The morphology of supported metal nanoparticles on TiO2/silical gel （TSO） and photothermal synergism were investigated for destruction of ethylene. During photocatalytic deposition of metal nanopartilces, the effect...The morphology of supported metal nanoparticles on TiO2/silical gel （TSO） and photothermal synergism were investigated for destruction of ethylene. During photocatalytic deposition of metal nanopartilces, the effects of pH and light intensity on the morphology of coated platinum, palladium, gold on TiO2/silical gel were studied. Moreover, these catalysts were characterized by TEM, UV-Vis DRS. The pH of preparing solution have strong influence on dispersion, size and sites of Pt, Pd and Au on TSO, which were controlled by the electrostatic binding of HPtCl5^- AuCl4^- and TiOH2^＋, Pd^2＋ and TiO^- respectively. Platinum, gold and palladium nanoparticles were uniformly highly dispersed on the titanol sites not silanol of TiO2/silical gel under pH=2, pH =9.9 respectively. For the photodegradation of ethylene, they show higher photothermal efficiency than those prepared with other pH conditions under UV illumination in a non-circulating photoreactor. The optimum weight loadings of Pt, Au, and Pd were 0.25 wt%, 0.5 wt%, 1 wt%, respectively. The synergistic effect enhanced ethylene removal and CO2 production. Thcse results verify that the best photothermal synergistic effect depends on the dispersion, size of noble metal nano-particles. FTIR analyses of the used Pt-, Pd-TSO catalysts indicated that no significant by-products were accumulated on the surface of the catalysts, leading to them longer lifetime.展开更多
It was proved that MgO and MicroSilica can react at room temperature, giving a hardened product primarily comprised of Mg （ OH ）2 and Magnesium Silicate Hydrate （ M- S- H ）. The reaction ratio and process and the ...It was proved that MgO and MicroSilica can react at room temperature, giving a hardened product primarily comprised of Mg （ OH ）2 and Magnesium Silicate Hydrate （ M- S- H ）. The reaction ratio and process and the chemical composion of M- S- H were studied and analyzed by QXRD and DTA- TG. The experimental results indicate that much Mg（ OH）2 and less M-S-H were formed at early period. After 7 days there is no change in the quantity of Mg（ OH）2, while M-S-H was increased slowly. The chemical composion of M-S-H would vary with the mix proportion in the hydrution process , but M1.32 SH2.37 is finally the approximute form.展开更多
文摘The morphology of supported metal nanoparticles on TiO2/silical gel （TSO） and photothermal synergism were investigated for destruction of ethylene. During photocatalytic deposition of metal nanopartilces, the effects of pH and light intensity on the morphology of coated platinum, palladium, gold on TiO2/silical gel were studied. Moreover, these catalysts were characterized by TEM, UV-Vis DRS. The pH of preparing solution have strong influence on dispersion, size and sites of Pt, Pd and Au on TSO, which were controlled by the electrostatic binding of HPtCl5^- AuCl4^- and TiOH2^＋, Pd^2＋ and TiO^- respectively. Platinum, gold and palladium nanoparticles were uniformly highly dispersed on the titanol sites not silanol of TiO2/silical gel under pH=2, pH =9.9 respectively. For the photodegradation of ethylene, they show higher photothermal efficiency than those prepared with other pH conditions under UV illumination in a non-circulating photoreactor. The optimum weight loadings of Pt, Au, and Pd were 0.25 wt%, 0.5 wt%, 1 wt%, respectively. The synergistic effect enhanced ethylene removal and CO2 production. Thcse results verify that the best photothermal synergistic effect depends on the dispersion, size of noble metal nano-particles. FTIR analyses of the used Pt-, Pd-TSO catalysts indicated that no significant by-products were accumulated on the surface of the catalysts, leading to them longer lifetime.
文摘It was proved that MgO and MicroSilica can react at room temperature, giving a hardened product primarily comprised of Mg （ OH ）2 and Magnesium Silicate Hydrate （ M- S- H ）. The reaction ratio and process and the chemical composion of M- S- H were studied and analyzed by QXRD and DTA- TG. The experimental results indicate that much Mg（ OH）2 and less M-S-H were formed at early period. After 7 days there is no change in the quantity of Mg（ OH）2, while M-S-H was increased slowly. The chemical composion of M-S-H would vary with the mix proportion in the hydrution process , but M1.32 SH2.37 is finally the approximute form.
