Kinetics of coloration of anodic electrochromic films of WO3·H2O
Kinetics of coloration of anodic electrochromic films of WO3·H2O
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DOI：
10.1007/bf00615491
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发表时间：
1980-09
影响因子：
2.9
通讯作者：
C. Sunseri;F. Quarto;A. Paola
中科院分区：
文献类型：
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作者：
C. Sunseri;F. Quarto;A. Paola
在70° C下，在1 N H2SO 4中对钨进行阳极氧化，得到了WO 3·H2O多晶层。这些层在酸性溶液中的阴极还原导致蓝色WO 3 −x·H2O（0<x <$：0.12）氧化物的形成。用恒电流和恒电位技术研究了着色动力学。实验结果进行了比较，通过求解扩散方程的氧空位的恒定流量和随时间变化的表面空位浓度的理论数据。除了在着色的初始阶段，工艺控制速率可以归因于氧空位从氧化物-电解质界面扩散到大部分层中。在低空位浓度下，氧化物-电解质界面上的势垒限制质子转移似乎决定了着色的动力学。
Polycrystalline layers of WO3·H2O are obtained by anodization of tungsten in 1 N H2SO4at 70° C. The cathodic reduction of these layers in acid solutions causes the formation of blue WO3−x·H2O (0<x⩽:0.12) oxides. The kinetics of coloration are investigated by galvanostatic and potentiostatic techniques. The experimental results are compared with the theoretical data obtained by solving the diffusion equation for a constant flow of oxygen vacancies and for a time-dependent surface vacancy concentration. Except in the initial stage of coloration, the process controlling rate can be ascribed to the diffusion of oxygen vacancies from the oxide-electrolyte interface into the bulk of the layers. At low vacancy concentration, a barrier-limited proton transfer across the oxide-electrolyte interface seems to determine the kinetics of coloration.