Highly Active and Easily Fabricated NiCo₂O₄ Nanoflowers for Enhanced Methanol Oxidation

Abstract

Metal oxides with tailored nanomorphology represent a powerful tool to improve the electrocatalytic activity. Herein NiCo2O4 nanoflowers were synthesized via facile microwave method. NiCo2O4 nanoflowers were characterized by scanning and transmission electron microscopy, X‐ray diffraction (XRD), Raman spectroscopy, N2 gas adsorption/desorption, and X‐ray photoelectron spectroscopy (XPS). Through comparing NiCo2O4 nanoparticle vs nanoflowers morphology, NiCo2O4 nanoflowers have a superior mass and specific electroactivity towards oxygen evolution reaction (OER) by achieving a current density of 10 mA/cm2 at an overpotential of only 280 mV in 1M KOH electrolyte. Moreover, NiCo2O4 nanoflowers display superior performance for methanol electrooxidation in fuel cells by achieving 200 A/g and recovers 92.3 % of the original activity through the addition of new (1M KOH + 0.5M methanol) electrolyte after 500 cycles.

Rationally stabilized hierarchical NiCo2O4 hollow nanoballs for high-performance asymmetric supercapacitors and excellent methanol oxidation

“…However, as various reports in the literature used 1 M KOH as the electrolyte to study the methanol oxidation applicability of materials, it has been utilized for comparative analysis. 70–72 Fig. 7a shows that with the addition of MeOH in the host electrolyte the anodic current was increased and kept increasing until 0.5 M MeOH concentration, after which a dip was observed.…”

Recent advances in nanoflowers: compositional and structural diversification for potential applications

“…104 To the best of our knowledge, microwave reactions are utilized for producing various nanoflowers based on Ni through the interaction of molecules, which is facilitated by localized indirect heating within the solution. 73,105,106…”

Spinel Nickel–Cobalt Oxide Nanorods Supported on Ti3C2Tx-MXene Nanosheets as Electrocatalysts for the Methanol Oxidation Reaction via a CO-Free Pathway

“…6−8 Spinel nickel cobaltite (NiCo 2 O 4 ) electrocatalysts are suitable for ADMFCs because NiCo 2 O 4 improves the methanol electrooxidation activity by facilitating fast electron transfer from the substituted Ni 2+ to Co 2+ in the spinel lattice, and they have a lower affinity for CO poisoning than other metal catalysts. 9,10 To improve the electrocatalytic performance, adequate morphological control of the NiCo 2 O 4 nanostructure is an efficient tactic that can significantly improve their atom utilization, electroactivity, and long durability. 11−14 Because of their distinctive physical and chemical characteristics, one-dimensional (1D) NiCo 2 O 4 nanorods have received considerable interest in electrocatalysis.…”

“…Numerous publications have reported on transition metal oxide electrocatalysts as non-noble metal catalysts to improve the performance of the alcohol oxidation reaction due to the advantage of high redox reactions and improved electron conductivity. − Spinel nickel cobaltite (NiCo 2 O 4 ) electrocatalysts are suitable for ADMFCs because NiCo 2 O 4 improves the methanol electrooxidation activity by facilitating fast electron transfer from the substituted Ni 2+ to Co 2+ in the spinel lattice, and they have a lower affinity for CO poisoning than other metal catalysts. , To improve the electrocatalytic performance, adequate morphological control of the NiCo 2 O 4 nanostructure is an efficient tactic that can significantly improve their atom utilization, electroactivity, and long durability. − Because of their distinctive physical and chemical characteristics, one-dimensional (1D) NiCo 2 O 4 nanorods have received considerable interest in electrocatalysis. The specific 1D morphology makes NiCo 2 O 4 nanorods effective. , As a result, the NiCo 2 O 4 nanorods exhibit superior activity for electrocatalytic reactions in contrast to other traditional nanostructures such as urchin, coral, sheaf, quasi-spherical, and hexagonal plates …”