“…Since the discovery of graphene in 2004 [6], it has been used in diverse fields, such as electronics [7], batteries [8,9], biological sensors [10] and supercapacitors [11,12], etc. In recent years, graphene has been prepared by a variety of methods, for instance, mechanical exfoliation [6], chemical vapor deposition [13], epitaxial growth [14] and chemical reduction of graphite oxide (GO) [15,16], etc. Thereinto, chemical reduction has drawn special attention on account of its simplicity, reliability and well-controlled reduction degree [17,18].…”