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

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.