阳极氧化膜WO_3(Ⅰ)——电显色和自褪色

WO_3 Anodic Oxide Film(Ⅰ)--Electrochromic and Auto-bleatching Processes

用循环伏安法、交流阻抗技术和光电流谱技术研究了阳极氧化膜WO_3电显色和自褪色过程的机理,电显色时,氢原子先在WO_3表面吸附,其后从WO_3表面向晶格内部传输,电褪色时,H_xWO_3晶格中填隙H原子先传输到W表面脱附生成填隙H^+,然后再在电场驱动下在膜中迁移,自褪色过程可能是由膜中所含的少量水和部分填隙H原子的羟基化作用引起的。

The electrochromic and auto- bleatching processes at the WO3 anodic oxide film in 0. 5 mol/L H2SO4 solution were studied by cyclic voltammetry, A. C. impedance technique and photocur-rent spectrbscopy. The coloration mechanism consists of hydrogen adsorption on the WO3 film surface and the transport of H atoms in the WO3 lattice. The bleatching process involves at least. transport of interstitial H atoms and hydrogen desdrption at the WOS film surface, resulting in interstitial H+ ions; then extration of H+ droven by the external electric field. The auto-bleatching is arised from hydroxy-lation due to both partial interstitial H atoms and the trace amount of water contained in the film.