球状纳米二氧化钛/石墨烯复合材料的合成及导电性能

采用改进的水热法制备二氧化钛/石墨烯(TiO2/G)复合导电材料,并研究水热温度以及石墨烯用量对TiO2/G复合材料导电性的影响。利用傅里叶变换红外(FTIR)光谱、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和电化学阻抗谱等测试手段对复合材料的结构,微观形貌以及导电性能进行表征,并确定最佳的水热温度以及石墨烯的最佳添加量。结果表明:石墨烯添加量为5%(质量分数),水热温度为160℃,TiO2/G复合材料的导电性最佳,其电阻率为13.46Ω·cm。复合材料中TiO2纳米颗粒为球状的锐钛矿相,直径为100~200nm左右,且均匀生长在石墨烯片层表面。其中,TiO2纳米颗粒生长于石墨烯片层上,有效地阻止石墨烯片层的聚集,有利于石墨烯片层间形成导电网络,提高电子迁移效率,赋予二氧化钛复合材料优异的导电性能。

Synthesis and electrical conductivity of spherical nano-TiO2/graphene composites

Titanium dioxide/graphene (TiO 2/G) composite conductive materials were prepared by modified hydrothermal method. The effects of hydrothermal temperature and the amount of graphene on the electrical conductivity of the composites were investigated. The structure, microstructure and conductivity of the composites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and so on, and the optimum hydrothermal temperature and the optimum doping amount of graphene were determined. The results show that the electrical conductivity of TiO 2/G is the best when the content of graphene is 5%(mass fraction), the hydrothermal temperature is 160℃, and its resistivity is 13.46Ω·cm. The nano TiO 2 in the composite is a spherical anatase phase with a diameter of about 100-200nm, and it is grown uniformly on the lamellar surface of graphene. Among them, the nano TiO 2 is grown on the graphene layers, which effectively prevents the agglomeration of the graphene layer, which is beneficial to the formation of conductive network between the graphene layers, improves the efficiency of electron migration, and endows the titanium dioxide composites with excellent electrical conductivity.