Heterogeneous Ni‐Boride/Phosphide Anchored Amorphous B‐C Layer for Overall Water Electrocatalysis

Abstract The rational design of efficient and economical bifunctional electrocatalysts remained a challenge for overall water electrolysis. In this work, the Ni‐boride/ phosphide particles anchored amorphous B‐doped carbon layer with hierarchical porous characteristics in Ni foam (Ni 3 P/Ni 3 B/B−C/NF) was fabricated for overall water splitting. The Boroncarbide (B 4 C) power was filled and fixed in the NF interspace through the electroplating and electroless plating, and then annealed in vacuum high temperature. The amorphous B−C layer derived from the B4 C not only speeded up the electron transport, but also cooperate with Ni‐boride/phosphide to enhance the electrocatalytic activity for HER and OER synergistically. Furthermore, the hierarchical porous architecture of Ni 3 P/Ni 3 B/B−C/NF increased space utilization to load more active materials. The self‐supported Ni 3 P/Ni 3 B/B−C/NF electrode possessed a low overpotential of 212 and 280 mV to deliver 100 mA cm −2 for HER and OER, respectively, and high stability for 48 h. In particular, the electrolyzer constituted with the Ni 3 P/Ni 3 B/B−C/NF bifunctional electrocatalyst only required a voltage of 1.59 V at 50 mA cm −2 for water electrocatalysis under alkaline medium, and demonstrated long‐term stability for 48 h. This study provides a new technical path for the development of bifunctional of transition metal borides to promote the application of hydrogen production from water splitting.