Layer-by-layer deposition of open-pore mesoporous TiO2-Nafion® film electrodes
Layer-by-layer deposition of open-pore mesoporous TiO2-Nafion® film electrodes
复制标题
开孔介孔 TiO2-Nafion® 薄膜电极的逐层沉积
DOI：
10.1007/s10008-006-0247-3
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发表时间：
2007
影响因子：
2.5
通讯作者：
F. Marken
中科院分区：
文献类型：
--
作者：
Elizabeth V. Milsom;J. Novák;S. J. Green;Xiaohang Zhang;Susan J. Stott;R. Mortimer;K. Edler;F. Marken
通过逐层沉积工艺证明了具有开孔的可变厚度TiO 2纳米颗粒-Nafion ®复合膜的形成。直径约6 nm的TiO 2纳米颗粒的薄膜在Nafion®存在下通过纳米颗粒“聚集”成更大的聚集体而生长，并且所产生的分层结构以每个沉积循环约25 nm的厚度增厚。薄膜生长的特点是电子显微镜，原子力显微镜，石英晶体微天平技术。同时对煅烧前后的薄膜进行小角X射线散射和广角X射线散射测量，证明了Nafion®粘合剂引起聚集的效果。采用电化学方法来表征电荷通过TiO 2-Nafion®复合膜的导电性和扩散性。观察到固定在TiO 2-Nafion®纳米复合材料中的阳离子氧化还原体系（二庚基紫精2 +/+、$${\text{Ru}}{\left（{{\text{NH}}_{3} } \right）}^{{3 + /2 + }}_{6} $$和二茂铁基甲基-三甲基铵2 +/+）的特征电化学响应。电荷传导取决于氧化还原系统的类型，并建议通过直接传导通过TiO 2骨架（在足够负的电位）或通过基于氧化还原中心的扩散/电子跳跃（在更正的电位）发生。
The formation of variable thickness TiO2 nanoparticle-Nafion® composite films with open pores is demonstrated via a layer-by-layer deposition process. Films of about 6 nm diameter TiO2 nanoparticles grow in the presence of Nafion® by “clustering” of nanoparticles into bigger aggregates, and the resulting hierarchical structure thickens with about 25 nm per deposition cycle. Film growth is characterized by electron microscopy, atomic force microscopy, and quartz crystal microbalance techniques. Simultaneous small-angle X-ray scattering and wide-angle X-ray scattering measurements for films before and after calcination demonstrate the effect of Nafion® binder causing aggregation. Electrochemical methods are employed to characterize the electrical conductivity and diffusivity of charge through the TiO2-Nafion® composite films. Characteristic electrochemical responses are observed for cationic redox systems (diheptylviologen2+/+, $${\text{Ru}}{\left( {{\text{NH}}_{3} } \right)}^{{3 + /2 + }}_{6} $$, and ferrocenylmethyl-trimethylammonium2+/+) immobilized into the TiO2-Nafion® nanocomposite material. Charge conduction is dependent on the type of redox system and is proposed to occur either via direct conduction through the TiO2 backbone (at sufficiently negative potentials) or via redox-center-based diffusion/electron hopping (at more positive potentials).