Interface Engineering Induced Electrocatalytic Behavior in Core-Shelled CntsNip2/Nbp Heterostructure for Highly Efficient Overall Water Splitting

In this work, core-shell heterostructure catalyst by NiP2/NiP nanosheets shelled carbon nanotubes supported on three-dimensional framework were prepared by new effective approach. Benefiting from the unique morphological feature of carbon nanotubes architecture, the synergy of inner carbon nanotubes and outer NiP2/NiP nanosheets, and the good couple interactions at interface between NiP2 and NbP phases, this electrocatalyst showed low overpotential of 137.0 and 248.2 mV for HER and OER at a current density of 20 mA cm−2, respectively. These overpotentials were one of the smallest values of noble-metal-free electrocatalyst for HER and OER in alkaline electrolyte. Moreover, when the advanced catalyst was assembled in two-electrode configuration for full water electrolysis, a very low cell voltage of 1.51 V was required to achieve 10 mA cm−2 current density and a higher current density of 100 mA cm-2 was reached at a cell voltage of only 2.32 V