The Construction of Hydrangea-like Vanadium-Doped Iron Nickel Phosphide as an Enhanced Bifunctional Electrocatalyst for Overall Water Splitting

The morphology and electronic structure dual modulation is an effective strategy to optimize the performance of the electrocatalysts. Herein, a hydrangea-like vanadium-doped FeNi2P hybrid material loaded on nickel foam (V-FeNi2P/NF) is constructed by a facile hydrothermal reaction followed by phosphorization for the first time. The introduction of foreign V effectively modulates the electronic structure of Ni and leads to hydrangea-like morphology. The optimized V-FeNi2P/NF with open-ended sites shows large electrochemically active surface area. Not surprisingly, the V-FeNi2P/NF displays remarkable electrocatalytic performances for both hydrogen evolution (HER) and oxygen evolution (OER) reactions in 1.0 M KOH solution, with reduced overpotentials of 70 and 200 mV to achieve a current density of 10 mA cm–2 for HER and OER, respectively. The assembled water electrolyzer using V-FeNi2P/NF as the anode and cathode electrodes only needs a low cell voltage of 1.57 V to deliver 10 mA cm–2 and shows excellent long-term stability and recoverability.