| Polycrystalline samples of members of the systems (ZnS){dollar}sb{lcub}rm 1-x{rcub}{dollar}(CuMS{dollar}sb2)sb{lcub}rm x{rcub}{dollar} (M = Al, Ga, In, or Fe) were prepared by the direct combination of the elements. The significant difference in physical properties between CuMS{dollar}sb2{dollar} (M = Al, Ga, or In) and CuFeS{dollar}sb2{dollar} was miscibility with ZnS. CuFeS{dollar}sb2{dollar} was the only chalcopyrite compound which contained a magnetic ion. This fact can account for the difference in physical properties between CuMS{dollar}sb2{dollar} (M = Al, Ga, or In) and CuFeS{dollar}sb2{dollar}. Single crystals of members of the systems (ZnS){dollar}sb{lcub}rm 1-x{rcub}{dollar}(CuMS{dollar}sb2)sb{lcub}rm x{rcub}{dollar} (M = Al, Ga, In, or Fe) (nominal composition, x = 0, 0.05, 0.1) were grown by chemical vapor transport using iodine as the transport agent. They all crystallized with the zinc blende structure. Their IR transmission range is narrower than that observed for pure ZnS, but all, except for the ZnS-CuInS{dollar}sb2{dollar} system, still showed good transmission in the long wavelength IR range. The addition of small amounts of I-III-VI{dollar}sb2{dollar} compound modified the hardness and the thermal stability of ZnS. Polycrystalline samples of (ZnSe){dollar}sb{lcub}rm 1-x{rcub}{dollar}(CuMSe{dollar}sb2)sb{lcub}rm x{rcub}{dollar} (M = Al, Ga, or In) were also prepared by the direct combination of the elements. The IR transmission range of single crystals, grown by chemical vapor transport, was narrower than that observed for pure ZnSe. However, these materials still showed good transmission in the long wavelength IR range. The addition of small amounts of CuMSe{dollar}sb2{dollar} (M = Al, Ga, or In) increased the hardness of ZnSe.; Samples of WO{dollar}sb3{dollar}/TiO{dollar}sb2{dollar} mixed oxide powders were prepared by two methods: the incipient wetness impregnation of an aqueous ammonia solution of H{dollar}sb2{dollar}WO{dollar}sb4{dollar} onto TiO{dollar}sb2{dollar} (P25), followed by heat treatment and the ultrasonic nebulization and flame hydrolysis of a mixed isopropanol solution of tungsten (V) pentaethoxide and titanium (IV) tetraisopropoxide. The photocatalytic activities of TiO{dollar}sb2{dollar}-based catalysts were evaluated by the degradation of 1,4-dichlorobenzene (DCB). The addition of WO{dollar}sb3{dollar} to TiO{dollar}sb2{dollar} greatly increased its photocatalytic behavior. This may be related to an increase in the transfer of electrons from the TiO{dollar}sb2{dollar} to the outer system, via the formation of a intermediate W(V) species. |
