Photoactivity of TiO2-Coated Pebbles

Development of immobilized TiO2 photocatalysts for solar photocatalytic degradation of organic pollutants is a technological need. In the present study, Degussa P-25 TiO2 photocatalyst was coated on pretreated pebbles and the photoactivity of TiO2/pebbles is reported for the first time. Three types of pebbles, i.e., black (B), red (R), and white (W), and a mixture (M) having equal proportions of B, R, and W, were chosen. The pretreatment of pebbles constituted washing with deionized water or leaching with EDTA solution. Coating of TiO2 on the pretreated pebbles was carried out as per the previously made titania powder (PMTP) method. X-ray powder diffractograms (XRD) of powdered pebbles and analysis for various metals in washings and leachates using an inductively coupled plasma-optical emission spectrometer (ICP-OES) and an atomic absorption spectrophotometer (AAS) were carried out. Solar photocatalytic decolorization of reactive black 5 (RB5) and some other reactive dyes was tested using TiO2/pebbles in ...