The synergistic effect of H_3PMo_(12)O_(40) or H_3PW_(12)O_(40) polyoxometalate solution(POM) and TiO_2 to catalyze formic acid oxidation was investigated. Under UV irradiation, hole and electron were photogenerated b...The synergistic effect of H_3PMo_(12)O_(40) or H_3PW_(12)O_(40) polyoxometalate solution(POM) and TiO_2 to catalyze formic acid oxidation was investigated. Under UV irradiation, hole and electron were photogenerated by TiO_2. Formic acid was oxided by the photogenerated hole and photogenerated electron was transferred to reduce polyoxometalate. With this design, formic acid can be converted into electricity in the fuel cell and hydrogen can be generated in the electrolysis cell without noble metal catalyst. Unlike other noble metal catalysts applied in the fuel cells and electrolysis cell, POM and TiO_2 are stable and low cost. The maximum output power density of liquid formic acid fuel cell after 12 h UV irradiation is 5.21 mW/cm^2 for phosphmolybdic acid and 22.81 m W/cm^2 for phosphotungstic acid respectively. The applied potential for the hydrogen evolution is as low as 0.8 V for phosphmolybdic acid and 0.6 V for phosphotungstic acid.展开更多
A series of mesoporous materials （H3PW12O40/TiO2, Y-H3PW12O40/TiO2 and La-H3PW12O40/TiO2） were prepared by a modified sol-gel-hydrothermal route, which realized the load and modification of H3PW12O40 at the same tim...A series of mesoporous materials （H3PW12O40/TiO2, Y-H3PW12O40/TiO2 and La-H3PW12O40/TiO2） were prepared by a modified sol-gel-hydrothermal route, which realized the load and modification of H3PW12O40 at the same time. The prepared samples were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR）, nitrogen adsorption-desorption analysis, ultraviolet-visible absorption spectrum （UV-Vis） and scanning electron microscopy （SEM）. The XRD and FT-IR results displayed that the catalysts had uniform anatase phase and the primary Keggin structure of H3PW12O40 remain intact. Nitrogen ad-sorption-desorption analysis suggested that suitable doping of rare earth elements could increase the specific surface area from 177.9 m2/g （H3PW12O40/TiO2） to 229.5 （1 wt.%Y-H3PW12O40/TiO2） or 236.1 m2/g （1 wt.%La-H3PW12O40/TiO2）. Results of UV-Vis spectra showed that the band of the 1 wt.%Y-H3PW12O40/TiO2 and 1 wt.%La-H3PW12O40/TiO2 have an obvious redshift compared with the H3PW12O40/TiO2. Additionally, the composites were used as heterogeneous photocatalysts to the degradation of dinitrotoluene （DNT）. It is the first time that polyoxometalate （POM） is applied in the degradation of explosive wastewater.展开更多
基金supported by the Shanghai Committee of Science and Technology,China(12DZ2275100) Centre National de la Recherche Scientifique,France and Universitéde Strasbourg,France~~
文摘The synergistic effect of H_3PMo_(12)O_(40) or H_3PW_(12)O_(40) polyoxometalate solution(POM) and TiO_2 to catalyze formic acid oxidation was investigated. Under UV irradiation, hole and electron were photogenerated by TiO_2. Formic acid was oxided by the photogenerated hole and photogenerated electron was transferred to reduce polyoxometalate. With this design, formic acid can be converted into electricity in the fuel cell and hydrogen can be generated in the electrolysis cell without noble metal catalyst. Unlike other noble metal catalysts applied in the fuel cells and electrolysis cell, POM and TiO_2 are stable and low cost. The maximum output power density of liquid formic acid fuel cell after 12 h UV irradiation is 5.21 mW/cm^2 for phosphmolybdic acid and 22.81 m W/cm^2 for phosphotungstic acid respectively. The applied potential for the hydrogen evolution is as low as 0.8 V for phosphmolybdic acid and 0.6 V for phosphotungstic acid.
基金Institution of Chemical Materials, China Academy of Engineering Physics for financial support
文摘A series of mesoporous materials （H3PW12O40/TiO2, Y-H3PW12O40/TiO2 and La-H3PW12O40/TiO2） were prepared by a modified sol-gel-hydrothermal route, which realized the load and modification of H3PW12O40 at the same time. The prepared samples were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR）, nitrogen adsorption-desorption analysis, ultraviolet-visible absorption spectrum （UV-Vis） and scanning electron microscopy （SEM）. The XRD and FT-IR results displayed that the catalysts had uniform anatase phase and the primary Keggin structure of H3PW12O40 remain intact. Nitrogen ad-sorption-desorption analysis suggested that suitable doping of rare earth elements could increase the specific surface area from 177.9 m2/g （H3PW12O40/TiO2） to 229.5 （1 wt.%Y-H3PW12O40/TiO2） or 236.1 m2/g （1 wt.%La-H3PW12O40/TiO2）. Results of UV-Vis spectra showed that the band of the 1 wt.%Y-H3PW12O40/TiO2 and 1 wt.%La-H3PW12O40/TiO2 have an obvious redshift compared with the H3PW12O40/TiO2. Additionally, the composites were used as heterogeneous photocatalysts to the degradation of dinitrotoluene （DNT）. It is the first time that polyoxometalate （POM） is applied in the degradation of explosive wastewater.
