苯胺四聚体/还原氧化石墨烯薄膜的热电性能研究

Thermoelectric Properties of Aniline Tetramer/Reduced Graphene Oxide Films

为了增强石墨烯的热电性能,在氧化石墨烯(GO)中掺入不同量的苯胺四聚体(ANIT),采用酸性碘化钾溶液在100℃加热1 h将其还原为还原氧化石墨烯(rGO)薄膜。研究了含不同苯胺四聚体掺杂量的复合薄膜的组成、微结构与热电性能之间的关系。结果表明:ANIT掺杂在rGO的表面与片层之间增强了其导电连接,随着ANIT掺杂量的增大,ANIT/rGO复合薄膜载流子浓度基本保持不变,当ANIT与GO质量比小于2.5∶100时,载流子迁移率随掺量的增加而升高;然而大量的ANIT掺杂却增大了石墨烯片层间距,当ANIT与GO质量比大于2.5∶100时,载流子迁移率随掺量的增加而下降。当ANIT/rGO复合薄膜的塞贝克系数基本不变时,电导率和功率因数随着载流子迁移率的变化而变化,在ANIT和GO质量比为2.5∶100时,电导率和功率因数均达到最大值,分别为212 S/cm和6.4μW/(m·K^(2))。

To improve the thermoelectric properties of graphene,different content of aniline tetramer(ANIT)was incorporated into graphene oxide(GO)to form ANIT/GO films.An acidic potassium iodide solution was used as a reducing agent to reduce ANIT/GO films at 100℃for 1 h and the ANIT/reduced graphene oxide(rGO)films were obtained.The relationships of composition,microstructure and thermoelectric properties of the composite films with different amounts of ANIT were investigated.The results show that the ANIT doping enhances the conductive connection between the surface and the layers of rGO,and the carrier concentration of ANIT/rGO composite films remains basically unchanged with the increase of ANIT content,when the mass ratios of ANIT to GO are lower than 2.5∶100,the carrier mobility of the composite films increases with the increase of ANIT content.However,excessive incorporation of ANIT enlarges the spacing of graphene layers,causing a reduction of the conductivity,and when the mass ratios of ANIT to GO is higher than 2.5∶100,the carrier mobility of composite films decreases with the increase of ANIT content.When the Seebeck coefficients of ANIT/rGO composite films are basically unchanged,the conductivity and power factor change with the change of carrier mobility.The maximum values of electrical conductivity and power factor are 212 S/cm and 6.4μW/(m·K^(2)),respectively,when the mass ratio of ANIT and GO is 2.5∶100.