Visible Light Photocatalysis with Platinized Rutile TiO2 for Aqueous Organic Oxidation
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- 作者：Bo Sun ; Panagiotis G. Smirniotis ; and P. Boolchand
- 刊名：Langmuir
- 出版年：2005
- 出版时间：November 22, 2005
- 年：2005
- 卷：21
- 期：24
- 页码：11397 - 11403
- 全文大小：232K
- 年卷期：v.21,no.24(November 22, 2005)
- ISSN：1520-5827
文摘
Platinized rutile TiO2 samples containing varying concentrations of Pt were synthesized using Kemira(KE, BET surface area 50 m2/g, from Finland), and Toto HT0270 (HT, BET surface area 2.9 m2/g, fromJapan) as the starting materials by solution mixing followed by sintering the precursors. Photocatalyticactivities were established for phenol oxidation under visible light (wavelength >400 nm). Our resultsshow optimal performance for 8 wt % platinized KE (8 wt % Pt/KE) and 1/2 wt % platinized HT rutilesamples. The specific roles of O2 and visible light were examined using the 8 wt % Pt/KE sample in eitherN2 gas ambient or no illumination. Separately, 8 wt % platinized SiO2 was tested to compare its performancewith that of platinized rutile TiO2. Several other chemicals containing different functional groups (formicacid, salicylic acid, 4-chlorophenol, 2,4,6-trichlorophenol, diethyl phosphoramidate) were selected forphotooxidation tests with 1/2 wt % platinized HT rutile. X-ray diffraction reveals Pt metal clusters segregatingon the surface of rutile TiO2 particles with increasing Pt weight percent. The Pt cluster surface areabroadly increases, while the effective optical band gap steadily decreases with platinization of the rutilesamples. These results suggest that Pt clusters on the surface of rutile TiO2 particles serve to mediateelectron transfer from rutile to O2, thus facilitating photooxidation of organic chemicals.