“…Graphene has attracted considerable attention because of its fabulous mechanical, thermal, and electrical properties, and its promising application [2]. During these years, various methods have been used to prepare graphene, which can be approximately classified into bottom-up synthesis methods including chemical vapor deposition (CVD) [3,4], solution (solvent) method [5,6], and molecular beam epitaxy (MBE) [7,8], and top-down methods such as mechanical exfoliation (including the micromechanical cleavage method [1], ultrasonic method [9][10][11], and ball milling method [12], etc.) [1,[13][14][15][16], electrochemical method [17,18], oxidation-reduction method [19,20], and intercalation exfoliation method [21,22], etc.…”