A Polycarboxyl‐Decorated Fe^III‐Based Xerogel‐Derived Multifunctional Composite (Fe₃O₄/Fe/C) as an Efficient Electrode Material towards Oxygen Reduction Reaction and Supercapacitor Application

Abstract

Low cost, non-noble metal catalysts with a good oxygen reduction reaction (ORR) activity comparable to that of platinum and also having good energy storage properties are highly desirable but challenging. Several challenges are associated with the development of such materials. Herein, we demonstrate a new polycarboxyl-functionalised Fe -based gel material, synthesised following a solvothermal method and the development of its composite (Fe O /Fe/C) by annealing at optimised temperature. The developed composite displayed excellent electrocatalytic activity for the oxygen reduction reaction with an onset potential of 0.87 V (vs. RHE) and a current density value of -5 mA cm , which are comparable with commercial 20 wt % Pt/C. In addition, as one of the most desirable properties, the composite exhibits a better methanol tolerance and greater durability than Pt/C. The same material was explored as an energy storage material for supercapacitors, which showed a specific capacitance of 245 F g at a current density of 1 A g . It is expected that this Fe O /Fe/C composite with a disordered graphitised carbon matrix will pave a horizon for developing energy conversion and energy storage devices.

Covalent Organic Framework Embedded with Magnetic Nanoparticles for MRI and Chemo-Thermotherapy

“…Deconvoluted N 1s spectra of the TAB-DFP-nCOFs indicate the presence of three distinct peaks at (i) 398.95 eV, corresponding to the imine nitrogen, (ii) 399.35 eV, associated with pyridinic nitrogen, and (iii) 399.95 eV, which is attributed to quaternary nitrogen (protonated pyridine on the surface) in the TAB-DFP-nCOF matrix (Figure S15e and Table S4). − Upon the addition of nanoparticles, there was a significant shift (0.5 eV) of the N -pyridine peak compared to the pristine nCOF (Figure S15f and Table S4), with all of the other peaks remaining unchanged. This shift toward low binding energies strongly indicates electron transfer from pyridinic nitrogen to the nanoparticles, as described by Pan et al, thus demonstrating that γ-Fe 2 O 3 NPs interact with the nCOF surface through N–Fe bonds. , …”

Metal–organic gels and their derived materials for electrochemical applications

“…The porous carbons PC600, PC800, and PC1000 have been demonstrated as efficient electrode materials with the respective specific capacitances of 213.1, 129.1, and 114.3 F g −1 . 191 When used for capacitive deionization, PC800 showed a notable desalination capacity of 25.16 mg g −1 at 1.4 V in 500 mg L −1 aqueous NaCl solution. It showed that MOG-derived porous carbons are potential electrode materials for high-performance water desalination.…”

“…Devi et al developed an Fe 3+ -based MOG of H 4 BTA that bears peripheral poly-carboxyl groups. 191 The FeBTA MOG was used to fabricate the Fe 3 O 4 /Fe/C composite via thermal treatment at 700 °C. The composite Fe 3 O 4 /Fe/C particles of ca.…”

Unlocking OER catalytic potential and chiral Fe3O4 film as a game-changer for electrochemical water oxidation pathway and by-product control

“…[46][47][48][49] These peaks are fitted using a shakeup satellite and two spin-orbit doublets, which originate from the Fe 3+ and Fe 2+ states. [46][47][48] The area ratio of Fe 3+ /Fe 2+ in the spectrum is approximately 2, indicating that the material deposited on the FTO substrate is Fe 3 O 4 .…”