Application Of Electrochromic Nanomaterials In Energy Storage And Biosensin

Electrochromism refers to the phenomenon that a class of materials undergo redox reaction and produce reversible color/optical changes under the action of an applied alternating electric field.Over the past few decades,electrochromic materials have been used in technologies ranging from smart windows to information displays and energy storage devices.The research focus and hotspot of electrochromic materials have changed to multifunctional and intelligent direction.However,the multi-directional development of this field is still in its infancy,with both opportunities and challenges.For example,the material system needs to be enriched,single device color,low device storage charge capacity and the structural design of the overall device needs to be optimized and improved.For the research and development of electrochromic nanomaterials in energy storage and biosensing,the main contents of this thesis are as follows:1.The hybrid material tungsten oxide(W₁₈O₄₉)_/polyaniline（PANI）with porous structure was synthesized by a simple and easy two-step method.Compared with pure PANI and W₁₈O₄₉films,the hybrid film shows excellent electrochemical and electrochromic properties.The composite film has high optical modulation（70.2%at652 nm）,large surface capacity(79.6 mF cm^-2)and good capacitor retention performance.The formation of donor（PANI）-acceptor(W₁₈O₄₉)pairs,the porous structure and large surface area in the W₁₈O₄₉nanowire substrate enhance the electron delocalization of W₁₈O₄₉/PANI,increase the ion diffusion rate and increase the charge storage site,thus giving it excellent charge storage capacity.In order to further explore the application of materials,magnesium（Mg）tablets and W₁₈O₄₉/PANI color changing electrode were combined to design electrochromic battery sustainable light red diode（LED）.The electrochromic device based on composite film assembly is colorful and has the function of self-bleaching without any external energy.The W₁₈O₄₉/PANI hybrid thin film electrochromic platform is expected to play an important role in electrochromic and energy storage due to its excellent optical,electrical and multifunctional characteristics.2.The enzymatic and electrochromic biosensing analysis method has the advantages of good selectivity and high sensitivity.However,the inherent shortcomings of natural enzymes such as high cost,poor stability and difficulty in recycling limit the practical application of enzyme biosensing.The hierarchical porous structure and excellent electrical conductivity of noble metal hydrogels are expected to achieve efficient enzyme fixation,improve the catalytic activity and stability of enzymes thanks to the affinity of the metal to the enzyme,and ultimately improve the detection performance of electrochromic biosensors.Herein,we designed a visual electrochromic biosensor based on AuCu noble metal hydrogel immobilized glucose oxidase（GOx）combined with Prussian blue（PB）electrochromic material.Due to the high catalytic activity and stability of the AuCu@GOx immobilized enzyme,and the excellent electrochromic properties and stability of PB,the visual glucose sensor is highly sensitive,selective,and reproducible.In addition,the dual-mode signal output of electrochemical method and visual mode can be used to realize fast and convenient glucose detection,glucose detection limit（LOD）of 0.82μM by visual mode and 0.84μM by electrochemical mode.The as-constructed visual platform based on AuCu@GOx and smartphone had a wide linear range,and good selectivity for glucose detection.This easy-to-operate electrochemical and visual detection platform with high accuracy for glucose detection,opens a door for the practical application of the multi-mode platform for glucose detection.