Grinding (solvent-free) method was used as a superior technique to prepare mesoporous photocatalysts of ZnO, ZnS, ZnO / ZnS, CDO, CdS and CDO / CdS-SBA-15. In this technique, the nitrate, acetate and chloride salts of zinc and/or cadmium were grinded with as-synthesized SBA-15 as a mesoporous material. The controllable sulfurationis was used to prepare ZnS, ZnO/ZnS, CdS and CDO/CdS-SBA-15 at temperature of 80oC. The advantages of grinding technique were: i) the elimination of solvent and thus decrease of expense and ii) the complete incorporation of metal salts in the nanochannel of mesoporous material in a short time. X-ray powder diffraction, N2 adsorption-desorption and FT-IR spectroscopy were used to characterize the prepared materials. The highly dispersed semiconductors in SBA-15 demonstrate an active photodegradation of Congo red in aqueous solution. The nanocomposites of ZnO/ZnS and CDO/CdS in channels of SBA-15 showed the highest photocatalytic activity. The photocatalytic activity of ZnO-, ZnS- and ZnO/ZnS-SBA-15 were also dependent on the salt precursor of zinc. The prepared composite photocatalysts of zinc/SBA-15, by using ZnCl2 as salt precursor, indicated the higher activity.

Cadmium oxide (CDO) thin films were deposited on the glass substrate by the modified SILAR method, using cadmium acetate dihydrate and ammonium hydroxide aqueous solution as precursors. The structural, surface morphological, elemental composition and optical properties of the deposited films were investigated via X-Ray Diffraction (XRD), scanning electron microscopy, EDAX, optical absorption, photo luminescence and FT-IR spectroscopy. The XRD analysis reveals that the films were polycrystalline with cubic structure. Both crystallinity and grain size were found to increase with increasing solution concentration. The energy-dispersive spectroscopic analysis confirmed the presence of Cd and O elements. The films exhibited a maximum transmittance (50%-70%) in the infra-red region. Transmittance was found to increase with increasing precursor concentration and estimated band gap energy (Eg) was in the range of 2. 17 – 2. 21 eV.

Template synthesis is a powerful method for the preparation of nanoscale materials with specific size and shape. Cadmium oxide (CDO) nanoparticles were prepared by using sodium dodecyl sulfate (SDS), Cd(OAc)2.2H2O and sodium hydroxide as starting materials. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The XRD pattern proves that the final product has cubic phase and the particle size diameter of the nanoparticles are 36.4 nm. The SEM was used for direct visualization of the size and shape of the nanoparticles. The morphology of the CDO was found nanospherical. Antibiotics are a major class of drugs included in the designation of emerging contaminants, representing a high risk to natural ecosystems. We studied the degradation of Sulfathiazole antibiotic by nanosized CDO under ultraviolet irradiation. Various experimental parameters such as initial Sulfathiazole (STZ) concentrations, initial CDO concentration and initial pH were investigated. According to the results this method can be good performance in removal of Sulfathiazole.