The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis ...The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis diffuse reflection spectroscopy, surface photovoltage spectroscopy (SPS). The activities of TiO2 and Gd3+-doped TiO2 catalysts for photocatalytic degradation of ethylene were studied by means of in situ FTIR. The photocatalytic reaction rate constant of ethylene becomes larger through Gd3+ doping. The rate constant of TiO2 was k1=8.51×10-4 min-1, while that of Gd/TiO2 was k2=1.85×10-3 min-1. At the same time, the yield of CO2 increased with Gd3+ doping. The enhancement in photocatalytic activity is probably due to the increase of light absorption, higher content of anatase, smaller crystal line size and higher specific surface area. In addition, the higher photocatalytic activity of Gd3+-doped TiO2 might be attributed to the effective separation of photo-generated electron-hole pairs.展开更多
The source of urban atmospheric particles is broad, and the major source is the building dust from urban construction. Calcium is the tagged element and Portland cement is the major com- ponent of building dust. In th...The source of urban atmospheric particles is broad, and the major source is the building dust from urban construction. Calcium is the tagged element and Portland cement is the major com- ponent of building dust. In this study, CaO was regarded as the representative oxide of building dust, and mixtures were synthesized in terms of the major element ingredients of building dust. The het- erogeneous uptake of SO2 on CaO, mixtures, Portland cement and building dust samples was inves- tigated. In situ FTIR and X-ray photoelectron spectroscopy (XPS) were used to identify the products of the reactions. In addition, the crystal phases and the surface properties of the samples were charac- terized by XRD patterns and BET specific surface area. The results show that in the presence of oxygen, sulfur dioxide can be adsorbed to sulfite and further catalytically oxidized to sulfate on the surface of CaO, the mixtures, Portland cement and building dust. The reactivity of SO2 on the surface of dust and oxides is basically a first order. The main ingredient of building dust sample is SiO2, and the one of Portland cement is Ca3SiO5.展开更多
The electro-oxidation of formaldehyde on a gold electrode in a gold electrode in a solution containing0.1mol ·L -1 Na2 CO3＋0. 1mol·L - 1NaHCO3＋0. 1 mol·L, - 1 HCHO was investigated bycyclic voltammetr...The electro-oxidation of formaldehyde on a gold electrode in a gold electrode in a solution containing0.1mol ·L -1 Na2 CO3＋0. 1mol·L - 1NaHCO3＋0. 1 mol·L, - 1 HCHO was investigated bycyclic voltammetry and in -situ FTIR spetroscopy . The experimental results demonstrated that the oxidation of formaldehyde at different potential range connected with different surface species of gold. At lower potentials, the main product of formaldehyde oxidationwas HCOO-, and at higher potentials, the products HCOO- and CO2 were detected simultaneously. From the results, a possible reaction mechanism was proposed.展开更多
文摘The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis diffuse reflection spectroscopy, surface photovoltage spectroscopy (SPS). The activities of TiO2 and Gd3+-doped TiO2 catalysts for photocatalytic degradation of ethylene were studied by means of in situ FTIR. The photocatalytic reaction rate constant of ethylene becomes larger through Gd3+ doping. The rate constant of TiO2 was k1=8.51×10-4 min-1, while that of Gd/TiO2 was k2=1.85×10-3 min-1. At the same time, the yield of CO2 increased with Gd3+ doping. The enhancement in photocatalytic activity is probably due to the increase of light absorption, higher content of anatase, smaller crystal line size and higher specific surface area. In addition, the higher photocatalytic activity of Gd3+-doped TiO2 might be attributed to the effective separation of photo-generated electron-hole pairs.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 20377008).
文摘The source of urban atmospheric particles is broad, and the major source is the building dust from urban construction. Calcium is the tagged element and Portland cement is the major com- ponent of building dust. In this study, CaO was regarded as the representative oxide of building dust, and mixtures were synthesized in terms of the major element ingredients of building dust. The het- erogeneous uptake of SO2 on CaO, mixtures, Portland cement and building dust samples was inves- tigated. In situ FTIR and X-ray photoelectron spectroscopy (XPS) were used to identify the products of the reactions. In addition, the crystal phases and the surface properties of the samples were charac- terized by XRD patterns and BET specific surface area. The results show that in the presence of oxygen, sulfur dioxide can be adsorbed to sulfite and further catalytically oxidized to sulfate on the surface of CaO, the mixtures, Portland cement and building dust. The reactivity of SO2 on the surface of dust and oxides is basically a first order. The main ingredient of building dust sample is SiO2, and the one of Portland cement is Ca3SiO5.
文摘The electro-oxidation of formaldehyde on a gold electrode in a gold electrode in a solution containing0.1mol ·L -1 Na2 CO3＋0. 1mol·L - 1NaHCO3＋0. 1 mol·L, - 1 HCHO was investigated bycyclic voltammetry and in -situ FTIR spetroscopy . The experimental results demonstrated that the oxidation of formaldehyde at different potential range connected with different surface species of gold. At lower potentials, the main product of formaldehyde oxidationwas HCOO-, and at higher potentials, the products HCOO- and CO2 were detected simultaneously. From the results, a possible reaction mechanism was proposed.
