Study On The Discoloration Properties Of TiO₂/WO₃ Composite Films

Electrochromic materials have become a research hotspot in recent years due to their broad application prospects in intelligent energy-saving windows,automotive anti-glare rearview mirrors,low-energy display,and military materials.In this dissertation,TiO2,WO3and TiO2/WO3 inorganic electrochromic materials were the main research objects.The modification of the materials was studied by the composite of TiO2 nanowire films and WO3nanowire films.The purpose is to improve the insufficiency of the optical modulation range,slow response speed,and poor cycle performance of a single inorganic color changing material.The main research work is as follows:The hydrothermal method was used to grow TiO₂ nanowires on FTO conductive glass substrates.The effects of hydrothermal duration and heat treatment temperature on the electrochromic properties of TiO2 nanowire films were investigated.The electrochromic performances of the films were measured by cyclic voltammetry and chronoamperometry using an electrochemical workstation.The optical properties of the film were measured using an ultraviolet spectrophotometer.The results show that the TiO2 nanowires with the hydrothermal duration of 10h TiO2 nanowires and the annealing temperature of 250°C have the best electrochromic properties.The WO₃ nanowires were grown on FTO conductive glass substrates by hydrothermal method,and the effect of hydrothermal duration on the electrochromic properties of WO3nanowire films were studied.The electrochromic performances of the films were measured by cyclic voltammetry and chronoamperometry using an electrochemical workstation.The optical properties of the films were measured using an ultraviolet spectrophotometer.The results show that the hydrothermal duration of 6h WO3 nanowires has the best electrochromic properties.TiO2 nanowires were prepared on FTO by hydrothermal method.Then WO3 nanowires were prepared on TiO2 nanowires by hydrothermal method to obtain TiO2/WO3 composite films.The electrochromic performance of the films was measured by cyclic voltammetry and chronoamperometry using an electrochemical workstation.The optical properties of the films were measured using an ultraviolet spectrophotometer.It is found that the TiO2/WO3composite film samples show the higher ion insertion/extraction capability,excellent cycle life,faster response speed,greater optical modulation range and coloring efficiency compare to the single films.