Synthesis of vanadium metal-organic framework, characterization, and study of electrochemical properties for using in supercapacitor and oxygen evolution reaction

Abstract

Transition-metal (V) based metal–organic framework drew a lot of attention for use in upcoming generation electrochemical energy storage devices (Supercapacitors) and energy production during oxygen evolution reaction (OER). The large surface area, the exposed metal sites, and structural controllability make MOFs preferred heterogeneous catalysts for various catalytic reactions. Due to their tunable structures and high porosity, MOFs have shown favorable applications as electrode materials for supercapacitors. This investigation synthesized V-MOF nanorods by hydrothermal and microwave methods. The NiCo2S4/V-MOF@rGO synthesized offered a maximum specific capacitance of 1844F/g at a current density of 1.0 Ag−1. Moreover, an asymmetric supercapacitor NiCo2S4/V-MOF@rGO//AC exhibits a high energy density of 800 Wh kg−1 at a power density of 61.10 W kg−1 and 98 % of its capacitance retention after 3000 cycles. In another part of this study, the V-MOF synthesized in the previous step showed an excellent electrocatalytic performance toward the OER. Furthermore, by compositing it with graphene sheets and doping it with phosphorus as a heteroatom, its electrocatalytic activity toward OER was further enhanced, showing160 mV overpotential at a current density of 10 mA cm−2 in a 3.0 M KOH after 1000 sweeps aqueous solution. This researches present a simple, efficient, and high-performance electrocatalyst for OER and active material for supercapacitors.