Tip effect-assisted modulation of interfacial charge in FeCoNi LDH/Ni3S2 Mott-Schottky heterojunction for efficient oxygen evolution reaction

Constructing heterojunction is a good method to improve electrocatalytic activity because the heterojunctions can modulate the Fermi level and redistribute charges of the catalysts to accelerate electron transfer . In this study, Ni 3 S 2 nanocones were prepared on nickel foam (NF) by hydrothermal synthesis, and FeCoNi LDH/Ni 3 S 2 Schottky heterojunctions were constructed by electrodeposition of FeCoNi LDH nanosheets onto Ni 3 S 2 nanocones. Electrochemical results demonstrate that FeCoNi LDH/Ni 3 S 2 /NF is an efficient alkaline OER catalyst, the overpotential is 216 mV at 100 mA cm -2 , and it can maintain stable operation for 110 h. The battery voltage of the dual-electrode structure composed of FeCoNi LDH/Ni 3 S 2 /NF and NF at 1 M KOH is 1.61 V at 10 mA cm -2 . The results of XPS show that the FeCoNi LDH/Ni 3 S 2 Schottky heterojunction optimizes the electronic structure of the interface, accelerating electron transfer. Additionally, the enhanced electric field effect at the tip of Ni 3 S 2 further promotes electron transfer in the heterojunction structure. FeCoNi LDH/Ni 3 S 2 Schottky heterojunction exhibits significant OER activity, which provides a method for synthesizing transition metal heterojunction catalysts with low cost and high activity in the future.