Controlled Synthesis of 3D Flower‐like Ni 2 P Composed of Mesoporous Nanoplates for Overall Water Splitting

Developing efficient non‐noble metal and earth‐abundant electrocatalysts with tunable microstructures for overall water splitting is critical to promote clean energy technologies for a hydrogen economy. Herein, novel three‐dimensional (3D) flower‐like Ni 2 P composed of mesoporous nanoplates with controllable morphology and high surface area was prepared by a hydrothermal method and low‐temperature phosphidation as efficient electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Compared with the urchin‐like Ni x P y , the 3D flower‐like Ni 2 P with a diameter of 5 μm presented an efficient and stable catalytic performance in 0.5  m H 2 SO 4 , with a small Tafel slope of 79 mV dec −1 and an overpotential of about 240 mV at a current density of 10 mA cm −2 with a mass loading density of 0.283 mg cm −2 . In addition, the catalyst also exhibited a remarkable performance for the OER in 1.0  m KOH electrolyte, with an overpotential of 320 mV to reach a current density of 10 mA cm −2 and a small Tafel slope of 72 mV dec −1 . The excellent catalytic performance of the as‐prepared Ni 2 P may be ascribed to its novel 3D morphology with unique mesoporous structure.