Construction And Properties Of WO₃/MoO₃-TiO₂/CdS Color-changing Device

How to realize the rational use of energy and the effective protection of the ecological environment has become a huge challenge in today’s society.Therefore,photochromic research has attracted wide attention.Photochromic devices made of typical electrochromic cathode material WO₃and photoanode material TiO₂have been widely used in smart windows,energy storage devices,displays and automotive rearview mirrors.How to prepare photochromic devices with better performance has become a research hotspot in recent years.In this paper,the main research objects are WO₃-MoO₃electrochromic cathode,TiO₂/CdS photoanode and WO₃/MoO₃-TiO₂/CdS photochromic device.The specific research contents are as follows:（1）WO₃nano-films were prepared on conductive glass（FTO）by hydrothermal method,and then WO₃-MoO₃thin films were prepared by hydrothermal method with different Mo doping ratios（0%,0.5%,1%,1.5%）.The structure and morphology of WO₃and WO₃-MoO₃thin film samples were characterized by XRD,SEM and EDS.The WO₃and WO₃-MoO₃thin film samples were tested by cyclic voltammetry,chronoamperometry,chronocoulometry,spectral transmittance and electronic impedance,and the results were analyzed in detail.The analysis results show that the reversibility,response time,optical modulation range and coloring efficiency of WO₃-MoO₃film samples are better than those of single WO₃nano-film.And the electrochromic properties of WO₃-MoO₃film samples doped with 1%Mo are the best.（2）TiO₂thin films were prepared on conductive glass（FTO）by hydrothermal method with changing the hydrothermal reaction time（2 h,3 h,4 h）.Then TiO₂/CdS composite films were prepared by continuous ion layer deposition.The structure and morphology of TiO₂/CdS composite films were characterized by XRD and SEM.The TiO₂/CdS composite film samples were tested by LSV,transient photocurrent,spectral transmittance and electronic impedance,and the results were analyzed in detail.The analysis results show that the TiO₂/CdS composite film samples with hydrothermal reaction for 3 h have the highest photoelectric conversion performance.（3）The WO₃-MoO₃film with the best electrochromic performance was selected as the cathode of the photochromic device,and the TiO₂/CdS composite film with the best photoelectric conversion performance was selected as the photoanode of the photochromic device.The open-circuit voltage,short-circuit current density,fill factor,energy conversion efficiency,response time,optical modulation range efficiency of WO₃/MoO₃-TiO₂/CdS photochromic device were tested by LSV,cyclic voltammetry and spectral transmittance,and compared with WO₃-TiO₂/CdS photochromic device.The results show that the performance of WO₃/MoO₃-TiO₂/CdS photochromic device is better than that of WO₃-TiO₂/CdS photochromic device.