Metal–organic framework-driven copper/carbon polyhedron: synthesis, characterization and the role of copper in electrochemistry properties

A facile synthetic strategy has been developed to harvest copper/carbon polyhedron (Cu/C-X, X = 1, 2, 3) with varisized Cu nanoparticles contained in porous carbon matrix from the pre-fabricated Cu-BTC (BTC = benzenetricarboxylic acid), of which Cu/C-1 has good structural integrity and smaller embedded Cu nanoparticles. The Cu/C-3 is acid treated from Cu/C-1 which possesses integrated structure and numerous newborn pores by removal of in situ Cu nanoparticles. Benefited from integrated morphology and newborn porous structure, the Cu/C-3 exhibits enhanced electrochemical double-layer capacitance (C_dl, 19.4 mF cm⁻²), which is 2.7- and 12.9-fold as large as that of Cu/C-1 and Cu/C-2, respectively. Further, electrochemical measurements indicate that the electrochemical properties of Cu/C samples highly depend on porosity, structural integrity and the distribution of Cu nanoparticles. In addition, it is found that proper distribution and size of Cu nanoparticles embedded into carbon matrix are beneficial to faster electron transport and mass transfer. This work presents a facile synthesis method of novel Cu/C polyhedron with homogeneous distributed Cu nanoparticles, which could be further investigated in the application of high-performance electrode for supercapacitors.