采用溶胶-凝胶浸渍法和光沉积法制备了系列Pt/RE/TiO₂纳米光催化剂, 通过XRD和电化学等手段进行了表征. 以甲醛为电子给体, 考察了光催化剂在紫外光照射下的制氢活性. 稀土掺杂提高了Pt/TiO₂光催化制氢活性, 其顺序分别为La/TiO₂>Sm/TiO₂>Eu/TiO₂>Dy/TiO₂>Er/TiO₂. 掺入稀土元素后, 阻止了TiO₂从锐钛矿晶型向金红石晶型的转变, 这是光催化剂活性提高的原因之一. 计算晶格畸变应力e数据表明, Ti⁴⁺可能反掺入了表面稀土氧化物的晶格中. 电化学实验表明稀土掺杂TiO₂的平带电位负移, 其原因可解释为晶格畸变促使费米能级升高, 导致催化剂导带的平带电位负移, 因此导带上被激发电子具有更强的还原能力, 从而有利于光催化制氢活性的提高.

A series of Pt/RE/TiO₂ photocatalysts were prepared by sol-gel impregnation and photodepositon process, and characterized by means of X-ray diffraction and electrochemistry. As a model reaction, photocatalytic hydrogen generation from water using formaldehyde as electron donor was investigated. It has been found that the activities of all rare earth doped TiO₂ samples have been increased compared to those of pure TiO₂, and the order was La/TiO₂＞Sm/TiO₂＞Eu/TiO₂＞Dy/TiO₂＞Er/TiO₂. It was shown that the transformation from anatase to rutile was prevented, which could enhance the activities of the photocatalysts. The data of lattice distortion implied that Ti⁴⁺ could enter (anti-dope) into rare earth oxide that existed on the surface of titanium dioxide. The data of electrochemistry experiment showed that the flat-band potential of conduction of RE/TiO₂ has been shifted negatively. The lattice distortion raised the Fermi level, which caused flat-band potential of the conduction of TiO₂ to shift negatively. As a result, the photoinduced electrons of the conduction band had stronger reductive capability and the photocatalytic activity of hydrogen generation was improved.