F-doping induced low-barrier interface in RuNi-F-NiMoO heterostructure for efficient urea-assisted hydrogen evolution via seawater splitting.

Amidst the escalating global energy crisis, the quest for efficient electrocatalysts for water splitting has become increasingly imperative. Herein, we develop a bifunctional electrocatalyst comprising RuNi alloy nanoparticles anchored on fluorine-doped NiMoO nanorods (RuNi-F-NiMoO), engineered for efficient hydrogen production from seawater and urea oxidation reactions. The strategic F doping effectively reduces the difference in work functions and modulates the electronic interactions between the RuNi alloy and the NiMoO substrate, enhancing electron transfer kinetics and significantly improving electrocatalytic activity and stability. Notably, the RuNi-F-NiMoO exhibits outstanding hydrogen evolution reaction performance in both alkaline freshwater (248 mV at 1 A cm) and alkaline seawater (277 mV at 1 A cm), enabling industrial-scale high-current-density hydrogen production and maintaining durability over 1,000 h at 100 mA cm in alkaline seawater. Furthermore, RuNi-F-NiMoO achieves a current density of 1 A cm at a low potential of 1.59 V during the urea oxidation reaction, and facilitates a complete urea total cracking system operating at 1.88 V at 1 A cm in alkaline seawater, thereby reducing energy consumption for hydrogen production. This work offers a promising avenue for the development of efficient electrocatalysts in seawater electrolysis and urea oxidation, potentially advancing sustainable energy technologies.