Synthesis of UV-11 MOF and Its Characterization by Cyclic Voltammetry

Abstract

In this work a Metal-Organic Framework (MOF) was prepared using a solvothermal method, taking as precursors 1. 2-di-(4-pyridyl)-ethylene, 1.2.4.5-benzenetetracarboxylic acid and Co(No₃)₂-6H₂O. This MOF was called UV-11 and was evaluated using microscopic, spectroscopic and electrochemical techniques. According to the obtained results, the melting point of the compound is located in a higher interval than its precursors. Stereoscopic microscopy analysis shows the presence of pink crystals in the form of needles. MEB technique displays a laminar morphology as well as crystals with approximate sizes (36 mm wide and 150 mm long). EDS analysis corroborated the presence of precursor elements such as cobalt, carbon and oxygen. Furthermore, the XRD technique shows the cobalt-related phases in the sample, which is cobalt bis (pyridine-6-carboxylic-2-carboxylate). A modified carbon paste electrode was prepared using MOF UV-11 and by cyclic voltammetry electrochemical technique, semi-reversible redox processes are identified, as well as thermodynamic and kinetic parameters were obtained with the Laviron equation, and electrochemical performance properties from the cyclic voltammetry experimental data.

Keywords: MOF (Metal–Organic Framework); characterization-analysis; electroanalysis; electrochemistry (cyclic voltametry); interface mechanical behavior; micro supercapacitor.

Figure 1

MOF UV-11 unit cell simulation.

Figure 2

Stereoscopic microscopy of MOF.

Figure 3

MOF micrograph (a) and dispersed electron spectrum (b).

Figure 4

MOF theoretical diffraction comparison (A) experimental and (B) theoretical.

Figure 5

Cyclic voltammetry comparison of MCPE electrode (solid line) and CPE (discontinued line) at a scan rate of 25 mVs⁻¹.

Figure 6

Cyclic voltammetry of MCPE with different positive inversion potentials (E_λ+) in an electroactive range of 350–1200 mV, evaluating every 50 mV, at a scan rate of 25 mVs⁻¹.

Figure 7

MCPE cyclic voltammetry at different scanning rates vs. SCE 100 mVs⁻¹ (–), 50 mVs⁻¹ (- - -) and 25 mVs⁻¹ (···). The insert shows the current dependency to the logarithm of scan rate.

Figure 8

The electrochemical performance of the MCPE using voltammetry data, (A) response of the specific areal Capacitance vs. Scan rate and (B) the Ragone plot of the electrochemical performance.

Figure 9

The electrochemical performance of the MCPE using voltammetry data, (A) response of the specific areal Capacitance vs. Scan rate and (B) the Ragone plot of the electrochemical performance.