A Laser Synthesis Strategy to Boost Oxygen Evolution Kinetics on Stainless Steel-Based Catalyst via Dual-Metal Segmentally Coordinated Reaction Centers for Efficient Alkaline Water Splitting.

The fabrication of efficient, stable, and noble-metal-free electrocatalysts for the hydrogen energy field has been of great interest, but still faces numerous challenges, especially in the development of fast and convenient strategies. This study reports a state-of-the-art strategy for the ultrafast preparation of spinel-type oxide self-supporting catalysts on stainless steel by ultrafast two-step laser synthesis. The self-supporting catalytic electrode not only possesses remarkable superhydrophilic/superaerophobic properties but also the constructed (Ni, Fe, Co)(Fe, Cr)O·(OH)@SS304 microcone array catalyst also demonstrates a superior oxygen evolution reaction (OER) performance with a low overpotential of 130 mV at 10 mA cm, a Tafel slope of 34.0 mV dec, and outstanding long-term stability (a negligible overpotential decay of ≈5% at 10 mA cm for over 88 h). The laser-fabricated catalysts exhibit optimal performances, surpassing that of the best previously reported stainless steel-based OER catalysts. First-principles calculations also reveal that the reaction mechanism of the as-prepared catalyst is affiliated with the oxide path mechanism dominated by the exposed (220) crystal facet, and dual-metal segmentally coordinated reaction centers effectively reduce the oxygen evolution energy barriers, boosting the OER kinetics. This work may open up a new path to design multi-metal-based self-supporting catalysts for hydrogen energy applications.