MXene-Assisted NiFe sulfides for high-performance anion exchange membrane seawater electrolysis.

Abstract

Anion exchange membrane seawater electrolysis is vital for future large-scale green hydrogen production, however enduring a huge challenge that lacks high-stable oxygen evolution reaction electrocatalysts. Herein, we report a robust OER electrocatalyst for AEMSE by integrating MXene (Ti₃C₂) with NiFe sulfides ((Ni,Fe)S₂@Ti₃C₂). The strong interaction between (Ni,Fe)S₂ and Ti₃C₂ induces electron distribution to trigger lattice oxygen mechanism, improving the intrinsic activity, and particularly prohibits the dissolution of Fe species during OER process via the Ti-O-Fe bonding effectively, achieving notable stability. Furthermore, the good retention of sulfates and the abundant groups of Ti₃C₂ provide effective Cl^- resistance. Accordingly, (Ni,Fe)S₂@Ti₃C₂ achieves high OER activity (1.598 V@2 A cm^-2) and long-term durability (1000 h) in seawater system. Furthermore, AEMSE with industrial current density (0.5 A cm^-2) and durability (500 h) is achieved by (Ni,Fe)S₂@Ti₃C₂ anode and Raney Ni cathode with electrolysis efficiency of 70% and energy consumption of 48.4 kWh kg^-1 H₂.