Green Extraction of Graphene from Natural Mineral Shungite

ABSTRACT:

Conventional fabrication methods to produce graphene are cumbersome, expensive, and not ecologically friendly. This is because processing a large volume of raw materials requires large amounts of acids and alkalis, which, in turn, require particular disposal. Therefore, developing new technologies or refining existing ones is necessary to produce graphene—and to create new, ecologically safe and effective methods. Here, we utilized physical sonication to extract graphene films from natural mineral shungite rock. From our study of the structure of shungite by Raman spectrometry and X-ray phase analysis, we found that shungite is characterized by graphite-like mineral structures. Transmission electron microscopy images obtained from the processed material revealed graphene films—with surfaces as small as 200 nanometers long and several layers wide. Our green method of fabricating graphene can be widely used in various fields, from electro-optics to ecology, to list a few.