The low temperature synthesis and characterization of cobalt(9)sulfur(8), nickel(3)sulfur(2), and zinc sulfide and study of the photocatalytic property of titanium dioxide

Three sulfide compounds, {dollar}{lcub}rm Cosb9Ssb8, Nisb3Ssb2{rcub},{dollar} and ZnS, have been prepared by the decomposition of their respective diethyldithiocarbamate complexes. The products were characterized by X-ray diffraction analysis, crystallite size determination, and magnetic susceptibility measurements. The problems associated with organometallic precursors for the synthesis of metal sulfides are discussed and the method is compared with the direct conversion of sulfides in a controlled H{dollar}sb2{dollar}/H{dollar}sb2{dollar}S environment.; Thin films of zinc sulfide were prepared by ultrasonically spraying a toluene solution of bis(diethyldithiocarbamato)zinc (II) onto silicon, sapphire and gallium arsenide substrates at 460-520{dollar}spcirc{lcub}rm C{rcub}.{dollar} The films prepared on silicon or sapphire were found to have a highly oriented hexagonal structure, while those deposited onto cubic (100) gallium arsenide showed a highly oriented cubic structure. The films were characterized by X-ray diffraction analysis, ellipsometry, scanning electron microscopy, and IR spectroscopy.; Samples of the {dollar}{lcub}rm Nbsb2Osb5/TiOsb2{rcub}{dollar} mixed oxide powders were prepared by incipient wetness method. The photocatalytic activities of TiO{dollar}sb2{dollar} based catalysts were evaluated by the degradation of 1,4-dichlorobenzene (DCB). The addition of {dollar}{lcub}rm Nbsb2Osb5{rcub}{dollar} to TiO{dollar}sb2{dollar} greatly increased its photocatalytic activity. The addition of {dollar}{lcub}rm Nbsb2Osb5{rcub}{dollar} TiO{dollar}sb2{dollar} also increased the catalyst's surface acidity, as determined by the n-butylamine titration method. A correlation between the maximum photocatalytic activity and the maximum surface acidity was observed. Acidity may not be the only factor which influences activity, it is certainly an important one.; TiO{dollar}sb2{dollar} thin films were prepared by spin coating and spray pyrolysis techniques. The observed photocatalytic activity is the same for films prepared by both techniques. The photocatalytic activity increases as film thickness increases but remains constant after the thickness reaches 0.60 {dollar}mu{dollar}m. These films are shown to be capable of photodecomposing organic impurities in water.