Stabilized Hydroxide Mediated Nickel-Based Electrocatalysts for High Current Density Hydrogen Evolution in Alkaline Media

TL;DR

This paper introduces a hydroxide-mediated nickel-based electrocatalyst that achieves high current density hydrogen evolution with low overpotential, demonstrating potential for industrial water splitting applications.

Contribution

It presents a novel charge-engineering strategy to stabilize nickel hydroxide at high current densities, enabling efficient hydrogen evolution in alkaline media.

Findings

Achieves 1000 mA/cm² at 98 mV overpotential

Demonstrates 500 mA/cm² at 1.56 V in water splitting

Shows stabilization of nickel hydroxide via charge redistribution

Abstract

Large scale production of hydrogen by electrochemical water splitting is considered as a promising technology to address critical energy challenges caused by the extensive use of fossil fuels. Although nonprecious nickel-based catalysts work well at low current densities, they need large overpotentials at high current densities that hinders their potential applications in practical industry. Here we report a hydroxide-mediated nickel based electrocatalyst for high current density hydrogen evolution, which delivers a current density of 1000 mA cm-2 at an overpotential of 98 mV. Combined X-ray absorption spectroscopy and high resolution X-ray photoelectron spectroscopy results show charge redistribution of nickel sites caused by Mo and surface FeOx clusters, which can stabilize the surface nickel hydroxide at high current densities for promoting water dissociation step. Such catalyst is synthesized at the metre scale and shows a current density of 500 mA cm-2 at 1.56 V in the overall water splitting, which demonstrate its potential for practical use. This work highlights a charge-engineering strategy for rational design of catalysts that work well at high current densities.