Ferrum-Molybdenum Dual Incorporated Cobalt Oxides as Efficient Bifunctional Anti-Corrosion Electrocatalyst for Seawater Splitting

Electrochemical seawater splitting is a potentially attractive technology for sustainable hydrogen production; however, its implementation is severely hindered by the lack of active and anti-corrosion catalysts. Here, a monolithic Fe-Mo-Co-O nanosheet assembly is reported, comprising Fe-doped Co2Mo3O8/MoO3/Co3O4 hybridized nanosheets decorated on nickel foam (FMCO/NF). The intelligent combination of corrosion-resistant Mo-O species and highly active Fe dopant afford FMCO/NF with high activity and durability for water splitting in both freshwater, simulated seawater, and real seawater media. Specifically, the symmetric FMCO/NF-based alkaline electrolyzer generates 10 mA cm−2 at a low voltage of 1.58 V, outperforming the benchmark IrO2/NF||Pt/C/NF and many non-noble metal-based catalysts. Moreover, an alkaline seawater electrolyzer with low cell voltage, good durability, and high Faradaic efficiency was manufactured by using monolithic FMCO/NF as both cathode and anode. This work offers a new path toward the design of highly efficient and anti-corrosion catalysts for hydrogen generation from seawater.