Transition metal sulfide and nickel-iron layered double hydroxide nanohybrids for promising alkaline seawater oxidations

Abstract

Direct seawater electrolysis is of great significance to produce green hydrogen using sustainable resources which can be applicable for water-scarce regions. Herein, a nanohybrid consisted of transition metal sulfide and layered double hydroxide is designed with aims to modify unfavorable surface electronic state of nickel–iron LDH (NF-LDH) for seawater oxidation. Specifically, Mo-doped NiS2 is deposited onto the self-standing two dimentional NF-LDH nanosheets, (Ni,Mo)S2//NF-LDH 300, using an e-beam evaporator. Physical deposition technique. The designed (Ni, Mo)S2//NF-LDH 300 catalyst proves a superior catalytic activity and stability for seawater oxidation under alkaline electrolyte. The deposited transition sulfide layer induces an improved charge transfer as well as reaction kinetics for the (Ni, Mo)S2//NF-LDH 300. Further, adsorptions of chloride anions at the surface is substantially suppressed due to the deposited transition metal sulfide effectively preventing chloride corrosions. The (Ni, Mo)S2//NF-LDH 300 demonstrates practical level of performance for alkaline seawater oxidation, shedding lights on our catalyst design strategy for direct seawater electrolysis.