Terbium metal–organic frameworks as capable electrodes for supercapacitors
The porosity and activity of electroactive ions, such as rare earth ions in metal–organic frameworks (MOFs), offer those structures specific features, including abundant pores, high surface area and redox activity, which enables MOFs to be utilized as electrode material in supercapacitors. In this research, a terbium metal organic framework (Tb-MOF) [Tb2(fma)2(ox)(H2O)4·4H2O] (fma = fumarate and ox = oxalate) was synthesized using a hydrothermal process. The supercapacitive activity of Tb-MOF was examined by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements in 6 M KOH electrolyte. At a discharge current density of 1 A g−1 and with 91.9% capacitance retention after 4000 cycles, the Tb-MOF displays a specific capacitance (C) of 510 F g−1. As the results show, using electroactive lanthanides is a new horizon in MOFs as supercapacitor materials due to their outstanding characteristics and applications.