化学学报 ›› 2004, Vol. 62 ›› Issue (12): 1110-1114. 上一篇    下一篇

研究论文

多价态共存的Ag-TiO2光催化剂的制备及光催化活性

辛柏福1, 井立强1,2, 任志宇1, 王健强1, 于海涛1, 付宏刚1   

  1. 1. 黑龙江大学化学化工与材料学院, 哈尔滨, 150080;
    2. 哈尔滨工业大学环境科学与工程系, 哈尔滨, 150001
  • 投稿日期:2003-08-19 修回日期:2004-02-20 发布日期:2014-02-17
  • 通讯作者: 付宏刚,E-mail:fuhg@vip.sina.com E-mail:fuhg@vip.sina.com
  • 基金资助:
    国家自然科学基金(Nos.20171016,20301006)、教育部重点项目计划(No.02051)、黑龙江省杰出青年科学基金(2002)、黑龙江省科学技术计划(No.WB02103)、黑龙江省自然科学基金(No.B0305)、黑龙江大学杰出科学基金(No.JC200308)资助项目.

Preparation and Activity of Ag-TiO2 Photocatalyst with Multi-valency State

XIN Bai-Fu1, JING Li-Qiang1,2, REN Zhi-Yu1, WANG Jian-Qiang1, YU Hai-Tao1, FU Hong-Gang1   

  1. 1. College of Chemistry and Chemical Engineering and Materials Science, Heilongjiang University, Harbin 150080;
    2. Department of Environmental Sciences and Engineering, Harbin Institute of Technology, Harbin 150001
  • Received:2003-08-19 Revised:2004-02-20 Published:2014-02-17

在避光条件下采用溶胶凝胶法制备了Ag-TiO2光催化剂,通过XRD,Raman,PL和XPS表征及对光催化降解罗丹明B的性能评价,发现Ag的掺入抑制了TiO2锐钛矿相的晶化,促进了TiO2由锐钛矿相向金红石相的转变.随着掺Ag量的增加,PL光谱强度下降,这说明Ag掺入抑制了光生电子空穴的复合.在较低掺杂浓度区(Ag/Ti atom<3%)以Ag+的迁移、扩散为主,在较高浓度掺杂区(Ag/Ti atom≥3%) Ag+的迁移、扩散和表面还原共存,在浅表层扩散阈值附近(Ag/Ti atom=3%~5%),Ag-TiO2光催化剂既有丰富的浅表层电子捕获阱,又有利于电子向表面还原态Ag的导出,使光生电子和空穴的复合得到有效的抑制,从而使光催化效率显著提高.当掺杂浓度大于阈值时,Ag-TiO2催化剂的催化活性降低.

关键词: 光催化, TiO2, 银, 制备

Ag-TiO2 catalysts with different contents of Ag were prepared by the sol-gel method in the absence of light. Through XRD, Raman, PL and XPS characterizations and activity evaluations of photocatalytic degradation of rhodamine B, it was found that the doped Ag promoted the phase transformation, but has a depression effect on the anatase grain growth. The PL intensity decreased with increasing of contents of Ag doping, suggesting that doped Ag inhibited recombination of photoinduced electrons and holes. In rather low doping concentration range (Ag/Ti atom3%) there are mainly migration and diffusion of Ag+ ions, and in rather high doping concentration range (Ag/Ti atom≥3%) migration and diffusion of Ag+ ions coexist with surface reductions. In the neighborhood of the shallow surface close to the diffusion threshold value (Ag/Ti atom=3%~5%), Ag-TiO2 catalysts have abundant shallow superficial layer electron traps and are favorable for the derivation towards Ag of superficial reduced state, leading to effective inhibition of recombination of photoinduced electrons and holes which significantly elevates the photocatalytic efficiency. When the silver dopant exceeded threshold value, the catalytic activity of Ag-TiO2 decreased.

Key words: photocatalysis, TiO2, Ag, preparation