Titania modified nanoparticles have been prepared by the photodeposition method employing platinum particles on the commercially available titanium dioxide (Hombikat UV 100). The properties of the prepared photocatalysts were investigated by means of the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-visible diffuse spectrophotometry (UV-Vis). XRD was employed to determine the crystallographic phase and particle size of both bare and platinised titanium dioxide. The results indicated that the particle size was decreased with the increasing of platinum loading. AFM analysis showed that one particle consists of about 9 to 11 crystals. UV-vis absorbance analysis showed that the absorption edge shifted to longer wavelength for 0.5% Pt loading compared with bare titanium dioxide. The photocatalytic activity of pure and Pt-loaded TiO2was investigated employing the photocatalytic oxidation and dehydrogenation of methanol. The results of the photocatalytic activity indicate that the platinized titanium dioxide samples are always more active than the corresponding bare TiO2for both methanol oxidation and dehydrogenation processes. The loading with various platinum amounts resulted in a significant improvement of the photocatalytic activity of TiO2. This beneficial effect was attributed to an increased separation of the photogenerated electron-hole charge carriers.

In this paper, the reactive yellow 14 dye solution was removed from aqueous solution in the presence of commercial ZnO (mean crystallite size is 44.116 nm) under the UV A light. The decolourization of dye process was obeyed to pseudo-first orderkinetics. The optimum conditions of decolourization for this dye such as: initial dye concentration 50 mg/L, best dose of ZnO 350 mg/100mL and initial pH of aqueous solution of dye 6.75 were studied. Activation energies for dye were found to be 27.244 kJmol −1. The photoreaction process was observed to be endothermic reaction and less randomness.

The aim of this manuscript was to modify the ZnS surface by incorporating with CdS photocatalyst. This manner led to depressing the recombination process and increasing the activity. The X-ray Powder Diffraction (XRD) data were proved that the CdS incorporated with ZnS and formed ZnS-CdS nanocomposite by observing new peaks at 26.92, 28.62, 30.52, and 47.26°. Based on the Atomic Force Microscopy (AFM) analysis and Tauc equation, the particle sizes for all samples were raised with decreased the band gap values. The activation energy for decolorization of Congo red with the using ZnS is found to be more than that value for the using prepared ZnS-CdS composite. The percentage of efficiency was found to be increased with modified the ZnS surface.

No abstract

No abstract