Does silicate mineral impurities in natural graphite affect the characteristics of synthesized graphene?

The effects of silicate minerals in starting natural graphite on the preparation and characteristics of reduced graphene oxides (rGOs) have been studied in this work. The study was performed through the measurements of ICP, XRD, FTIR, Raman spectra, UV spectra, AFM and electrochemical performance. The experimental results had shown that the characteristics of the synthesized rGOs, such as layer thickness, defect degree and specific capacitance, etc., were not correlated with silicate minerals assaying in the starting graphite, and no silicate impurities were involved into the rGOs. The mechanism might be attributed to that the silicate minerals were removed from the graphene oxide (GO) in the graphene preparation. This finding suggested that it was not necessary to eliminate deeply silicate minerals from natural graphite before it was used as the starting graphite for the synthesis of graphene with the chemical reduction method, leading to less environmental concerns and lower operation costs. (C) 2015 Elsevier Ltd. All rights reserved.