Electronic structure engineering of NiMoP phosphides toward highly active bifunctional electrocatalysis for alkaline water splitting

The rapid development of nanocatalysts promotes the progress of electrocatalysis. Designing high-efficiency electrocatalysts for energy conversion has become a mainstream research hotspot. In this work, hydrothermal method and tube furnace calcination were adopted to synthesize catalysts. The purpose is to enhance the hydrogen evolution reaction (HER) efficiency in alkaline media. Compared with conventional Ni-based catalysts, the introduction of Mo and P produces a synergistic electronic effect. It greatly optimizes the reaction kinetics of HER. The as-prepared NiMoP catalyst delivers an overpotential of 95.7 mV at −10 mA cm −2 . Its overpotential reaches 218 mV at −100 mA cm −2 . This performance is superior to Ni 2 P (η10 = 130.7 mV) and NiMo-LDH (η10 = 131.7 mV). Electronic interaction induced by phosphorization regulates the adsorption energy of HER intermediates. It also accelerates the reaction kinetics. These advantages are reflected in the reduced Tafel slope, lowered charge transfer resistance and decreased apparent activation energy. The obtained NiMoP exhibits outstanding oxygen evolution reaction (OER) activity under alkaline conditions. It only requires an overpotential of 193 mV to achieve 10 mA cm −2 OER current density in 1 M KOH. Meanwhile, it presents excellent long-term durability. The high OER activity originates from the increased number of electrochemical active sites. It also benefits from the improvement of intrinsic catalytic activity. More importantly, the synthetic route reported in this work shows good scalability. It provides a valuable strategy for the rational design of high-activity electrocatalysts.