Fabrication of tricarboxylate-neodymium metal organic frameworks and its nanocomposite with graphene oxide by hydrothermal synthesis for a symmetric supercapacitor electrode material

Abstract

Efficient energy storage and delivery of electrical energy is necessary for the use of advanced electrode materials in super-capacitors, rendering their development pivotal. We employed simple and economical hydrothermal technique to synthesize Nd-metal organic frameworks (MOFs) and Nd-MOFs/GO composite and evaluated their suitability as electrode materials through comprehensive investigation. Characterizations of the synthesized materials were done by various techniques, including XRD, FTIR (using ATR method) and SEM. Based on the results obtained, it was found that the Nd-MOFs/GO composite-based electrode had a specific capacitance of 633.5 Fg−1 when tested at a current density of 0.3 Ag−1, which is significantly higher than that of Nd-MOFs electrode (11.3 Fg−1). Additionally, electrochemical impedance spectroscopy (EIS) analysis demonstrated the lowest equivalent series resistance (ESR) of 0.8 Ω for the Nd-MOFs/GO electrode. The Nd-MOFs/GO composite electrode exhibited a cyclic stability of 88.76 % after 4000 cycles and coulombic efficiency of 95.1%, when subjected to a current density of 3 Ag−1. Moreover XRD showed that the synthesized hybrid exhibited an improved crystallinity of the hexagonal phase. The FTIR analysis using ATR method confirmed the presence of organic ligands and functional groups in the synthesized materials. The results of our study indicate that the Nd-MOFs/GO hybrid nanocomposite-based electrode material holds potential as a highly efficient candidate for super-capacitor applications. The reported method of synthesizing MOFs provides an effective approach to fabricate new electrode materials with excellent electrochemical characteristics.