ULTRAFAST STUDY OF INTERFACIAL ELECTRON TRANSFER BETWEEN 9-ANTHRACENE-CARBOXYLATE AND TIO2 SEMICONDUCTOR PARTICLES
ULTRAFAST STUDY OF INTERFACIAL ELECTRON TRANSFER BETWEEN 9-ANTHRACENE-CARBOXYLATE AND TIO2 SEMICONDUCTOR PARTICLES
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9-蒽羧酸盐与二氧化钛半导体颗粒之间界面电子转移的超快研究
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
P. Kamat
中科院分区：
文献类型：
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作者：
I. Martini;J. Hodak;G. Hartland;P. Kamat
以250fs的时间分辨率研究了9-蒽-羧酸吸附在TiO2半导体颗粒表面的激发态动力学。瞬态吸收和时间分辨各向异性测量的结合表明，大约76%的光激发染料分子将电子转移到TiO2颗粒上。确定了正向电子转移反应的时间尺度为≤1 ps。该反应产生的9-蒽羧酸自由基阳离子在54ps的时间尺度上进行反向电子转移。由于被吸附的染料分子没有将电子转移到TiO2上，因此对正向电子转移反应时间的更准确估计是不可能的。这些非活性物质通过非辐射衰变或荧光发射而失活。与TiO2颗粒结合的染料分子的荧光光谱与溶液中的游离染料的荧光光谱非常不同。游离染料…
The excited state dynamics of 9-anthracene-carboxylic acid adsorbed onto the surface of TiO2 semiconductor particles were examined with ca. 250 fs time resolution. A combination of transient absorption and time-resolved anisotropy measurements show that approximately 76% of the photo-excited dye molecules transfer an electron to the TiO2 particles. The time scale for the forward electron transfer reaction was determined to be ⩽1 ps. The 9-anthracene-carboxylate radical cations produced by this reaction undergo back electron transfer on a 54 ps time scale. A more accurate estimate of the forward electron transfer reaction time is not possible, due to the contribution to the transient absorption signal from adsorbed dye molecules that do not transfer electrons to TiO2. These nonreactive species are deactivated by either nonradiative decay or fluorescence emission. The fluorescence spectrum from the dye molecules bound to the TiO2 particles is very different to that of the free dye in solution. The free dye ...