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

Designing and preparing multimetallic compounds with special structure and without using any template and shape-directing agent is a challenge. Herein, nickel-iron-chromium compound/stainless steel foil (NICC/SSF) electrocatalysts with a novel flower-like nanostructure is synthesized by one-step cathodic eletrodeposition method with sacrificial anode. The as-fabricated NICC/SSF electrode as the earth-abundant and high-efficiency bifunctional electrocatalyst exhibits favorable electrocatalytic performance toward hydrogen evolution reaction and oxygen evolution reaction in alkaline solutions, which specifically presents only small overpotentials of 85 mV and 274 mV attaining a current density of 10 mA cm-2, respectively. The particular vegetative flower-like nanostructures with highly conductive flocculent clusters could promote sufficiently exposure of active sites and optimize electronic configuration, which is beneficial to facilitate the catalytic performance. In consideration of the well-defined bifunctionality, the full alkaline electrolyzer is constructed by two identical NICC/SSF electrodes. Notably, the NICC/SSF two-electrode electrolyzer for water splitting generates a low onset potential of ~1.56 V and the cell voltage of 1.60 to reach the 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.