Design Of Fluorescence Switch Based On Electrochromic System

In recent years,electrochromic materials exhibit considerable application potential in information display devices,smart windows,as well as in fields such as electrocatalysis,photochemistry,energy storage,photocatalysis,and photochromism.By combining the electrochromic and fluorescent materials,the obtained fluorescence switches based on electrochromism are of great significance.In this dissertation,PANI/Eu-MOF thin film,electrochromic fluorescent hydrogel and the corresponding device,and Eu-WO₃thin film were prepared and constructed as electrochromic fluorescence switch system.The morphology,elemental composition,and structural characterization of the prepared materials were analyzed by characterizations like scanning electron microscopy,X-ray diffraction,Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy.The optical properties of the prepared films,hydrogels,and devices were tested by UV-Vis spectrophotometry,electrochemical workstation,and fluorescence spectrophotometry.Firstly,PANI/Eu-MOF thin films were successfully prepared by a multi-step electrodeposition method.The prepared films showed fluorescence switching behavior by changing the applied voltage.Secondly,stretchable and self-repairable electrochromic fluorescent hydrogels based on multiple cross-linked networks were prepared using a two-step polymerization method,and the assembled devices could regulate the fluorescence switch by changing the applied voltage.Finally,Eu-WO₃thin film as electrochromic fluorescence switch was successfully fabricated on ITO glass substrate by hydrothermal method.The color and fluorescence of the thin film could be modulated by changing the applied voltage.The three prepared electrochromic fluorescence switches could achieve tunable fluorescence switching behavior by controlling the applied voltage,showing possible potential applications in smart windows and next-generation smart displays.