Three‐Dimensional Transition Metal Phosphide Heteronanorods for Efficient Overall Water Splitting

Abstract The development of low‐cost electrocatalysts with excellent activity and durability for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) poses a huge challenge in water splitting. In this study, a simple and scalable strategy is proposed to fabricate 3 D heteronanorods on nickel foam, in which nickel molybdenum phosphide nanorods are covered with cobalt iron phosphide (P‐NM‐CF HNRs). As a result of the rational design, the P‐NM‐CF HNRs have a large surface area, tightly connected interfaces, optimized electronic structures, and synergy between the metal atoms. Accordingly, the P‐NM‐CF HNRs exhibit a remarkably high catalytic activity for the OER under alkaline conditions and wide‐pH HER. For overall water splitting, the catalyst only requires a voltage of 1.53 V to reach a current density of 10 mA cm−2 in 1 m KOH with prominent stability, and the activity is not degraded after stability testing for 36 h. This new strategy can inspire the design of durable nonprecious‐metal catalysts for large‐scale industrial water splitting.