Nanosheet self-assembled NiCoP microflowers as efficient bifunctional catalysts (HER and OER) in alkaline medium

Developing greatly efficient and steady non-noble metal bifunctional electrocatalyst is of great significance for reducing the energy consumption. In this work, we found that the construction of hierarchical nanostructures was an effective strategy to improve the catalytic performance of bimetallic transition-metal phosphide (NiCoP). Herein, we successfully synthesized the Ni1.5Co1.5P catalyst with porous nanosheet self-assembled microflowers (MFs) structure by sequential solvothermal, annealing and phosphorization treatment, and then adjusted the morphology of the MFs by changing the Ni/Co molar ratio to optimize its electronic structure and increase the exposed active sites, thereby improving catalytic activity of the catalyst. Specifically, the Ni1.5Co1.5P/MFs only required overpotentials of 141 mV and 314 mV to reach a current density of 10 mA cm−2 toward HER and OER, respectively. Impressively, during the continuous 12 h chronoamperometry measurement, the Ni1.5Co1.5P/MFs displayed good durability. In conclusion, this study provided a feasible strategy to explore and prepare low-cost non-noble metal bifunctional electrocatalysts.