Improvements in the life of WO3 electrochromic films

Abstract

The life of Nation-coated WO₃ electrochromic films in 0.5 mol dm ^–3H₂SO₄ was studied by cyclic voltammetry and in situ UV spectrophotometry and compared with uncoated films. The presence of Nation film at the electrode surface restricted the diffusion of tungsten ions to the bulk electrolyte, thereby significantly prolonging the life of the electrodes. This technique should find useful applications to other catalytic electrodes in aqueous media.