NiFe Layered Double Hydroxide Electrocatalysts for an Efficient Oxygen Evolution Reaction

Abstract

Alkaline electrolysis is one of the most promising among gas-to-power technologies to produce hydrogen energy where the oxygen evolution reaction (OER) plays an important role. It has recently been demonstrated that the OER activity of layered double hydroxide (LDH) could be enhanced by accommodating more abundant active sites that offer optimal binding energies between intermediates. Here, we report a study of nickel iron layered double hydroxides by varying the Ni:Fe atomic ratio of the Ni 1−x Fe x -LDH to induce changes to their physiochemical properties through which the optimum OER performance is determined. Optimized NiFe-LDH-38 (Ni 0.62 Fe 0.38 LDH) shows an excellent OER performance in alkaline electrolyte, demonstrating a potential of 1.45 V (vs RHE) at 100 mA cm −2 , which outperforms the commercial RuO 2 catalyst. Also, computational simulations support the OER performance of the single NiFe-LDH phase . This work provides not only a fundamental understanding of the effect of the Ni:Fe atomic ratio of the Ni 1−x Fe x -LDHs on OER performance but also the design strategy of lowcost, earth abundant, and active electrocatalysts toward water oxidation.

NiFe-LDH/MXene nano-array hybrid architecture for exceptional capacitive lithium storage

“…49 It was noted that the presence of an Fe 3+ /Ni 2+ –O–Ni 2+ band at 423.7 cm −1 also confirmed the successful synthesis of NiFe-LDH. 42 In addition, compared with MXene, the peaks at 152.68 and 411.36 cm −1 of NiFe-LDH/MXene-500 revealed a slight blue-shift, which also manifested the successful preparation of the LDH/MXene hybrid material.…”

“…The peaks at binding energies of 726.7 and 714.1 eV indicated Fe 3+ 2p 1/2 and 2p 3/2 , while the peaks for Fe 2+ 2p 1/2 and 2p 3/2 were at 723.5 and 711.2 eV. 42,43 Fig. S2d † presents the Ti 2p spectrum, where two main peaks describing Ti 2p 1/2 and Ti 2p 3/2 orbitals could be observed.…”

Mesoporous Strontium Hydroxide Hydrate as a Nanostructure-Dependent Electrocatalyst for Hydrogen Evolution Reaction

“…19−21 Moreover, the existence of the Bronsted ligands, OH −1 , can enhance the adsorption and desorption of the active hydrogen atoms at the active sites of strontium, ultimately increasing the electrocatalytic behavior for water splitting. 17,22,23 Furthermore, the morphology at the nanoscale of the electrocatalysts has remarkable impacts on the HER. Morphology can control the specific surface area, porosity, intrinsic electronic states, and surface chemistry of the electrocatalysts for the HER process.…”

“…Hydroxides reveal the covalent bonds between hydrogen and oxygen, and their acidic conjugate is water. Owing to resistance against corrosion, earth abundance, cost-effectiveness, and good electrocatalytic performance, hydroxides have been found to be effective for electrocatalytic behaviors. − Furthermore, the metal oxide- and hydroxide-based catalysts also exhibit the intrinsic catalytic features in various catalysis phenomena, i.e. , photocorrosion due to the passivation of surface states .…”

“…Strontium is an alkaline metal and is usually found with Sr +2 oxidation states. Strontium-based compounds reveal good electrical conductivity and thermal and chemical stability, which make their remarkable applications in various fields. − Moreover, the existence of the Bronsted ligands, OH –1 , can enhance the adsorption and desorption of the active hydrogen atoms at the active sites of strontium, ultimately increasing the electrocatalytic behavior for water splitting. ,, …”