Synergistic Coupling Effect and Anionic Modulation of CoFe LDH@MXene for Triggered and Sustained Alkaline Water/Seawater Electrolysis

The application of seawater splitting is crucial for hydrogen production; therefore, efficient electrocatalysts are necessary to prevent chlorine evolution and severe corrosion. A synergistic method is employed on CoFe LDH by integrating a conductive Ti 3 C 2 T x MXene layer and subsequently applying anionic modulation. Robust metal‐substrate interaction along with subsequent phosphidation facilitates efficient electron transfer and optimises the electronic structure of Co and Fe sites. The CoFe−P−1000@Ti 3 C 2 T x /CC demonstrates commendable electrochemical performance, requiring overpotentials of 106.6 mV and 276 mV for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA cm −2 in 1 M KOH electrolyte, while 292 mV is necessary for OER in a simulated seawater electrolyte (1 M KOH+0.5 M NaCl). Furthermore, the CoFe−P−1000@Ti 3 C 2 T x /CC exhibits an encouraging cell voltage of 1.59 V (j=10 mA cm −2 ) for comprehensive alkaline seawater splitting, maintaining exceptional stability for over 50 hours.