掺杂纳米TiO_2光催化性能的研究

Photocatalytic Redox Activity of Doped Nanocrystalline TiO_2

利用浸渍法分别制备了Cr、Mn、Fe、Co、Ni、Cu六种过渡金属离子掺杂改性的二氧化钛光催化剂,以乙酸水溶液的光催化氧化反应和二氧化碳还原反应为探针,评价了掺杂催化剂的光催化性能.借助光电子能谱(XPS)、X射线衍射分析(XRD)等手段对掺杂催化剂进行了表征.研究结果表明,经过渡金属离子掺杂后,光催化性能均有不同程度的改善,改善程度按Cr、Co、Ni、Fe、Mn、Cu递增.掺杂后催化剂表面吸附氧的活泼性、金属离子的价态及得电子能力上的差异决定了不同离子掺杂纳米二氧化钛光催化性能的差异.

A set of nanometer TiO2 photocatalysts doped with various ions of transition metals (Cr?Mn?Fe?Co?Ni?and Cu) was prepared by using the wet impregnation method. The samples were characterized by using some bulk and surface techniques namely X ray diffraction (XRD) and X ray photoelectron spectroscopy(XPS). The samples were employed as catalysts for acetic acid photocatalytic oxidation degradation and carbon dioxide photocatalytic reduction in aqueous suspension, used as probe reactions. The characterization results have confirmed that the doping ions exist on the surface in the form of oxide and have no significant effect on crystal phase of the samples. Photocatalytic activities of the doped samples were improved in the order of Cr?Co?Ni?Fe?Mn?Cu. The photocatalytic activity of doped TiO2 appears to be a complex function of the dopant concentration, adsorption oxygen and the nature of doped ions.