Anion‐Modulated HER and OER Activities of 3D Ni–V‐Based Interstitial Compound Heterojunctions for High‐Efficiency and Stable Overall Water Splitting

Abstract Overall water splitting driven by a low voltage is crucial for practical H 2 evolution, but it is challenging. Herein, anion‐modulation of 3D Ni–V‐based transition metal interstitial compound (TMIC) heterojunctions supported on nickel foam (Ni 3 N‐VN/NF and Ni 2 P‐VP 2 /NF) as coupled hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts for efficient overall water splitting is demonstrated. The heterointerface in Ni 3 N‐VN has a suitable H* absorption energy, being favorable for enhancing HER activity with onset overpotential (η onset ) of zero and Tafel slope of 37 mV dec −1 in 1 m KOH (close to that of Pt/C/NF). For the OER, the synergy of Ni 2 P‐VP 2 with oxide species…

• NN
  National Natural Science Foundation of China

  Awards: 21571054, 21805073, 21771059, 21631004
• NS
  Natural Science Foundation of Heilongjiang Province

  Award: QC2018013
• NK
  National Key Research and Development Program of China