Nonprecious bimetallic NiFe ‐layered hydroxide nanosheets as a catalyst for highly efficient electrochemical water splitting

Abstract

Summary It has become highly necessary to advance stable, cost‐effective, and energy‐efficient hydrogen production using non‐precious metal‐based water electrolysis to replace the increasing demand for fossil fuels and maintain environmental safety. Herein, we present the synthesis of non‐precious bimetallic Ni1‐xFex‐layered hydroxide nanosheet films by using a chemical‐bath deposition technique for use as oxygen evolution reaction (OER) catalysts for electrochemical water electrolysis. Remarkably, the optimized Ni0.50Fe0.50‐layered hydroxide electrode exhibited excellent OER activity in 1 M potassium hydroxide electrolyte while having a low overpotential of 239.7 mV at a current density of 10 mA cm−2 with a small Tafel slope of 38.02 mV dec−1. It was electrochemically stable over 100 hours of continuous OER operation, thereby showing its excellent electrochemical stability. The results from a post‐OER study reveal that catalytically active OER sites are associated with the formation of a nickel oxyhydroxide intermediate on the surface of the electrode. The maximum synergy among good electronic conductivity, high diffusion coefficient, and enlarged electrochemically active sites was obtained by optimizing the Ni/Fe ratio and thereby, the OER activity.

Solvent modulated self‐assembled VS 2 layered microstructure for electrocatalytic water and urea decomposition

“…14,15 Hence, designing and fabricating universally efficient, cheap, and earth-abundant material-based catalysts have become a top priority for significant improvement in electrochemical water and urea splitting to obtain hydrogen and treat urea-rich wastewater simultaneously. Up to now, several earthabundant metals-based electrocatalysts has been developed, including metal oxide, 16 metal hydroxide, 17 metalorganic framework (MOF), [18][19][20] metal phosphide, 21 metal-sulfides, 22,23 metal nitrides, 24 metal carbides, 25 and so on. However, the majority of the catalysts do not have enough performance when utilized for overall urea-splitting.…”

Electrodeposited bimetallic microporous MnCu oxide electrode as a highly stable electrocatalyst for oxygen evolution reaction

“…3,4 Thus, the OER needs to be focused more because it is the main bottleneck in the electrocatalysis process due to its high overpotential, sluggish kinetics due to complex electron-proton transfer. [8][9][10][11][12] Precious elements such as Pt, ruthenium (IV) oxide (RuO 2 ), and iridium (IV) oxide (IrO 2 ) have incredible electrocatalytic properties for oxygen reduction reaction (ORR) and OER. However, these valuable metals are very expensive and hardly accessible on Earth, which hinders their use for mass production.…”