1. A series of nanometer TiO_2 photocatalysts doped respectively by elements with atomic number from 23 to 30 were prepared. 以沉淀法制备得到了第一过渡系23至30号元素(V，Cr，Mn，Fe，Co，Ni，Cu，Zn)分别掺杂的纳米TiO_2光催化剂。