物理化学学报 >> 2013, Vol. 29 >> Issue (07): 1566-1571.doi: 10.3866/PKU.WHXB201304284

催化和表面科学 上一篇    下一篇

锐钛矿(001)与(101)晶面在光催化反应中的作用

王翔1,2, 李仁贵1,2, 徐倩1, 韩洪宪1, 李灿1   

  1. 1 中国科学院大连化学物理研究所, 催化基础国家重点实验室, 洁净能源国家实验室(筹), 辽宁 大连 116023;
    2 中国科学院大学, 北京 100049
  • 收稿日期:2013-04-03 修回日期:2013-04-28 发布日期:2013-06-14
  • 通讯作者: 李灿 E-mail:canli@dicp.ac.cn
  • 基金资助:

    国家自然科学基金(21090341, 21061140361)资助项目

Roles of (001) and (101) Facets of Anatase TiO2 in Photocatalytic Reactions

WANG Xiang1,2, LI Ren-Gui1,2, XU Qian1, HAN Hong-Xian1, LI Can1   

  1. 1 State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, Dalian 116023, Liaoning Province, P. R. China;
    2 Graduate University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2013-04-03 Revised:2013-04-28 Published:2013-06-14
  • Contact: LI Can E-mail:canli@dicp.ac.cn
  • Supported by:

    The project was supported by the National Natural Science Foudaton of China (21090341, 21061140361).

摘要:

采用水热法制备了(001)和(101)晶面暴露的单晶锐钛矿TiO2颗粒. 利用光还原沉积贵金属(Au, Ag, Pt)和光氧化沉积金属氧化物(PbO2, MnOx)的方法研究了暴露的锐钛矿(001)和(101)晶面在光催化中的作用. 通过透射电子显微镜(TEM)、扫描电子显微镜(STM)、能量色散X射线光谱仪(EDX)和X射线光电子能谱(XPS)的表征, 发现发生光还原反应生成的贵金属粒子主要沉积在暴露的锐钛矿(101)晶面上, 而发生光氧化反应产生的金属氧化物颗粒主要沉积在暴露的锐钛矿(001)晶面上. 此结果表明光激发产生的电子与空穴主要并分别分布在单晶锐钛矿TiO2的(101)与(001)晶面上, 并在其上参与光催化还原反应和氧化反应. 同时也表明暴露的不同晶面对光生电荷具有分离效应. 基于本研究可以认为同时暴露分别进行氧化和还原反应的晶面可以有效促进光催化反应.

关键词: TiO2, 锐钛矿, 光催化, 晶面, 电荷分离

Abstract:

Single crystals of anatase TiO2 with exposed (001) and (101) facets were synthesized by a hydrothermal method. We carried out photocatalytic reduction reactions to deposit noble metals (Au, Ag, and Pt) and photocatalytic oxidation reactions to deposit metal oxides (PbO2 and MnOx) on the surface of TiO2. The deposited anatase TiO2 samples were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) to study the roles of the two facets of anatase TiO2 in photocatalytic reactions. The noble metals were selectively deposited on the exposed (101) facet, while metal oxides were selectively deposited on the exposed (001) facet. This result indicated that photogenerated electrons and holes mainly accumulated on the (101) and (001) facets, and then took part in photocatalytic reduction and oxidation reactions, respectively. These results also suggested that the simultaneous exposure of the two facets could facilitate charge separation. Therefore, it was proposed that the simultaneous exposure of two facets with different functions will be a new strategy to effectively promote photocatalytic reaction.

Key words: TiO2, Anatase, Photocatalysis, Crystal facet, Charge separation

MSC2000: 

  • O643