高度分散的Pt/TiO_2的制备及光催化活性  

Preparation and the Enhanced Photocatalytic Activity of Highly Dispersed Pt Loaded on TiO_2 Nanocrystals

作　　者：张青红[1] 高濂[1] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《化学学报》2005年第1期65-70,F008,共7页Acta Chimica Sinica

基　　金：国家自然科学基金(No. 50372079);上海市科委纳米专项基金(No. 0352nm093)资助项目.

摘　　要：用柠檬酸作为空穴捕获剂和分散剂, 在温和条件下用光催化还原法将 3 nm 金属铂沉积在 7 nm 的锐钛矿相及介孔二氧化钛纳米晶表面. TEM 观察显示铂的负载量为 w=1.0%时, 多数二氧化钛纳米晶表面沉积了岛状的铂团簇, XPS和电子衍射结果表明铂以游离态存在. 负载 w=1.0%～2.0%铂的 TiO2在苯酚光氧化反应中活性显著提高. Pt/TiO2在氨气中经 550 ℃氮化, 可制得氮掺杂的 Pt/TiO2可见光光催化剂, 氮化过程中铂团簇没有烧结和显著长大.The metallic platinum clusters in size of 3 nm were photocatalytically deposited on anatase (7 nm) or mesoporous TiO2 in the presence of citric acid as a double-functional agent (a hole scavenger and a dispersant to keep Pt clusters from agglomeration). The particle size of the deposited platinum was uniform and in the range of 3similar to4 nm, and the surface of majority of TiO2 nanocrystals was deposited with an island of Pt cluster. Both XPS and ED results identified that the deposited Pt consisted of metallic atoms. The Pt/TiO2 showed a significantly enhanced photocatalytic activity using the degradation of phenol as a model reaction. The Pt/TiO2 was subjected to nitridation in the flowing NH3 at 550 and Pt-loaded TiO2-xNx nanocrystals were obtained. The particle size of Pt clusters was preserved and Pt clusters were not sintered at this temperature.

关 键 词：PT/TIO2 介孔 团簇 电子衍射 光催化活性 氮掺杂 氮化过程 分散剂 温和条件 制备 

分 类 号：O643.3[理学—物理化学]