Rational design and construction of low-cost overall water splitting catalysts with high efficiency is of great significance to the green chemistry industry. Herein, a CoFeP/NC@CoP/Ni2P heterostructure is constructed via phosphiding CoFe-Prussian blue analogue@NiCo-precursor (CoFe-PBA@NiCo-Pre). This novel synthesis strategy can be used to prepare heterostructures, which significantly promote charge transfer due to a moderately regulated electronic structure and a strongly coupled heterointerface for electrocatalysis. Notably, the as-prepared CoFeP/NC@CoP/Ni2P heterostructure catalyst shows outstanding performances with small overpotentials of 256 mV for the oxygen evolution reaction and 177 mV for the hydrogen evolution reaction at 10 mA cm−2, respectively. Besides, when CoFeP/NC@CoP/Ni2P is used as anode and cathode catalysts, the cell voltage is only 1.66 V at 50 mA cm−2. This work provides a novel perspective for the design and construction of heterostructure electrocatalysts for water splitting.
