On the basis of the experimental results that we have analyzed and discussed above, the significant morphology difference between VG-S and VG-M is originated from their different reduction methods, and this morphology difference can be explained with the following hypothesis. VG-S is obtained from a conventional stirring method, where GO sheets are reduced by VC in a free environment. The rGO sheets are highly distorted in such a free environment due to the strong in-plane strain caused by the oxygen functionality removal, and thus form highly self-folded nanoparticles.