Laser-Induced NiFeO<sub><i>x</i></sub> Nanolayer Enables Durable and Efficient Seawater Electrolysis at Industrial Current Densities
Ziyang Duan, Yang Liu, Benzhi Wang, Zhihao Zhang, Quan Yuan, Yongjian Fang, Yali Zhang, Yali Zhang, Hyung Mo Jeong, Yinggan Zhang, Yinggan Zhang, Jonghwan Suhr
Abstract
Seawater electrolysis is an emerging pathway for sustainable hydrogen production, yet long-term operation under industrial current densities is severely constrained by chloride-induced corrosion and catalyst degradation. Here, we introduce a laser-induced interface engineering strategy that leverages the rapid thermal dynamics of laser powder bed fusion (LPBF) to construct a ∼5 nm nonstoichiometric NiFeO x nanolayer epitaxially grown to a NiFe alloy substrate. This in situ fabricated nanolayer functions as a multifunctional interface, selectively adsorbing OH – ions through stable metal–oxygen (M–O) bonding, thereby suppressing Cl – -driven surface degradation while simultaneously accelerating the oxygen evolution reaction (OER) kinetics by lowering the Gibbs free energy barrier of the OER intermediates (*OH) from 0.61 to 0.48 eV. As a result, the NiFe with oxide layer (NiFe-OL) electrode achieves an overpotential of 238 mV at 10 mA cm –2 in simulated seawater, showing a marked 84 mV reduction compared to the bare NiFe alloy electrode, and maintains stable operation for over 1000 h at 1 A cm –2 in alkaline seawater. This represents more than 25 times longer operational stability than the bare NiFe electrode, which fails after only ∼20 h under identical conditions. In particular, the laser-formed functionally integrated oxide nanointerface delivers a distinctive combination of corrosion resistance and electrochemical kinetics. Our findings demonstrate a robust seawater electrolysis electrode and demonstrate the applicability of scalable interface engineering for application in corrosive electrochemical systems.