The Performance of Electrochromic Tungsten Trioxide Films Doped with Cobalt or Nickel

Tungsten trioxide is being developed as a electrochromic material for smart windows. However, the relatively high electrical resistivity and overpotential for hydrogen evolution and oxidation affect their response time and electrical power consumption. Previous work on indicated that admixing of Pt onto significantly reduced the over‐potential for hydrogen oxidation and evolution reactions since the formation of hydrogen tungsten bronze results in the "spill‐over" of the hydrogen reaction to the tungsten bronze surface. This paper reports work on the preparation of code‐posited and films which give significantly faster response times and consumes less power than traditional films.