In situ fabrication of low-crystallinity (Ni,Fe)xSy nanosheet arrays via room-temperature corrosion engineering toward efficient oxygen evolution

Abstract

The field of room-temperature corrosion engineering has emerged as a promising avenue for the controlled synthesis of functional nano-materials, owing to its simplicity and potential for scalability. To date, room temperature corrosion engineering has been skillfully applied and successfully used to synthesizee transition metal (oxy)hydroxides. However, the synthesis of transition metal sulfides via room-temperature corrosion encounters challenges due to the low standard electrode potential and sluggish corrosion kinetics of S/Sn2-. Here, we have successfully initiated the oxidation behavior of S22- on Ni3Fe7 foam by adjusting the pH of the aqueous solution (containing (NH4)2SO4 and Na2S2), and subsequently synthesized low-crystallinity (Ni,Fe)xSy nanosheet arrays with significant lattice distortion and amorphous characteristics. Experimental studies combined with theoretical calculations have confirmed Fe within the (Ni,Fe)xSy structure functions as a highly active site while simultaneously expediting the lattice oxygen mechanism, thus yielding a remarkably efficient OER performance.