Graphene induced formation of single crystal Pt nanosheets through 2-dimensional aggregation and sintering of nanoparticles in molten salt medium

Shape controlled synthesis of Pt nanoparticles is of great significance for the development of electrochemical catalysts with high performance. In this study, we found that the reduced graphene oxide can induce the growth of 2-dimentional single crystal Pt nanosheets with a thickness of about 9.8 nm in a KNO3–LiNO3 eutectic mixture molten salt medium without using any organic solvent, capping agents or structure-directing agents. A series of investigations to understand the formation mechanism indicated that the aggregation and sintering of the isolated nanoparticles along the surface of reduced graphene oxide was responsible for the formation Pt nanosheets. The electrochemical tests indicated that the as-prepared hybrid material exhibited an enhanced activity and durability toward the methanol oxidation compared with the commercial used Pt/C catalysts.