Enhanced high-temperature thermal conductivity of the reduced graphene oxide@SiO2 composites synthesised by liquid phase deposition

Abstract

Liquid phase deposition was developed to synthesise thermally conductive reduced graphene oxide@SiO2 (rGO@SiO2) composites for use in aerobic environments above 600 °C. This method is a mild, controllable reaction, good repeatability, easy operation, and low cost. The composition, morphology, oxidation resistance property, thermal conductivity (TC) property, and deposition dynamics of the rGO@SiO2 composites were systematically investigated in this study. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and high-resolution X-ray photoelectron spectroscopy (XPS) measurements proved that SiO2 particles were synthesised on the rGO. Spherical SiO2 particles were uniformly dispersed on both sides of the rGO, the SiO2 particle size was relatively uniform (∼500 nm), and there was no excessive aggregation. Isothermal oxidation and TC analyses showed that the rGO@SiO2 composite possessed better high-temperature and oxidation-resistance properties compared to pristine rGO, while still exhibiting excellent TC in the out-of-plane direction (k⊥) at 650 °C after 24 h. Moreover, the deposition dynamics of the rGO@SiO2 composite were established based on the analysis results. The synthesis method, liquid phase deposition, provides a promising route for the mild and controllable synthesis of rGO-ceramic composites for thermal management materials.