One-pot synthesis of graphene oxide sheets and graphene oxide quantum dots from graphite nanofibers

A one-pot synthesis of graphene oxide (GO) sheets and GO quantum dots using graphite nanofibers (GNF) as starting material is reported. Two types of GNF starting materials, namely herringbone and platelet structures, were used. HRTEM revealed that platelet GNF produces quantum dots typically less than 10 nm in size while herringbone GNF produces relatively larger GO sheets. SAED patterns indicate that the produced GO sheets have a hexagonal crystal structure. UV-Vis, PL, XPS, and Raman show salient differences between the produced GO nanostructures which correlate well with the morphological analysis. Unlike the GO sheets, the GO quantum dots are photoluminescent. The difference in PL properties was attributed to the higher oxygen content in GO quantum dots which were shown by XPS. The results offer a new insight to the importance of starting material in the synthesis of graphene nanostructures.