Construction of nanocomposite film of Dawson-type polyoxometalate and TiO2 nanowires for electrochromic applications

This paper shows a nanocomposite film of Dawson-type polyoxometalate (POM) K 6 P 2 W 18 O 62 (P 2 W 18 ) and TiO 2 nanowires by combining hydrothermal and Layer-by-Layer (LbL) assembly methods The electrochemical and electrochromic (EC) performances were examined and compared with P 2 W 18 and TiO 2 composite film as well as individual P 2 W 18 and TiO 2 structures. The nanocomposite film exhibits improved EC properties with high transmittance modulation (45.1% at 650   nm), fast switching times (1.9   s and 6.7   s) and outstanding coloration efficiency (69.0   cm 2 /C at 650   nm). The enhancement can be attributed to the contribution from P 2 W 18 and TiO 2 , which displays large real active area and increase the capabilities for EC material.