Influence of Fe-clustering on the water oxidation performance of two-dimensional layered double hydroxides

Abstract

Among the two-dimensional (2D) materials family, layered double hydroxides (LDHs) represent a key member due to their unparalleled chemical versatility. Specially, those Fe-based LDHs are distinguished candidates considering their high...

Crystallographic and Geometrical Dependence of Water Oxidation Activity in Co-Based Layered Hydroxides

“…Once the LH phases have been structurally and electronically characterized, we proceed with the analysis of their electrochemical performance in terms of the OER by measuring the water oxidation in a three-electrode cell in alkaline media (1 M KOH aqueous solution). For the sake of clarity, glassy carbon has been employed to avoid hidden catalyst–electrode interactions …”

“…For the sake of clarity, glassy carbon has been employed to avoid hidden catalyst−electrode interactions. 13 As a first step, cyclic voltammetry (CV) measurements were performed in order to drive the activation of the electroactive centers. As it is possible to observe in Figure 4, the peaks ascribable to the Co redox processes display a characteristic shape depending on their local environments (chemical identity), as well as a specific continuous increment during the successive cycles.…”

“…Since the first report of a layered hydroxide (LH) for electrochemical water splitting, enormous progress has been achieved to improve the electrochemical performance of these earth-abundant two-dimensional compounds which compete favorably with the benchmark based on precious metal oxides such as Ir and Ru. Along this front, several parameters have been investigated: the influence of different morphologies, − interlayer spaces, metallic compositions, − clustering, and even structural instability of the layers during the water-splitting activity . In general, the catalytic enhancements are usually a consequence of the increment of the electrochemical surface areas, the capability to adsorb OH – ions, the diffusion properties, and/or the intrinsic activities of electroactive sites .…”

Influence of Crystallographic Structure and Metal Vacancies on the Oxygen Evolution Reaction Performance of Ni‐based Layered Hydroxides**

“…After the structural and electronic description, we performed the electrochemical characterisation of all the samples under alkaline oxygen evolution reaction (OER) conditions, by employing a three‐electrode cell (glassy carbon electrode to avoid catalyst‐electrode transformation) [52] and using 1 M KOH solution with a purity of 99.98 % (Figure 4). Firstly, we proceeded by activating the electroactive material through 30 cyclic voltammetries at a scan rate of 50 mV/s.…”

Synthesis of NiFe-layered double hydroxides using triethanolamine-complexed precursors as oxygen evolution reaction catalysts: effects of Fe valence

“…[17][18][19] Hence, numerous strategies have been developed to further optimize the electrocatalytic performance of NiFe-LDH, including morphology modulation, anion exchange or intercalation, heteroatom doping or substitution, and defect engineering. [20][21][22][23][24][25] Liu et al synthesized oxygen vacancy-rich hierarchical NiFe-LDH microtubes assembled using twodimensional nanosheets via a template-assisted strategy as a way to increase the number of catalytically active sites. 26 Wu et al reported a surface strategy to manipulate the coordina-tively unsaturated metal sites of NiFe-LDH to enhance the OER activity of the catalyst by using an optimized amount of ammonium fluoride (NH 4 F) as a metal-complexing agent.…”