Durable Seawater Electrolysis through the Synergistic Effect of Oxidized MXene/Nickel Ferrite Composite Electrocatalyst

Seawater electrolysis is a promising approach for sustainable and environmentally friendly hydrogen production, primarily because it has zero carbon emissions and mitigates freshwater resource scarcity. However, seawater electrolysis requires high selectivities for both the oxygen and hydrogen evolution reactions in an environment characterized by a high concentration of impurity ions, particularly Cl^-. In addition, the corrosion resistance of materials to byproducts is essential. These challenges limit the widespread adoption of seawater electrolysis. Herein, we validate the excellent Cl^- repelling property of oxidized TiO_x/C composite with Ti impregnated into nickel ferrite by high-energy ball-milling of MXene. The developed nickel ferrite and TiO_x/C composites are utilized as anodes of anion exchange membranes and exhibit high stability in seawater electrolysis. Measurement results show a current density of 0.85 A cm^-2 at 1.8 V_cell, which is 5 times the activity of pristine nickel ferrite (0.21 A cm^-2 at 1.8 V_cell). More significantly, in terms of the durability of anion exchange membranes for seawater electrolysis, the nickel ferrite and TiO_x/C composite demonstrates long-term durability (250 h) twice that of pristine nickel ferrite (120 h). This work confirms the Cl^- repelling effect of oxidized MXene and its successful utilization in anion exchange membranes for seawater electrolysis.