Electrospun Cobalt-Incorporated MOF-5 Microfibers as a Promising Electrocatalyst for OER in Alkaline Media

Abstract

Metal−organic framework (MOF)-based materials have attracted attention in recent times owing to their remarkable properties such as regulatable pore size, high specific surface area, and elasticity in their network topology, geometry, dimension, and chemical functionality. It is believed that the incorporation of a MOF network into a fibrous matrix results in the improvement of the electrocatalytic properties of the material. Herein, we have synthesized a Co-incorporated MOF-5-based fibrous material by a simple wet-chemical method, followed by an electrospinning (ES) process. The as-prepared Co-incorporated MOF-5 microfibers were employed as an electrocatalyst for the oxygen evolution reaction (OER) in 1 M KOH electrolyte. The catalyst demands a lower overpotential of 240 mV to attain a current density of 10 mA/cm 2 with a lower Tafel slope value of 120 mV/dec along with a charge transfer resistance value of 2.9 Ω from electron impedance spectroscopy (EIS) analysis. From these results, it has been understood that the incorporation of Co metal into the MOF-5 microfibrous network has significantly improved the OER performance, which made them a potential entrant in other energy-related applications also.

In Situ Electrochemical Activation of Fe/Co-Based 8-Hydroxyquinoline Nanostructures on Copper Foam for Oxygen Evolution

“…Figure b,c present the high-resolution XPS spectra for Co 2p and Fe 2p. The Co 2p spectrum of Co 0.1 Fe 0.4 -HQ/CF before OER shows two bands at 781.6 and 796.9 eV with two shake-up satellites at 786.0 and 802.6 eV, suggesting the presence of Co 2+ in the product . It is noted that the shift of the cobalt XPS bands with the oxidation state is quite different from those of other elements due to the so-called final state effect.…”

“…The Co 2p spectrum of Co 0.1 Fe 0.4 -HQ/ CF before OER shows two bands at 781.6 and 796.9 eV with two shake-up satellites at 786.0 and 802.6 eV, suggesting the presence of Co 2+ in the product. 50 It is noted that the shift of the cobalt XPS bands with the oxidation state is quite different from those of other elements due to the so-called final state effect. A red-shift of the XPS band occurs when the oxidation state is increased from Co(II) to Co(III).…”

Electrospun one-dimensional electrocatalysts for boosting electrocatalysis

“…53 Also, the 1D porous structure also enables accelerated electron mobility during electrochemical reactions, rendering electrospun 1D nanofibers promising electrocatalysts for energy conversion. 54 Finally, it is also reported that the electrospun nanomaterials can also work as a support for the uniform dispersion of active components. 55 Benefitting from these advantageous merits, these electrospun nanomaterials can thus work as promising electrocatalysts to largely promote the catalytic activity and efficiency.…”

Metallic Gold-Incorporated Ni(OH)2 for Enhanced Water Oxidation in an Alkaline Medium: A Simple Wet-Chemical Approach

“…This triggered the researchers to design less expensive, more potent, and robust catalysts by surface engineering with more active sites to improve their activity. Recently, extensive efforts have been made for developing third-row transition-metal-based catalysts such as oxides, , oxyhydroxide hydrates, hydroxides, , phosphides, sulfides, chalcogenides, , carbon composites, , and layered double hydroxides (LDH) for efficient OER in alkaline medium by many research groups ,− Especially, transition metals like Ni-, Fe-, and Co-based materials are used for effective OER application in alkaline medium. Among them, Ni is an earth-abundant first-row transition metal and its related nanocatalysts have a high impact toward the alkaline OER because of their good water oxidation activity, with lower overpotential and Tafel slope value.…”