A novel kind of magnetically separable photocatalyst of cerrium-doped mesoporous titanium dioxide coated magnetite （Ce/MTiO2/ Fe3O4） was prepared and its activities under UV and visible light were reported. The cata...A novel kind of magnetically separable photocatalyst of cerrium-doped mesoporous titanium dioxide coated magnetite （Ce/MTiO2/ Fe3O4） was prepared and its activities under UV and visible light were reported. The catalysts with Ce/MTiO2 shell and Fe3O4 core were prepared by coating photoactive Ce/MTiO2 onto a magnetic Fe3O4 core through the hydrolysis of tetrabutyltitanate （Ti（OBu）4, TBT） with precursors of ammonium ceric nitrate and TBT in the presence of Fe3O4 particles. The MTiO2 shell was for photocatalysis, the Fe3O4 core was for separation by the magnetic field and the doped Ce was used to enhance the photocatalytic activity of MTiO2. The morphological, structural and optical properties of the prepared samples were characterized by Bnmauer-Emmett-Teller （BET） surface area, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and UV-vis absorption spectroscopy. The effect of cerrium-doped content on the photocatalytic activity was studied and the result revealed that 0.5 mol.% Ce/MTiO2/Fe3O4 exhibited highest photoactivity. The photocatalytic activities of obtained photocatalysts under UV and visible light were estimated by measuring the degradation rate of methylene blue （MB, 50 mg/L） in an aqueous solution. The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photooxi- dation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, Ce/MTiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by an external magnetic filed. So, the photocatalyst can be reused without any mass loss. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.展开更多
Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray diffraction（XRD）, transmission el...Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray diffraction（XRD）, transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, and N2 adsorption-desorption isotherms confirms that the sample has a mesostructure with a higher specific surface area and shows that the mesoporous TiO2 spheres have a diameter of 2 μm, the average pore size is about 5.9 nm, and the BET surface area and specific pore volume are about 236 m2/g and 2.116 cm3/g, respectively. The anatase and rutile mesoporous TiO2 spheres calcined at 700 °C show much better photocatalytic activity than the samples calcined at other temperatures and is comparable to an uncalcined sample in the photodegradation of Methyl Blue（MB） under the UV irradiation.展开更多
基金Project supported by the National Natural Science Foundation of China (41073086)
文摘A novel kind of magnetically separable photocatalyst of cerrium-doped mesoporous titanium dioxide coated magnetite （Ce/MTiO2/ Fe3O4） was prepared and its activities under UV and visible light were reported. The catalysts with Ce/MTiO2 shell and Fe3O4 core were prepared by coating photoactive Ce/MTiO2 onto a magnetic Fe3O4 core through the hydrolysis of tetrabutyltitanate （Ti（OBu）4, TBT） with precursors of ammonium ceric nitrate and TBT in the presence of Fe3O4 particles. The MTiO2 shell was for photocatalysis, the Fe3O4 core was for separation by the magnetic field and the doped Ce was used to enhance the photocatalytic activity of MTiO2. The morphological, structural and optical properties of the prepared samples were characterized by Bnmauer-Emmett-Teller （BET） surface area, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and UV-vis absorption spectroscopy. The effect of cerrium-doped content on the photocatalytic activity was studied and the result revealed that 0.5 mol.% Ce/MTiO2/Fe3O4 exhibited highest photoactivity. The photocatalytic activities of obtained photocatalysts under UV and visible light were estimated by measuring the degradation rate of methylene blue （MB, 50 mg/L） in an aqueous solution. The results showed that the prepared photocatalyst was activated by visible light and used as effective catalyst in photooxi- dation reactions. In addition, the possibility of cyclic usage of the prepared photocatalyst was also confirmed. Moreover, Ce/MTiO2 was tightly bound to Fe3O4 and could be easily recovered from the medium by an external magnetic filed. So, the photocatalyst can be reused without any mass loss. It can therefore be potentially applied for the treatment of water contaminated by organic pollutants.
基金Supported by the National Natural Science Foundation of China(No.21076094)
文摘Mesoporous titanium dioxide spheres were synthesized by a convenient solvothermal method at room temperature with tetraethyl titanate as a precursor. Investigation by means of X-ray diffraction（XRD）, transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, and N2 adsorption-desorption isotherms confirms that the sample has a mesostructure with a higher specific surface area and shows that the mesoporous TiO2 spheres have a diameter of 2 μm, the average pore size is about 5.9 nm, and the BET surface area and specific pore volume are about 236 m2/g and 2.116 cm3/g, respectively. The anatase and rutile mesoporous TiO2 spheres calcined at 700 °C show much better photocatalytic activity than the samples calcined at other temperatures and is comparable to an uncalcined sample in the photodegradation of Methyl Blue（MB） under the UV irradiation.
文摘以四氯化钛为无机钛源,十六烷基三甲基溴化铵为模板剂,通过水热合成法制得无机物钛前驱体溶液.以导电碳毡(CCF)为载体,在超声波辅助下用浸渍提拉法负载钛前驱体,通过高温煅烧得到介孔二氧化钛/导电碳毡(MPT/CCF)光电极材料,对样品的结构进行了表征,并以室内污染物气相苯甲醛为目标降解物,通过评价不同煅烧温度和不同负载次数下MPT/CCF的光电催化性能优化了MPT/CCF的制备工艺条件,探讨了催化降解条件(温度、湿度、偏电压)对协同增效机制的影响.结果表明,相对于纯介孔二氧化钛(MPT),MPT/CCF具有较小的粒径尺寸、更大的比表面积和较均匀的孔径分布,这归功于CCF对晶粒生长的抑制作用.其中负载2次MPT并在500℃下煅烧的2-MPT/CCF-500样品具有最高的光电催化活性,主要是由于其具有完善的晶型、均匀的介孔分布和高浓度的羟基自由基,并且在重复使用过程中也具有很高的光电催化活性.最佳的催化条件为温度35℃、相对湿度55%、偏电压10 V.
