Enabling stable seawater electrolysis: Anti-corrosive Mo-modified NiFe anode for efficient electrochemical oxygen evolution

The electrolysis of seawater represents a promising route for sustainable hydrogen production, yet it remains severely hindered by chloride-induced corrosion and competing side reactions at the anode. In this study, we develop a robust NiFe layered double hydroxide (LDH) anode modified with molybdate (MoO 4 2− ) via a simple ion intercalation strategy, which significantly enhances both the activity and durability of the oxygen evolution reaction (OER) in alkaline seawater. Systematic experimental and in-situ spectroscopic analyses reveal that intercalated MoO 4 2− induces electron delocalization around Ni/Fe sites, elevating their oxidation states and facilitating a lattice oxygen-mediated reaction pathway. This electronic modulation not only accelerates OER kinetics but also effectively shields active sites from chloride attack. The optimized NiFe LDH-MoO 4 2- electrode achieves outstanding performance with low overpotentials of 252, 284 and 312 mV at current densities of 100, 500 and 1000 mA cm −2 , respectively, and exhibits remarkable long-term stability for 220 h with 93 % retention. When integrated into a two-electrode seawater electrolyzer, the system requires only 1.65, 1.74 and 1.87 V to deliver 0.5, 1.0 and 2.0 A cm −2 , and operates stably over 180 h. This work offers an effective anti-corrosion engineering strategy, paving the way for industrial-scale seawater electrolysis.