carboxyl-modified graphite (Graphite-COOH) were prepared in a solvothermal process. By comparison with TiO_2 nanoparticles (Degussa P25), the TiO_2 nanoparticles incorporated with Graphite-COOH display higher photocatalytic activity with 98% of reduction efficiency of Cr(VI) ions after 1.5 hours ultraviolet (UV) irradiation. In order to investigate the effect of the graphite particles on the photocatalytic activity of TiO2 nanoparticles, diffuse reflectance UV-vis spectra (DRS), and photocurrent-potential curves were measured. The results indicate that the enhanced photocatalytic activity may be ascribed to the easier migration of photogenerated electrons to the TiO_2 surface because of the introduction of graphite.