Seawater electrolysis holds tremendous promise for the generation of green hydrogen (H2 ). However, the system of seawater-to-H2 faces significant hurdles, primarily due to the corrosive effects of chlorine compounds, which can cause severe anodic deterioration. Here, a nickel phosphide nanosheet array with amorphous NiMoO4 layer on Ni foam (Ni2 P@NiMoO4 /NF) is reported as a highly efficient and stable electrocatalyst for oxygen evolution reaction (OER) in alkaline seawater. Such Ni2 P@NiMoO4 /NF requires overpotentials of just 343 and 370 mV to achieve industrial-level current densities of 500 and 1000 mA cm-2 , respectively, surpassing that of Ni2 P/NF (470 and 555 mV). Furthermore, it maintains consistent electrolysis for over 500 h, a significant improvement compared to that of Ni2 P/NF (120 h) and Ni(OH)2 /NF (65 h). Electrochemical in situ Raman spectroscopy, stability testing, and chloride extraction analysis reveal that is situ formed MoO4 2- /PO4 3- from Ni2 P@NiMoO4 during the OER test to the electrode surface, thus effectively repelling Cl- and hindering the formation of harmful ClO- .
Keywords: NiMoO4 layer; PO43−/MoO42− ionic layer; chlorine exclusion strategy; in situ Raman spectroscopy; seawater oxidation.
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