Preparation, characterisation and electrochromic property of mesostructured tungsten oxide films via a surfactant templated sol-gel process from tungstic acid

A novel kind of mesoporous tungsten oxide films (TOFs) has been prepared via a non-ionic surfactant templated sol-gel route from cheap and easy handling tungstic acid. Characterisations by means of various techniques, including XRD, TEM, SEM, ATR and DTA, confirm that the obtained mesostructures are composed of fine mesopores (2-3 nm) and thin pore walls. Compared with previously reported surfactant templated mesoporous TOFs, our initial evaluation on the electrochromic properties showed that the derived TOFs show greatly enhanced colouration efficiency of 44 cm²C^-1 and faster colouration/bleaching speed of 10/2 s, respectively. Owing to the ordering of mesostructures delivered by our method, the mesostructural changes associated with the electrochemical reaction during the electrochromic cycling of such materials can be directly monitored by low-angle XRD measurements.