Electrochemical properties of MOF-derived nickel compounds for high performance supercapacitor and electrocatalysts

There are many different ways that energy is used in daily life. From applications that require a high energy density to long-term storage in a stable manner, the requirements for energy usage are diverse. Therefore, the greater the number of uses a designed material exhibit, the more practical it may be for wide-scale manufacture. An emerging class of functional porous materials referred to as metal-organic framework (MOF) has received considerable attention over the past two decades, partially because of their potential use in a wide variety of applications, including gas storage, molecular separations, water splitting, and supercapacitor devices. In addition, an electrode material with high performance as an essential part is highly desirable for supercapacitors. Herein, we synthesize the nickel-MOF (Ni-MIL-77) via an in-situ synthesis route using glutaric acid in a hydrothermal process at different temperatures @ 140, 160, and 180 °C. As an electrocatalyst for hydrogen evolution reaction (HER), Ni-MIL-77@140 displayed the lowest overpotential of 126 mV. On the other hand, Ni-MIL-77@160 showed the lowest overpotential of 330 mV among all samples for oxygen evolution reactions (OER). In terms of energy storage, the Ni-MIL-77@160 had the highest specific capacitance of 603 F/g at a current density of 1 A/g with an energy density of 25 W-h/kg and power density of 272 W/kg. This works offers the facile way to rationally design and synthesize the MOF-based electrodes for powerful and stable supercapacitor and also the efficient way for water splitting