Improving the surface area of metal organic framework-derived porous carbon through constructing inner support by compatible graphene quantum dots

Abstract

Metal-organic frameworks (MOFs) have emerged as promising precursors to prepare porous carbons due to their unique coordination structure with abundant pores and various chemical compositions. However, the structural collapse and pore shrinkage during pyrolysis severely decrease the surface area of the prepared porous carbons. Herein, we propose an inner support strategy to prepare MOF-derived carbons with improved surface area using graphene quantum dots (GQDs) as the compatible frameworks. GQDs with abundant carboxyl groups (–COOH) and rigid structure can uniformly distribute in MOF-5 precursor by coordinating with [Zn4O]6+ clusters and effectively reinforce the carbon skeleton during pyrolysis. Therefore, the rational GQDs embedded MOF-5 derived porous carbon (GMPC-0.35) shows greatly improved specific surface area (1841 m2 g−1) and mesopore volume (1.62 cm3 g−1) than pure MOF-5 derived carbon (1358 m2 g−1, 0.59 cm3 g−1). As an application exemplification, GMPC-0.35 performs high specific capacitance of 200 F g−1 at 1 A g−1 and good capacitance retention of 53% at 100 A g−1 as the electrode material for supercapacitors, which are higher than most of the reported MOF-5 derived carbons. Therefore, the compatible GQDs support is promising for preparing functional MOF-derived carbon materials.