One-step room-temperature preparation of expanded graphite

Here, we propose a simple, effective method to prepare expanded graphite in which the intercalation and expansion of graphite are realized by only one step under ambient conditions, not involving any heating or any sophisticated devices. We demonstrate that the expanded graphite prepared by such an one-step room-temperature method exhibits an expansion volume of up to 225 times. Most importantly, the used amount of concentrated H2SO4, which acts as the intercalant, can be dramatically decreased by about 85% in comparison to that used in the conventional methods, which will greatly reduces the effluent and alleviate the environmentally detrimental effect caused by the excessive usage of H2SO4.