Simple and cost-effective reduction of graphite oxide by sulfuric acid

We report a simple, cost-effective, and environmentally benign process for reducing graphite oxide by treating solely with sulfuric acid. The suggested process consists of a two-step reduction of graphite oxide, first in aqueous sulfuric acid at room temperature and then in concentrated sulfuric acid with refluxing. X-ray diffractometry, X-ray photoelectron spectroscopy, Raman spectroscopy and thermogravimetric analysis demonstrated that the graphite oxide was reduced effectively and was comparable in composition to reduced graphite oxide prepared using previously described methods that rely on toxic and hazardous reducing agents, such as hydrazine, sodium borohydride, or hydrohalic acids. (C) 2011 Elsevier Ltd. All rights reserved.