Construction of hierarchical Co2P/Ni2P heterostructures on Ni foam as efficient bifunctional electrocatalyst for overall water splitting

High-performance bifunctional electrocatalysts for both HER (hydrogen evolution reaction) and OER (oxygen evolution reaction) are very pivotal for large-scale production of H2 by water splitting. Herein, a series of novel hierarchical Co2P-x/Ni2P-y @ NF samples have been fabricated via a simple synthesizing method and employed as bifunctional catalytic electrodes for overall water splitting. Owing to the hierarchical heterostructure and interaction between the Co2P nanowires and Ni2P nanosheets, the optimal Co2P-1/Ni2P-1 @NF sample exhibited remarkable catalytic ability for both HER and OER in alkaline solution (79 mV and 310 mV at 10 mA cm-2, respectively.). As a result, the water electrolysis device based on Co2P-1/Ni2P-1 @NF || Co2P-1/Ni2P-1 @NF system only needs 1.63 V to offer 10 mA cm-2 and keeps excellent durability for 40 h, demonstrating its great practical application value for overall water splitting.