Variable-valence ion and heterointerface accelerated electron transfer kinetics of electrochemical water splitting

The electron transfer from OER intermediates via the amorphous NiFeOOH shell was efficiently accelerated by the variable-valence V 3+/4+ acceptor at core@shell interface and the heterojunction effect in Ni 3 Fe 1− x V x /Ni 3 Fe 1− x V x N core, significantly facilitating the OER performance.