文摘
An ordered porous Mn3O4@N-doped carbon/graphene (MCG) composite has been synthesized through a facile carbonization of Mn-based metal–organic frameworks (Mn-MOFs) using the poly(styrene-co-AA) spheres as the template. Because of the periodic arrangement of metal nodes and organic ligands in the Mn-MOFs, the Mn3O4 nanoparticles with an average diameter of 7 nm are uniformly distributed and the carbon is formed in situ in the MCG composite. The MCG exhibits a specific surface area of 326 m2 g−1 with a total pore volume of 1.02 cm3 g−1, which is much higher than that of the Mn3O4-based composites reported to date. In addition, the MCG displays excellent electrochemical performances in an aqueous 1 M Na2SO4 electrolyte with a maximum specific capacitance of 456 F g−1 at 1 A g−1 and 246 F g−1 at 20 A g−1. The MCG also owns a good cycling stability with 98.1 % of the initial capacitance remaining after 2000 cycles at 5 A g−1.