Capacitance Enhancement of Metal–Organic Framework (MOF) Materials by Their Morphology and Structural Formation

Abstract

Three types of metal−organic framework (MOF) materials were designed, synthesized, characterized, and thoroughly evaluated for their specific capacitance. Imidazole, adenine, and a mixture of both compounds along with nickel were used to synthesize the three MOFs (Imz-MOF, Imz + Adn-MOF, and Adn-MOF). The synthesized materials were subjected to standard characterization techniques. The surface morphology of the materials was studied using field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and atomic force microscopy (AFM) analyses. The Imz-MOF possesses a cubic structure, while Imz + Adn-MOF and Adn-MOF show a flake and mixed flake-like structures. The effect of the morphology and molecular structural formation was studied and explained systematically. The Brunauer−Emmett−Teller (BET) analysis was used to study the surface area and porous nature of the materials. The capacitance of the materials was evaluated using an electrochemical workstation with 3 M KOH as an electrolyte at various sweep rates and a galvanostatic charge−discharge (GCD) test at different current densities. The results show that the maximum efficiencies of Imz-MOF, Imz + Adn-MOF, and Adn-MOF were obtained at 407.42, 80, and 60 F g −1 values, respectively. The materials demonstrated good recycling properties even after 5000 cycles. The higher capacitance of Imz-MOF could be attributed to the structural formation and the ligand-to-metal electron donation, which enhances the conductivity of the material. The imidazole group contributes to the material's conductivity and charge-transfer (CT) nature. Based on the capacitance performance results of the materials, it is confirmed that Imz-MOF possesses a superior efficiency over Imz + Adn-MOF and Adn-MOF.

Triethanolamine assisted synthesis of bimetallic nickel cobalt nitride/nitrogen-doped carbon hollow nanoflowers for supercapacitor

“…The lattice ring is assigned to the (101) and ( 111 To investigate the pore nature of the precursors and Ni 3 N-Co 2 N 0.67 /NC, N 2 adsorption-desorption measurement was conducted, as shown in Supplementary Figure 3A-D and Figure 3A. All the isotherms belong to type IV, indicating their mesoporous characteristics [32] . The specific surface areas of N 0 C 3 -TEOA, N 1 C 2 -TEOA, N 1 C 1 -TEOA, N 2 C 1 -TEOA and N 3 C 0 -TEOA are found to be 18.88 m 2 g -1 , 20.98 m 2 g -1 , 18.35 m 2 g -1 , 1.573 m 2 g -1 and 0.844 m 2 g -1 , respectively.…”

A Review on Metal–Organic Framework as a Promising Catalyst for Biodiesel Production

“…66,65 By carefully selecting the metal ion core 67 and ligand group, 68 MOFs may be theoretically customized in characteristics like pore size as well as bonding strength. 69 Ligands containing side chains can be employed to extend the material's functionality, providing the prospect of a genuinely adjustable system at the molecular level. 70,71 Figure 2b depicts the techniques/methodologies used for the MOF's synthesis.…”

“…Metal ions can be categorized as soft acid-based metal ions or hard metal ions when combined with organic ligands which include useful carboxylate moiety functions like more diligent bases, or more delicate bases, as well as the azolate ligands. Aside from soft linkers, hard O-donor linkers with low p K a are inclined to connect with high-valent metallic ions with higher charge density to give superior chemical steadiness. , By carefully selecting the metal ion core and ligand group, MOFs may be theoretically customized in characteristics like pore size as well as bonding strength . Ligands containing side chains can be employed to extend the material’s functionality, providing the prospect of a genuinely adjustable system at the molecular level. , Figure b depicts the techniques/methodologies used for the MOF’s synthesis …”

Supercapacitive study for electrode materials around the framework-collapse point of a Ni-based coordination polymer

“…, have been obtained, and researchers are still dedicated to improving CP-based electrode materials through novel chemical and physical methodologies. 5–7 However, the disadvantages of poor electrical conductivity and unstable structure of CPs still limit their commercial application.…”

“…By replacing different organic ligands or transition metals with conjugated systems, various CPs, such as Ni-MOF, Fe-MOF, Co/Zn-MOF, etc., have been obtained, and researchers are still dedicated to improving CP-based electrode materials through novel chemical and physical methodologies. [5][6][7] However, the disadvantages of poor electrical conductivity and unstable structure of CPs still limit their commercial application.…”