Silicon-graphene composite synthesis: Microstructural, spectroscopic and electrical conductivity characterizations

Abstract

In this research work, we explored an idea to successfully prepare Si-graphene (0.5–1.5 wt%) composites by an uniquely in-house designed planetary ball milling process. XRD of Si-graphene composites show major peak of Si (1 1 1) and C(0 0 2). With increasing addition of graphene, intensity of C(0 0 2) peak is found to be increased in the composites. Raman spectra show peaks of Si along with different peaks of carbon such as D, G and 2D peaks. Micro Raman and TEM characterizations indicate that graphene in the Si-graphene (1–1.5 wt%) composite is developed in bi-layer form. HRTEM of typical Si-graphene (1 wt%) composite confirms the formation of composite between graphene and silicon. XPS spectra of de-convoluted high resolution C 1s and Si 2p further confirm the formation of Si-graphene composites. XPS spectra of composites show that more amount of Si is converted into composite with graphene along with also presence of only free Si. When graphene (0.5–1.5 wt%) is added to Si, it is observed that the specific surface area is improved significantly from 87 to 304 m2 g−1. In this work, it is found that the typical Si-graphene (1 wt%) composite exhibits 11% more electrical conductivity than pure Si.