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

Abstract

High-performance bifunctional electrocatalysts for both HER (hydrogen evolution reaction) and OER (oxygen evolution reaction) are very pivotal for large-scale production of H 2 by water splitting. Herein, a series of novel hierarchical Co 2 P- x /Ni 2 P- 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 Co 2 P nanowires and Ni 2 P nanosheets , the optimal Co 2 P-1/Ni 2 P-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 Co 2 P-1/Ni 2 P-1 @NF || Co 2 P-1/Ni 2 P-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. • Co 2 P-x/Ni 2 P-y @ NF was fabricated and used as bifunctional catalytic electrodes for water splitting. • The Co 2 P-1/Ni 2 P-1 @ NF exhibited admirable catalytic ability for both HER and OER in alkaline solution. • The water electrolysis device based on Co 2 P-1/Ni 2 P-1 @ NF || Co 2 P-1/Ni 2 P-1 @ NF only needs 1.63 V to offer 10 mA cm-2.