Synthesis of flower-like nickel–iron–chromium nanostructure compound deposited stainless steel foil as an efficient binder-free electrocatalyst for water splitting

Abstract

Designing and preparing multimetallic compounds with special structures and without using any template and shape-directing agent is a challenge. Herein, a nickel-iron-chromium compound/stainless steel foil (NICC/SSF) electrocatalyst with a novel flower-like nanostructure is synthesized by a one-step cathodic electrodeposition method with a sacrificial anode. The as-fabricated NICC/SSF electrode as an earth-abundant and high-efficiency bifunctional electrocatalyst exhibits favorable electrocatalytic performance toward the hydrogen evolution reaction and oxygen evolution reaction in alkaline solutions and specifically requires only small overpotentials of 85 mV and 274 mV for attaining a current density of 10 mA cm⁻², respectively. The particular vegetative flower-like nanostructures with highly conductive flocculent clusters could promote sufficient exposure of active sites and optimize the electronic configuration, which is beneficial to facilitate the catalytic performance. In consideration of the well-defined bifunctionality, a full alkaline electrolyzer is constructed with two identical NICC/SSF electrodes. Notably, the NICC/SSF two-electrode electrolyzer for water splitting requires a low onset potential of ∼1.56 V and a cell voltage of 1.60 to reach a current density of 10 mA cm⁻², which is ascribed to the synergistic interactions between the metal species by metal–metal charge transfer. The presented strategy offers a facile approach for developing efficient, stable, and low-cost electrocatalysts for realizing large-scale water splitting.