Adsorption of Methylene Blue onto Secondary Expanded Graphite

Abstract

A secondary oxidation and expansion of graphite process resulted in a specific surface area enhanced material, which could be used in methylene blue (MB) adsorption in industry, due to the low running cost and mass production. The morphology of the samples was investigated using scanning electron microscopy, and the structures vary from the expansion level. It was found that with a pH value about 9, the sample exhibited better adsorption property toward MB after re-expansion. The adsorption capability of MB adsorbed on unit mass of the secondary expanded graphite turned out to be 120mg/g. The considerable adsorption capability could be further enhanced through a multiple expansion process.