Ultrasound-assisted synthesis of rGO/SiO2-based nanosheets and their electrochemical performances in Li-ion batteries.

Abstract

In this study, a facile approach has been developed to fabricate GO/SiO2 nanosheets by the hydrolysis of tetraethyl orthosilicate (TEOS) in the graphene oxide (GO) solution with the assistance of the ultrasonication. The morphology and structure of the SiO2/GO nanosheets were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopy. The results showed that the covalently bonded SiO2 nanoparticles onto the GO sheets were dense and uniform. The agglomeration of the nanosheets was prevented by the ultrasonication and the layer sizes decreased throughout the synthesis process. The size and thickness of the SiO2 nanoparticles were determined by the initially and externally added TEOS amounts, respectively, on the GO surface. The anode performance of the thermally reduced rGO/SiO2 nanosheets was also observed in the Li-ion half-cell. The reversible capacity of the synthesized TrGOSN-1.5 anode was 424 mA h g-1 at a current density of 100 mA g-1.