Facile Surface Properties Engineering of High-Quality Graphene: Toward Advanced Ni-MOF Heterostructures for High-Performance Supercapacitor Electrode

Metal–organic frameworks (MOFs) have emerged as one class of the most promising electrode materials for supercapacitors because of their high surface area and tunable pore structures. The development of MOF heterostructures based on high-quality graphene (HQG) which aims at superior capacitive properties while overcoming poor solution processability and reactivity of HQG is of great concern. In this work, a heterolayered MOF composite was prepared by a facile glucose modification of HQG and controlled nucleation and growth of lamellar Ni-MOF on the HQG surface. The introduction of oxygen-containing functionalities in our approach not only improves the interfacial interactions to form two-dimensional heterostructures but also enhanced the synergistic effects between Ni-MOF and HQG substrates. The constructed GM-LEG@Ni-MOF exhibits excellent capacitance of 987.6 F g–1 at the current density of 0.5 A g–1 and a high capacity retention (85.6%) after 3000 cycles, owing to its favorable electrochemical kinetics and highly structural stability.