Development of inexpensive and high-performance electrocatalysts for water splitting is the major challenge for the scale-up production of gaseous hydrogen. Iron foam, which is composed of the second most abundant metal element on the earth, can boost the water splitting reactions after a simple treatment of surface phosphorization. The as-prepared electrocatalyst, which is denoted as FePx@Fe, exhibits an excellent activity in alkaline solutions, and requires overpotentials of 124 and 274 mV to approach 10 mA cm(-2) for hydrogen evolution reaction and oxygen evolution reaction, respectively. Meanwhile, FePx@Fe also shows a remarkable performance on overall water splitting, which only needs 1.67 V to reach 10 mA cm(-2) and exhibits a satisfying long-term durability. The fabrication strategy of surface phosphorization on iron foam to obtain FePx@Fe can be valuable for the application of non-noble-metal electrocatalysts toward water splitting.