Design of highly active and durable oxygen evolution catalyst with intrinsic chlorine inhibition property for seawater electrolysis

Abstract

High-efficiency seawater electrolysis is impeded by the low activity and low durability of oxygen evolution catalysts due to the complex composition and competitive side reactions in seawater. Herein, a heterogeneous-structured catalyst is constructed by depositing NiFe-layered double hydroxides (NiFe-LDH) on the substrate of MXene (V₂CT_x) modified Ni foam (NF), and abbreviated as NiFe-LDH/V₂CT_x/NF. As demonstrated, owing to the intrinsic negative charge characteristic of V₂CT_x, chlorine ions are denied entry to the interface between NiFe-LDH and V₂CT_x/NF substrate, thus endowing NiFe-LDH/V₂CT_x/NF catalyst with high corrosion resistance and durable stability for 110 ​h at 500 ​mA ​cm⁻². Meanwhile, the two-dimensional structure and high electrical conductivity of V₂CT_x can respectively enlarge the electrochemical active surface area and guarantee fast charge transfer, thereby synergistically promoting the catalytic performance of NiFe-LDH/V₂CT_x/NF in both deionized water electrolyte (261 ​mV at 100 ​mA ​cm⁻²) and simulated seawater electrolyte (241 ​mV at 100 ​mA ​cm⁻²). This work can guide the preparation of oxygen evolution catalysts and accelerate the industrialization of seawater electrolysis.