Diffusion-limited transport of I- 3 through nanoporous TiO2-polymer gel networks.
Diffusion-limited transport of I- 3 through nanoporous TiO2-polymer gel networks.
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DOI：
10.1063/1.1812741
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发表时间：
2004-11
期刊：
影响因子：
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通讯作者：
M. Dürr;G. Kron;U. Rau;J. Werner;A. Yasuda;G. Nelles
中科院分区：
文献类型：
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作者：
M. Dürr;G. Kron;U. Rau;J. Werner;A. Yasuda;G. Nelles
通过简单的Pt-凝胶-Pt三明治结构器件的电流-电压（I-V）特性研究了三碘离子在纳米多孔TiO（2）网络中的输运及其扩散极限.在0.2和0.7 V之间的电压下，这种器件的I-V曲线显示出在铂电极处的扩散限制的氧化还原反应的典型平台，在这种情况下为I（-）/I（3）（-）。根据极限电流密度对层厚度的依赖性，三碘化合物在本体聚合物凝胶中和通过聚合物凝胶渗透的TiO（2）网络的扩散常数D（本体）和D（p，eff）分别被发现为D（本体）=3.2（+/-0.2）x10（-6）cm（2）/s和D（p，eff）=1.5（+/-0.1）x10（-6）cm（2）/s。依赖于温度的测量显示在凝胶中的扩散被激活约0.16 eV。结果进行了讨论，在液体电解质中的扩散比较，以及相对于染料敏化太阳能电池器件的影响。
Tri-iodide transport in a polymer gel electrolyte embedded in nanoporous TiO(2) networks and its diffusion limits are investigated by means of current-voltage (I-V) characteristics of simple Pt-gel-Pt sandwich devices with a thin porous TiO(2) layer sintered directly onto one of the Pt electrodes. At voltages between 0.2 and 0.7 V, the I-V curves of such devices show the typical plateau of diffusion-limited redox reactions, in this case I(-)/I(3) (-), at the platinum electrodes. From the dependence of the limiting current density on layer thickness, the diffusion constants D(bulk) and D(p,eff) of tri-iodide in the bulk polymer gel and through a polymer gel penetrated TiO(2) network, respectively, have been found to be D(bulk)=3.2(+/-0.2)x10(-6) cm(2)/s and D(p,eff)=1.5(+/-0.1)x10(-6) cm(2)/s. Temperature-dependent measurements show diffusion in the gel to be activated by about 0.16 eV. The results are discussed in comparison to diffusion in liquid electrolytes as well as with respect to the implications for dye-sensitized solar cell devices.