Reconstructed β-NiOOH enabling highly efficient and ultrastable oxygen evolution at large current density

•Electronic interaction at FeS2@NiS2 enable the reconstruction of β-NiOOH in OER.•β-NiOOH couples with FeOOH to form the heterostructure as actual OER active phase.•Electronic rearrangement at β-NiOOH@FeOOH reduce energy barriers of O* formation.•The electrodes exhibit excellent performance and stability for large-current OER.