Wrinkled Graphenes: A Study on the Effects of Synthesis Parameters on Exfoliation-Reduction of Graphite Oxide

In the present work, we have systematically investigated the effect of different exfoliation conditions on the synthesis of graphene from graphite oxide (GO). Four different conditions were used to exfoliate GO: Ar @ 1050 degrees C, vacuum @ 200 degrees C, H-2 + Ar mixture @ 200 degrees C, and H-2 @ 200 degrees C. Few layered graphenes obtained by these methods were characterized by thermogravimetry, diffractometry, spectroscopy, microscopy, surface, and elemental analysis techniques. New insights obtained upon a detailed analysis of these are presented. Although the morphology and characteristics of these graphenes are similar, differences are observed in the amount of functional groups present, resulting in considerable change in their electrical properties. These results show conclusively that the atmosphere for exfoliation of GO plays a critical role in low temperature syntheses of graphene. It is observed that exfoliation-reduction of GO in pure hydrogen atmosphere at 200 degrees C results in the highest quality of a few layered graphene sheets.