Preparation Of Poly(3,4-ethylenedioxythiophene)/inorganic Hybrid Composite And Study Of Its Thermoelectric Properties

In recent years,energy shortages and environmental protection problems have become increasingly serious,and the development and application of' green energy-saving energy materials is imminent.As a special functional material that can realize the mutual conversion between thermal energy and electrical energy,thermoelectric materials are receiving more and more attention from researchers.The research and development of traditional inorganic thermoelectric materials have made great progress.However,inorganic thermoelectric materials also face many problems,such as limited resources,high price,poor processability and certain toxicity,which limits their large-scale application.Conductive polymers are rich in resources,light in weight,easy to process,good in environmental stability and low in thermal conductivity,and have gradually become the research focus in the field of thermoelectrics.Poly(3,4-ethylenedioxythiophene)(PEDOT)is one of the most valuable polymers in the field of thermoelectrics due to its high electrical conductivity,low thermal conductivity,easy processability and good environmental stability.However,pure PEDOT is insoluble in water and other solvents,and usually needs to be doped with polystyrenesulfonic acid(PSS)to form a water-soluble poly(3,4 ethylenedioxythiophene):polystyrenesulfonic acid(PEDOT:PSS).However,the PSS in PEDOT:PSS is an insulating material,which greatly affects its electrical conductivity,resulting in its relatively low thermoelectric figure of merit,which is not conducive to its application in the field of thermoelectricity.And commercial PEDOT:PSS is expensive and the solution is acidic,and further environmental problems cannot be ignored.Therefore,it is of great practical significance for PEDOT to further improve its thermoelectric properties on the basis of good water solubility and dispersibility.Studies have shown that the preparation of organic/inorganic composite thermoelectric materials can effectively combine the advantages of both,and use synergistic effects to improve the thermoelectric properties of materials.Therefore,PEDOT nanowires(PEDOT NWs)with good water solubility and dispersibility and excellent thermoelectric properties were synthesized,and PEDOT NWs/inorganic composite thermoelectric composites were prepared.The thermoelectric properties were tested and analyzed.PEDOT NWs were successfully prepared by the micelle soft template method.The prepared PEDOT NWs had good dispersibility and high electrical conductivity(249.5 S cm-1).The PEDOT NWs/Bi2Te3 composite films were prepared by vacuum filtration.The addition of Bi2Te3 was particularly effective in improving the electrical conductivity of the composite films,and the electrical conductivity was up to 727.29 S cm-1.Then,Bi2Te3 nanowires(Bi2Te3 NWs)were successfully prepared by wet chemical method,and PEDOT NWs/Bi2Te3 NWs composite films were prepared as inorganic components,which solved the problem of dispersion of Bi2Te3 in PEDOT NWs matrix.The electrical conductivity and Seebeck coefficient of the composite films are improved compared to the Bi2Te3 powders series composite films,and the power factor is 9.06 ?W m-1 K-2.In addition,from the perspective of improving the Seebeck coefficient(S)and improving the thermoelectric properties of the material,Te nanowires(Te NWs)with large Seebeck coefficient were synthesized,and PEDOT NWs/Te NWs composite films were prepared.The power factor of the composite material was significantly increased to 58.03?W m-1 K-2.XRD,SEM,TEM and other characterization techniques were used to analyze the effects of the structure and morphology of each composite material on its thermoelectric properties.Finally,a flexible thermoelectric power generation device was fabricated using PEDOT NWs/Te NWs composite film as raw material.This thermoelectric device can generate an output voltage of 2.8 mV using the temperature difference between the human body and the environment.