Electrochemical water splitting into hydrogen and oxygen is a promising strategy for future renewable energy conversion devices.The oxygen evolution reaction (OER) is considered as the bottleneck reaction in an overall water splitting system because it involves 4e-and 4H+ transfer processes.Currently,it is highly desirable to explore low-cost alternative catalysts for OER at ambient conditions.Herein,we report for the first time that nickel phosphide (Ni2P) nanosheets can be facilely grown on Fe foam (FF) as an efficient electrocatalyst for OER with excellent durability and catalytic activity under alkaline conditions.To reach a current density of 10mA/cm2,the Ni2P-FF catalyst required a low overpotential of only 198 mV for OER.The catalyst\'s high OER activity and durability were well maintained at a high current density.The required overpotentials were only 267 and 313 mV to achieve the current densities of 100 and 300mA/cm2,respectively.The combination of low-cost Fe foam with Ni2P provides a promising low-cost catalyst for large-scale application of electrocatalytic water splitting.