Reduced Graphene Oxide-TiO2 Nanocomposite Facilitated Visible Light Photodegradation of Gaseous Toluene

摘要

The photocatalytic degradation of gaseous toluene was investigated on TiO2 nanoparticles coated on reduced graphene oxide. Reduced graphene oxide-TiO2 composite (RGO-TiO2) was synthesized via two step processes. The prepared RGO-TiO2 composite was characterized using SEM, XRD, and UV-visible spectra. A significant increase in light absorption to visible light was observed by RGO-TiO2 compared with that of pure TiO2 nano particles. The photocatalytic degradation efficiency of the RGO-TiO2 composite was much higher than that of the P25 TiO2, 95% and 40% respectively. In our investigated conditions, the initial concentration, flow rate and relative humidity had significant influences on the photocatalytic degradation of gaseous toluene. The most efficiency was recorded at the 0.3 ppm concentration, 1L/min flow rate and 30% relative humidity. We believe that this TiO2 based composite material can be effectively used as a highly active and stable photocatalyst to remove various indoor air pollutants especially gaseous toluene. The photocatalytic degradation efficiencies of toluene increased slowly below 20% relative humidity and then decreased as the relative humidity increased further. The main reason of enhanced photocatalytic property might be the strong electron transfer ability, and the increased adsorption capacity of RGO sheets in the composites as well as the retarded charge recombination rate contributed by the energy level of the two materials. We believe that this TiO2 based composite material can be effectively used as a highly active and stable photocatalyst to remove various gaseous pollutants.