Publication Details (including relevant citation information):
A series of novel visible light-active photocatalysts of TiO2/CNT and PbS/CNT were prepared by simple wet-chemical method and the resulting materials were used for degradation of methyl orange (MO) as probe pollutant. The reactive substances used to decorate the PbS quantum dots (QDs) with the diameters of ca. 6–10 nm located onto the CNT substrate, were lead acetate (Pb(CH3COOH)) and Thiourea (NH2CSNH2) aqueous solution at 90 °C. The physic-chemical properties of the resulting photocatalysts were characterized by SEM-EDX, TEM, XRD, FTIR, and UV–vis DRS spectroscopy. It was found that the size, shape, and coverage density of the PbS QDs and TiO2 nanoparticles (NPs) onto the CNT can be controlled through varying synthesis conditions. As a result, the experiments demonstrated photodegradation efficiency of ∼100% of MO, for TiO2/CNT and PbS/CNT, under 20 and 45 min UV light irradiation time, respectively, and also 30 and 80 min under visible light irradiation time, respectively. In addition, the possible decomposing mechanisms were also discussed. The results of the current study showed the feasible and potential use of high efficient CNT:TiO2:PbS photocatalyst in photodecomposition of toxic organic pollutants. As the above-mentioned results show, the use of CNT in photocatalyst systems is not only enhances the optical properties of TiO2 and PbS photocatalysts, but also improve their capability in photodegradation of organic pollutants.
Address (URL): doi:10.1016/j.jtice.2013.01.018