Efficient photoinduced conversion of an azo dye on hexachloroplatinate(IV)-modified TiO2 surfaces under visible light irradiation-A photosensitization pathway.
Efficient photoinduced conversion of an azo dye on hexachloroplatinate(IV)-modified TiO2 surfaces under visible light irradiation-A photosensitization pathway.
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DOI：
10.1002/chem.200204559
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发表时间：
2003-07
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通讯作者：
Wei Zhao;Chuncheng Chen;Wanhong Ma;Jincai Zhao;Dianxun Wang;H. Hidaka;N. Serpone
中科院分区：
文献类型：
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作者：
Wei Zhao;Chuncheng Chen;Wanhong Ma;Jincai Zhao;Dianxun Wang;H. Hidaka;N. Serpone
研究了P-25 TiO（2）颗粒表面化学吸附的六氯铂（IV）阴离子（PtCl（6）（2-））对可见光照射下Pt（IV）/TiO（2）分散体系中偶氮染料乙基橙子（EO）光诱导转化的影响。自旋陷阱电子自旋共振（ESR）光谱结果，形成的有机过氧化物的量的测量，总有机碳（TOC）和化学需氧量（COD（Cr））测定，以及XPS证据表明，由Pt（IV）/TiO（2）介导的EO染料的自敏化转化动力学比那些发生在裸TiO（2）在可见光照射的其他相同条件下快得多。X射线光电子能谱数据还表明，在所使用的实验条件下，在可见光照射期间，没有Pt（0）在二氧化钛颗粒上形成。我们提出了一种反应机理，其中在PtCl（6）（2-）存在下EO的更快转化主要是由染料的光激发引起的，而不是由四氯铂酸盐（IV）/TiO（2）颗粒的局部激发引起的。
The titanium dioxide photocatalyst is employed to examine the influence of chemisorbed hexachloroplatinate(IV) anions (PtCl(6) (2-)) on the surface of P-25 TiO(2) particles on the photoinduced conversion of the azo dye Ethyl Orange (EO) in visible light-illuminated Pt(IV)/TiO(2) dispersions. Spin-trap electron spin resonance (ESR) spectral results, measurement of quantities of organoperoxides formed, total organic carbon (TOC) and chemical oxygen demand (COD(Cr)) assays, together with XPS evidence show that the self-sensitized transformation dynamics of the EO dye mediated by Pt(IV)/TiO(2) are much faster than those occurring on naked TiO(2) under otherwise identical conditions of visible light irradiation. X-ray photoelectron spectral data also show that under the experimental conditions used, no Pt(0) formed on the titania particles during visible light irradiation. We propose a reaction mechanism in which the more rapid conversion of EO in the presence of PtCl(6) (2-) is caused principally by photoexcitation of the dye and not by localized excitation of the tetrachloroplatinate(IV)/TiO(2) particles.