【摘要】 用混合溶胶 凝胶法制备了Fe3+,Zn2 +,Pd ,Co2 +,Ni2 +,Cr3+等金属离子掺杂的二氧化钛复合微粒。以四环素降解为目标反应 ,研究了所制备的复合微粒光催化活性与选择性。并用IR、XPS、Raman光谱等技术 ,探讨了影响复合微粒光催化活性的原因。结果显示 :掺杂Fe3+、Zn2 +的二氧化钛复合微粒对四环素降解具有很高的催化活性与选择性 ;掺杂Pd的复合微粒催化活性也有所提高。而Co2 +,Ni2 +,Cr3+等金属离子掺杂的二氧化钛复合微粒的催化活性呈下降趋势。研究认为 :Fe3+、Zn2 +促进二氧化钛微粒光催化活性的原因是由于这些金属离子高度分散在二氧化钛基质中 ,使基质晶型发生畸变并形成Ti O M桥氧结构 ;这种结构使复合微粒表面缺陷和活性比表面积增加 ,有利于光生载流子的转移。同时 ,Ti/Fe复合微粒中Fe3+有利于活性·OH基团的形成。这些活性·OH基团插入有机物的C H键中 ,最终导致有机物的完全降解矿化。另一方面 ,由于Fe3+,Zn2 +,Pd特殊的电子构型 ,有利于浅度捕获半导体的光生电子 ,使光生电子 空穴对有效分离。而Co2 +,Ni2 +,Cr3+金属离子的电子构型易深度捕获光生电子 ,结果可能形成了电子 空穴复合中心 ;导致半导体的量子效率和催化活性下降更多还原

【Abstract】 The titanium oxide complex particles doped Fe 3+ ,Zn 2+ , Co 2+ ,Ni 2+ ,Cr 3+ metal ions and Pd were prepared by mixed Sol gel method, and their catalytic reactivity ,selection for the photocatalytic degradation of an aqueous tetracyline were studied by UV vis,IR,XPS,Raman. It was found that photocatalytic reactivity of the TiO 2 particles doped Fe 3+ ,Zn 2+ ions were higher than that of the TiO 2 particles, which might be attributed to the highly dispersed metal ions on the TiO 2 matrix. These ions formed tetrahedrally coordinated Ti O M with the TiO 2 matrix and active ·OH. At the same time, the surface electron state of the complex particles was changed. Which increased the surface defect and the active specific surface of the TiO 2 complex particles. This might promote charge transform and efficiently divide the electrons and holes by shallowly traping electrons. But the photocatalytic reactivity of the TiO 2 particles doped Co 2+ ,Ni 2+ ,Cr 3+ ions were lower than that of the TiO 2 particles, which might be imputed to these metal ions depth trapped the photoilluminated electrons of the semiconductor particles.更多还原