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

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 heterogeneousstructured catalyst is constructed by depositing NiFe-layered double hydroxides(NiFe-LDH)on the substrate of MXene(V_(2)CT_(x))modified Ni foam(NF),and abbreviated as NiFe-LDH/V_(2)CT_(x)/NF.As demonstrated,owing to the intrinsic negative charge characteristic of V_(2)CT_(x),chlorine ions are denied entry to the interface between NiFeLDH and V_(2)CT_(x)/NF substrate,thus endowing NiFe-LDH/V_(2)CT_(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 V_(2)CT_(x) can respectively enlarge the electrochemical active surface area and guarantee fast charge transfer,thereby synergistically promoting the catalytic performance of NiFe-LDH/V_(2)CT_(x)/NF in both deionized water electrolyte(261 m V at 100 m A 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.

In-situ Generation of Hydroxyl Layers in Coo@FeSe_(2) Catalyst for High Selectivity Seawater Electrolysis

Seawater electrolysis holds great promise for hydrogen production in the future,while the development of anodic catalysts has been severely hampered by the side-reaction,chloride evolution reaction.In this work,nano-flower-cluster structured Coo@FeSe_(2)/CF catalysts are synthesized via a scalable electrodeposition technique,and the performance is systematically studied.The oxygen evolution reaction(OER)overpotential of Co0@FeSe_(2)/CF is 267 mV at 100 mA.cm^(-2),which is significantly lower than that of the IrO_(2) catalyst(435 mV).Additionally,the catalyst shows high selectivity for OER(97.9%)and almost no loss of activity after a durability test for 1100 h.The impressive performance is attributed to the dense rod-like structure with abundant active centers after electrochemical activation and the in-situ generated CoOOH and FeOOH that improve the catalytic activity of the catalyst.The synergistic effect induced bythenon-uniform structureendows the catalyst with excellent stability.