Mechanism of silver modification for the enhanced photocatalytic activity of Cr(VI) reduction on TiO2 pholocatalyst

被引：9

作者：

Liu, SX

Sun, CL ^{[1
]}

机构：

[1] Chinese Acad Sci, Dalian Inst Chem Phys, Dalian 116023, Peoples R China

[2] NE Forestry Univ, Harbin 150040, Peoples R China

来源：

ACTA PHYSICO-CHIMICA SINICA | 2004年 / 20卷 / 04期

关键词：

silver; titanium dioxide; photocatalytic reduction; hexavalent chromium; mechanism;

D O I：

10.3866/PKU.WHXB20040404

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Under the condition that negative effects of proton starvation and photo-generated electron-hole recombination to the Cr6 + photocatalytic reduction process were minimized for the photocatalytic activities of TiO2 and Ag/TiO2 for Cr6 + reduction were comparatively investigated. Combined with the results of EPR, the mechanism of silver modification for the enhanced photocatalytic reduction of Cr6 + on TiO2 was discussed. The result revealed that Cr6 + reduction by the UV-Ag/TiO2 process was more effective than the UV-TiO2 process under the same conditions. Electron transfer from surface Ti3 + to Cr6 + was the key step for Cr6 + reduction. Cr6 + photocatalytic reduction by directly capturing photo-generated electrons is possible, but it occurs mainly indirectly by getting electrons from surface Ti3 +. The higher reduction activity of Ag/TiO2 photocatalyst came mainly from the higher number of surface Ti3 +.

引用

页码：355 / 359

页数：5

共 18 条

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AGNDO MA, 1991, CHEM ENG COMMUN, V104, P71

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