Affiliation:
1. School of Chemical Sciences Indian Institute of Technology Mandi Kamand Himachal Pradesh 175075 India
2. School of Mechanical and Materials Engineering Indian Institute of Technology Mandi Kamand Himachal Pradesh 175075 India
Abstract
AbstractThe development of an efficient and cost‐effective material is highly desirable for electrochemical devices such as electrolyzers and supercapacitors. Especially, pseudomorphic transformations of metal‐organic frameworks (MOFs)/coordination polymers (CPs) into layered double hydroxides (LDHs) materials endow well‐defined porosities, high surface area, exchangeable interlayer anions and easily adjustable electronic structure that are truly required for oxygen evolution reaction (OER) and high‐performance supercapacitor applications. Herein, we have prepared NiFe‐LDHs of various Ni/Fe ratios via a facile room‐temperature alkaline hydrolysis of NiFe‐CPs precursors. Electrochemical studies reveal that the catalyst having high amount of Fe (Ni1.2Fe1‐LDH) showed the better OER activity with a low Tafel slope (65 mV dec−1) in 1 M KOH. On the other hand, the catalyst containing higher amount of Ni with better layered structure (Ni11.7Fe1‐LDH) showed high performance for supercapacitor (702 F g−1 at 0.25 A g−1) in 3 M KOH. Moreover, a solid‐state asymmetric supercapacitor device Ni11.7Fe1‐LDH/AC was fabricated which exhibited a specific capacitance of 18 F g−1 at a current density of 1 A g−1. The device displayed high cycling stability with 88% of capacitance retention after 7000 cycles. The experimental findings in this work will help in the futuristic development of NiFe‐LDH based electrocatalysts for the enhanced electrochemical performances.