Phase transition of phosphide induced by a novel quenching N-doping strategy for optimizing overall water splitting kinetics

Developing a simple and effective strategy to optimize the structure of phosphide to stimulate its industrial-scale current density for water decomposition is a great challenge. In this work, the ‘phosphorization-quenching ammonia treatment’ strategy was innovatively proposed to prompt N-doping and the phase transition of phosphide, thereby constructing the unique N-FeNiP/NF-T electrode. As anticipated, the well-designed N-FeNiP/NF-T obtained an industrial current density of 1 A cm −2 at only 282 mV for HER and 307 mV for OER, which is 0.90-fold of Pt/C and 0.52-fold of RuO 2 , respectively. Notably, the density functional theory calculation revealed that the N dopants further optimized the reaction kinetics of the N-Ni 2 P/NiP 2 heterostructure with high OER activity and the N-NiP 2 phase with high HER activity, leading to the maximization of the synergistic effect. Overall, this work provides a novel strategy to induce phase transition to construct efficient heterostructure electrodes with optimal reaction kinetics.