Three‐dimensional transition metal phosphide heteronanorods for efficient overall water splitting

: Developing low-cost electrocatalysts with superior activity and durability for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) poses a huge challenge to water splitting. Herein, a simple and scalable strategy was proposed to fabricate three-dimensional (3D) heteronanorods on nickel foam, of which the nickel-molybdenum phosphide nanorods were covered with cobalt-iron phosphides (P-NM-CF HNRs). Based on the rational design, P-NM-CF HNRs exhibited large surface area, tightly connected interfaces, optimized electronic structures, and synergy between metal atoms. Accordingly, P-NM-CF HNRs exhibited prominently high catalytic activity to OER in alkali and wide-pH HER. For overall water splitting, the catalysts only requires a voltage of 1.53 V to reach the current densities of 10 mA•cm -2 in 1 M KOH with prominent stability, for which the activity was not degraded after stability test for 36 h. The novel strategy can inspire durable non-precious metal catalysts design for large-scale industrial water splitting.