S-CeNiFe LDHs decorated with sacrificial NiS2: A robust electrocatalyst for alkaline seawater splitting

S-CeNiFe LDH/NiS 2 enhances the durability of seawater splitting. • Sacrificial NiS 2 nanoparticles protect catalyst from Cl- corrosion. • Sulphuration and Ce atoms mitigate the loss of Ni/Fe during seawater splitting. • Downshifted d-band optimizes the OER and suppresses ClER. The development of efficient and stable electrocatalysts to overcome chloride corrosion is crucial for sustainable hydrogen production via alkaline seawater electrolysis. Herein, a Ce-doped NiFe LDH heterostructure (S-CeNiFe LDH/NiS 2 ) was synthesized and exhibited enhanced bifunctional activity for both the oxygen and hydrogen evolution reactions (OER/HER) in alkaline seawater (1 M KOH + natural seawater), along with seawater corrosion resistance by the sacrificial NiS 2 nanoparticles. The optimized S-Ce 0.4 NiFe LDH/NiS 2 requires low overpotentials of only 310 mV for OER and 290 mV for HER at 100 mA cm -2 , surpassing both unsulfurated CeNiFe LDH and bare NiFe LDH. It also shows smaller Tafel slopes and maintains excellent stability over 100 h with minimal decay. The sacrificial role of NiS 2 in protecting LDHs is confirmed by its structural and chemical evolution alongside attenuated seawater decomposition. Performance enhancement stems from heterostructure synergy: expanded surface area, accelerated charge transfer, Ce doping-induced electronic modulation, and conductive NiS 2 for HER. This work addresses critical challenges in direct seawater splitting for scalable hydrogen production. Download: Download high-res image (264KB) Download: Download full-size image