V and Fe dual-doping modulated the electronic structures of Ni3S2/Ni(OH)2 for ampere-level seawater oxidation

The development of versatile oxygen evolution reaction (OER) electrocatalysts for ampere-level seawater electrolysis holds enormous promise for clean energy generation. Still, it is hindered by the competing chlorine evolution and severe chloride corrosion. Herein, the V and Fe dual-doped Ni 3 S 2 /Ni(OH) 2 (VFe-Ni 3 S 2 /Ni(OH) 2 ) heterostructure was fabricated on nickel foam as an OER catalyst for direct seawater electrolysis. The dual-doping of V and Fe optimizes the electronic structure cooperatively, improves conductivity, and enriches active sites of Ni 3 S 2 /Ni(OH) 2 , boosting OER performance at ampere-level current density. The optimal electrode V 0.03 Fe-Ni 3 S 2 /Ni(OH) 2 requires only 385 mV overpotential to arrive 1 A/cm 2 and works stably for over 100 h at 100 mA/cm 2 in seawater electrolyte. The assembled electrolyzer V 0.03 Fe-Ni 3 S 2 /Ni(OH) 2 ||Pt/C exhibited a cell voltage of 1.52 V at 10 mA/cm 2 with a noteworthy stability of 100 h at 100 mA/cm 2 for seawater electrolysis, providing huge potential for hydrogen production from seawater.