Dendrimer-Ni-Based Material: Toward an Efficient Ni–Fe Layered Double Hydroxide for Oxygen-Evolution Reaction

Abstract

Ni/Fe oxides are among the most widely used catalysts for water splitting. This paper outlines a new approach to synthesize Ni−Fe layered double hydroxides (Ni−Fe LDHs) for oxygen-evolution reaction (OER). Herein, we show that a dendrimer with carboxylate surface groups (generation 3.5) could react with Ni(II) ions to form a precatalyst for OER. During electrochemical OER, this precatalyst converted to Ni−Fe LDH, which is an efficient catalyst toward OER in the presence of Fe(III) ions. The catalyst was characterized by a number of methods and applied for OER using fluorinedoped tin oxide (FTO), Au, Pt, Ni foam, and glassy carbon electrodes. The catalyst shows a current density of 100 mA/cm 2 on the surface of the Ni foam, using only 297 mV overpotential and with the Tafel slope of 60.8 mV/decade. A current density of 50 mA/cm 2 on the surface of Au or Pt requires 333 and 317 mV overpotentials, respectively. The slopes of the Tafel plots for the catalyst on Au, GC, and Pt are 52.5, 47.1, and 37.4 mV/decade, respectively. The dendrimer resulted in a large dispersibility and an increase in active sites of Ni−Fe LDH, as well as the formation of Ni−Fe LDH.

Electronically coupled layered double hydroxide/MXene quantum dot metallic hybrids for high‐performance flexible zinc–air batteries

“…Two‐dimensional (2D) nanomaterials are considered as promising electrocatalysts for energy conversion and storage applications owing to their abundant exposed active sites, large surface area, and unique surface chemistry. 2D Ni‐ and/or Fe‐containing layered double hydroxides (NiFe‐LDH) exhibit remarkable catalytic activity for the OER 16–21 but are limited by their low ORR performance, which restricts the rechargeability of ZABs. Integrating heteroatom‐doped carbon‐based materials is an effective strategy to endow NiFe‐LDH‐based electrocatalysts with bifunctional activities 22–26 .…”

Magnetically Recoverable Nanoparticulate Catalysts for Cross-Coupling Reactions: The Dendritic Support Influences the Catalytic Performance

“…Dendrimers are one of the most versatile macromolecular platforms for the stabilization of catalytically active metal complexes or nanoparticles (NPs) because of their hyperbranched architecture [36]. Dendrimer-based catalysts have been successfully utilized in hydrogenation [37][38][39], oxygen evolution reaction [40], oxidation [41,42], and cross-coupling reactions [43][44][45][46].…”

Sodium Cobalticarborane: A Promising Precatalyst for Oxygen Evolution Reaction

“…Fuel production toward the storage of sustainable energy is limited by the lack of access to low-cost electrons . The oxygen evolution reaction (OER) generates protons and electrons and, thus, is an essential reaction for fuel production. − IrO 2 and RuO 2 were reported as state-of-the-art catalysts for OER . Commercially available micrometer-thickness IrO 2 -RuO 2 deposited on titanium support material are rarely far more expensive than 6 USD/100 cm 2 , but their scarcity in the Earth’s crust is a challenging issue for widespread application.…”

“…Finding scalable, efficient, and stable OER catalysts working at low overpotentials for OER is an interesting but challenging issue . First-row transition metal compounds were considered as effective catalysts for OER. − Among these metal compounds, Co compounds are efficient catalysts for OER. − Although Co is not as low-cost as Fe, Mn, or Cu, some strategies have been proposed to decrease the consumption of this element in preparing an electrode. Covering an inexpensive substrate used as an electrode with small amounts of nanosized cobalt oxide is among these strategies. − …”