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

Abstract

Titanium dioxide/graphene (TiO2/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 TiO2/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 TiO2 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 TiO2 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.

Keywords

• graphene
• titanium dioxide
• conductivity
• hydrothermal method
• composite conductive mat-erial