Ti O2是一种典型的半导体光催化材料,因具有较高的光催化活性、稳定性和较低的成本,在光催化领域有着潜在的应用价值。绝大多数已报道的纳米TiO2材料易团聚且光生电子空穴极易复合,大大限制了其在实际中的应用。MOFs高温下会使有机骨架...Ti O2是一种典型的半导体光催化材料,因具有较高的光催化活性、稳定性和较低的成本,在光催化领域有着潜在的应用价值。绝大多数已报道的纳米TiO2材料易团聚且光生电子空穴极易复合,大大限制了其在实际中的应用。MOFs高温下会使有机骨架热裂解,形成含大量的孔结构并暴露出活性位点的氧化物,用该方法制备的金属氧化物不仅比表面积较大,而且使金属氧化物高度分散在有机骨架裂解后的碳矩阵中,从而有效避免了纳米金属氧化物的团聚。重要的是,碳骨架可以传输光生电子,从而避免了光生电子和空穴的复合,大大提高了光催化效率。该文综述了近年来国内外对MOFs衍生制备TiO2材料及其应用的研究报道,着重介绍了含碳TiO2的设计合成与光催化应用研究进展,并对基于金属有机框架材料设计合成含碳氧化物及其光催化性能研究进行展望。展开更多
Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laborat...Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.展开更多
In this paper,the BaO-0.6ZnO-xTiO2 ceramics with x=2.5-2.8 have been prepared by the conventional solid-state ceramic route for the purpose of investigating the effect of TiO2 content on the microwave dielectric prope...In this paper,the BaO-0.6ZnO-xTiO2 ceramics with x=2.5-2.8 have been prepared by the conventional solid-state ceramic route for the purpose of investigating the effect of TiO2 content on the microwave dielectric properties.The XRD results showed that the main crystal phase in the sintered ceramics was Ba4ZnTi11O27 and that the additional phases:Ba2ZnTi5O13 and BaZn2.03Ti3.93O10.89 were presented,depending on the TiO2 contents.The SEM photographs of the samples sintered at 1200℃ for 2 h showed a high compact microstructure.Because the phase composition of ceramics samples was changed with TiO2 content,the dielectric constant(εr),the quality factor values(Q×f) and the temperature coefficient of resonant frequency(τf) were first increased,continuously came up to a peak value,and then let up.It was lucky to find that the sample with composition BaO-0.6ZnO-2.7TiO2 had both the maximum dielectric constant εr=36.1 and the maximum Q×f value of 29320 GHz,and more importantly,it had an acceptable temperature coefficient of resonant frequency τf=10.45 ppm/℃.展开更多
基金Project(2011CB201505)supported by the National Key Basic Research Program of ChinaProject(BA2011031)supported by the Special Fund of Transformation of Scientific and Technological Achievements of Jiangsu Province,China
文摘Nitric oxide(NO) from flue gas is hard to remove because of low solubility and reactivity. A new technology for photocatalytic oxidation of NO using ultraviolet(UV)/TiO2/H2O2 process is studied in an efficient laboratory-scale reactor. Effects of several key operational parameters on NO removal efficiency are studied, including TiO2 content, H2O2 initial concentration, UV lamp power, NO initial content, oxygen volume fraction and TiO2/H2O2 solution volume. The results illustrate that the NO removal efficiency increases with the increasing of H2O2 initial concentration or UV lamp power. Meanwhile, a lower NO initial content or a higher TiO2/H2O2 solution volume will result in higher NO removal efficiency. In addition, oxygen volume fraction has a little effect.The highest NO removal efficiency is achieved at the TiO2 content of 0.75 g/L, H2O2 initial concentration of 2.5 mol/L, UV lamp power of 36 W, NO initial content of 206×10-6 and TiO2/H2O2 solution volume of 600 m L. It is beneficial for the development and application of NO removal from coal-fired flue gas with UV/TiO2/H2O2 process.
文摘In this paper,the BaO-0.6ZnO-xTiO2 ceramics with x=2.5-2.8 have been prepared by the conventional solid-state ceramic route for the purpose of investigating the effect of TiO2 content on the microwave dielectric properties.The XRD results showed that the main crystal phase in the sintered ceramics was Ba4ZnTi11O27 and that the additional phases:Ba2ZnTi5O13 and BaZn2.03Ti3.93O10.89 were presented,depending on the TiO2 contents.The SEM photographs of the samples sintered at 1200℃ for 2 h showed a high compact microstructure.Because the phase composition of ceramics samples was changed with TiO2 content,the dielectric constant(εr),the quality factor values(Q×f) and the temperature coefficient of resonant frequency(τf) were first increased,continuously came up to a peak value,and then let up.It was lucky to find that the sample with composition BaO-0.6ZnO-2.7TiO2 had both the maximum dielectric constant εr=36.1 and the maximum Q×f value of 29320 GHz,and more importantly,it had an acceptable temperature coefficient of resonant frequency τf=10.45 ppm/℃.
