Constructing P-CoMoO4@NiCoP heterostructure nanoarrays on Ni foam as efficient bifunctional electrocatalysts for overall water splitting

Improving catalytic activity and durabilty through the structural and compositional development of bifunctional electrocatalysts with low cost, high activity and stability is a challenging issue in electrochemical water splitting. Herein, we report the fabrication of heterostructured P-CoMoO4@NiCoP on a Ni foam substrate through interface engineering, by adjusting its composition and architecture. Benefitting from the tailored electronic structure and exposed active sites, the heterostructured P-CoMoO4@NiCoP/NF arrays can be coordinated to boost the overall water splitting. In addition, the superhydrophilic and superaerophobic properties of P-CoMoO4@NiCoP/NF make it conducive to water dissociation and bubble separation in the electrocatalytic process. The heterostructured PCoMoO4@NiCoP/NF exhibits excellent bifunctional electrocatalysis activity with a low overpotential of 66 mV at 10 mA cm-2 for HER and 252 mV at 100 mA cm-2 for OER. Only 1.62 V potential is required to deliver 20 mA cm-2 in a two-electrode electrolysis system, providing a decent overall water splitting performance. The rational construction of the heterostructure makes it possible to regulate the electronic structures and active sites of the electrocatalysts to promote their catalytic activity.