Ethanol supercritical route for fabricating bimodal carbon modified mesoporous TiO2 with enhanced photocatalytic capability in degrading phenol

This paper reports the fabrication of a novel mesoporous C-TiO2 photocatalyst via an ethanol supercritical solvothermal method involving tetrabutyl titanate and raw rice. Such as-prepared C-TiO2 possessed a bimodal carbon-modification effect, including carbon doping in the lattice of C-TiO2 and carbon sensitizing the surface of C-TiO2. The ethanol supercritical treatment also contributed mesoporous structure with large surface area (160 m(2)/g) and high crystallinity of anatase to the C-TiO2. These materials exhibited an excellent photocatalytic performance and recyclability for phenol oxidation under visible light irradiation (lambda > 420 nm). The C-TiO2 samples were characterized by using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature-programmed oxidation (TPO), Raman and ultraviolet-visible reflectance (UV-vis) spectroscopy. The relationship between the physicochemical property and the photocatalytic performance of the as prepared samples is discussed. We also investigate the effect of the supercritical temperature and calcining temperature on the photocatalytic performance of the obtained C-TiO2. The present work explores an effective supercritical fluid based route for the fabrication of mesoporous C-TiO2 with bimodal carbon modification effect and high photocatalytic performance for treating phenol, which can be extended to synthesize other functional photocatalytic materials. (C) 2011 Elsevier B.V. All rights reserved.