【作者】 李毅；

【导师】 杨亚杰；

【作者基本信息】 电子科技大学 ， 光学工程， 2024， 博士

【摘要】 近些年,导电聚合物（Conducting polymers,CPs）与其它领域的交叉融合催生了多种新兴的电化学器件与应用,其中包括气体传感器、生物传感器、电化学储能器件等。然而这些电化学器件目前仍面临着化学信息自主加载机制不明确、微尺度能量转换效率低、特定界面状态设计和调节困难等问题,严重阻碍其发展。聚吡咯（polypyrrole,PPy）具有可被氧化还原和电荷转移特征明显等化学特性,将其与纳米结构材料相结合构筑形态及性能可调复合纳米材料及器件,可实现电化学器件性能的多功能化及性能提升。本论文针对电化学气敏及生物传感器、超级电容器等电化学器件灵敏度较低、循环稳定性较差、储能密度低等问题,利用PPy与多种纳米结构复合,通过合成工艺优化、形貌结构调控策略来提升电化学器件的性能。采用材料表征分析与理论研究相结合,探究了PPy复合纳米材料特性对多种电化学器件性能的影响,并对材料及器件的相关机理进行了阐述,论文主要研究内容如下:（1）针对制备简单、成本低廉、稳定耐用氨气传感器所面临的问题和挑战,采用原位聚合技术,在聚氨酯海绵上调控PPy材料的生长,制备了具有多级微纳结构的气敏材料,并对其进行了表征。研究了聚氨酯海绵孔隙以及多巴胺（Dopamine,PDA）对PPy与海绵的粘附性的影响。研究结果发现通过引入PDA可以有效增强PPy与海绵的聚合效果,单位体积内PPy的聚合填充量得到明显提高;进一步基于PPy-聚氨酯材料构筑了电阻式氨气传感器并研究了其气敏性能,研究结果表明该传感器对NH₃表现出良好的响应特性和湿度稳定性。（2）研发了一种基于PPy原位修饰碳纳米管（Carbon Nano Tube,CNT）的高灵敏、便携式汗液乳酸传感器。利用表面改性和低温聚合,构建了均匀包覆的CNT-PPy复合纳米材料。研究了Py单体浓度和聚合时间对PPy负载量及CNT-PPy复合材料电阻率的影响,并对不同聚合时间和浓度的CNT-PPy纳米材料的结构、成分、微观形貌进行表征分析。探究了CNT-PPy纳米材料的乳酸响应电流受温度、PH等参数的影响;进一步设计了基于智能手机的实时人体运动过程乳酸分泌监控和报警系统。该研究结果展示了基于CNT-PPy复合纳米材料乳酸传感器在健康与安全防护领域的潜在应用。（3）针对金属有机框架（Metal–inorganic framework,MOF）材料存在的导电性差、稳定性差的问题,通过简单的一步水热法构筑了结构稳定的PPy/Co-MOF三维分级多孔材料,并以其为电极制备了非对称型超级电容器。对复合材料的微观形貌、结构及官能团等进行了详细的表征,同时结合电化学测试手段对材料的电化学性能进行了详细的分析。研究结果显示Co-MOF/PPy电极具有较高的比容量和良好的循环伏安特性。在此基础上组装的非对称超级电容器具有较好的能量密度和功率密度,为高性能超级电容赝电容电极材料的构筑提供了新思路。更多还原

【Abstract】 In recent years,the cross-fusion of conductive polymers and other fields has given rise to a variety of emerging electrochemical devices and applications,including gas sensors,biosensors,and electrochemical energy storage devices.However,these electrochemical devices are still faced with some problems,such as unclear autonomous loading mechanism of chemical information,low efficiency of micro-scale energy conversion and difficulty in designing and adjusting specific interface states,which seriously hinder the development of electrochemical sensors.The conductive polymer,polypyrrole(PPy),has the excellent chemical properties of redox process and charge transfer.Combining it with nanostructured materials can form composite nanomaterials and devices with adjustable structures and properties,which can achieve multifunctional and improved performances of electrochemical devices.Aimed at solving the problems of low sensitivity,poor recycling stability,and low energy storage density for electrochemical devices,such as electrochemical gas and biosensors as well as supercapacitors,this dissertation synthesized the conductive polymer PPy with various kinds of nanomaterials through optimization of synthesis processes and regulation of structures to enhance the performance of electrochemical devices.The effect of composite nanomaterials synthesized based on the conductive polymer PPy upon the performance of electrochemical devices was studied through the combined approach of materials characterization analysis and theoretical research,and relevant mechanisms concerning such materials and devices were explained.The research content and results of this dissertation are as follows:(1)In order to prepare ammonia sensors with simple preparation,low cost as well as good stability and durability,in situ polymerization technology was used to regulate the polymerization time of PPy materials on polyurethane sponge,and the gas sensitive material with multi-level micro-and nano-structure was successfully synthesized and characterized.The effect of polyurethane sponge pores and Dopamine(PDA)on the adhesion of PPy to sponge was studied.The results showed that the polymerization effect of PPy and sponge could be effectively enhanced by the introduction of PDA,and that the amount of polymerization per unit volume was markedly increased.Then the prepared PPy polyurethane sponge material was applied to the sensing layer of the resistive ammonia sensor,and its gas-sensing properties were studied.It was observed that the device exhibited good humidity stability and could reliably operate in complex humidity environments.(2)A highly sensitive and portable sweat lactic acid sensor based on the PPy in situ modified carbon nanotube(CNT)was developed.The uniformly coated CNT-PPy nanocomposites were constructed by surface modification and low temperature polymerization.The effects of Py monomer concentration and polymerization time on the loading capacity of PPy and the resistivity of CNT-PPy nanocomposites were studied.The structure,composition and microstructure of CNT-PPy nanomaterials with different polymerization time and concentrations were fully characterized and analyzed.The effects of factors including temperature and PH on the lactic acid response current of CNT-PPy nanomaterials were investigated.The real-time monitoring and alarm system of lactic acid secretion during human movement were further designed.This innovation demonstrates the potential applications of this lactic acid sensor based on CNT-PPy composite nanomaterials in the context of health and safety protection.(3)Aiming at the problems of poor conductivity and stability of MOFs,PPy/CoMOF three-dimensional hierarchical porous material was prepared by a simple one-step hydrothermal method,and asymmetric supercapacitors were prepared using it as an electrode.The microstructure,structure and functional groups of the composites were characterized,and the electrochemical properties of the composites were analyzed in detail with the aid of electrochemical testing methods.The results show that the CoMOF/PPy electrode has a high specific capacity and good cyclic voltammetry properties.The asymmetric supercapacitor assembled based on this has a good energy density and power density,which offers a novel approach to the construction of high-performance supercapacitor pseudocapacitor electrode materials.更多还原