Structural Design Induced Electronic Optimization in Single-Phase MoCoP Nanocrystal for Boosting Oxygen Reduction, Oxygen Evolution, and Hydrogen Evolution.

Abstract

Structural and compositional design of multifunctional materials is critical for electrocatalysis, but their rational modulation and effective synthesis remain a challenge. Herein, a controllable one-pot synthesis for construction of trifunctional sites and preparation of porous structures is adopted for synthesizing dispersed MoCoP sites on N, P codoped carbonized substance. This tunable synthetic strategy also endorses the exploration of the electrochemical activities of Mo (Co)-based unitary, Mo/Co-based dual and MoCo-based binary metallic sites. Eventually benefiting from the structural regulation, MoCoP-NPC shows excellent oxygen reduction abilities with a half-wave potential of 0.880V, and outstanding oxygen evolution and hydrogen evolution performance with an overpotential of 316mV and 91mV, respectively. MoCoP-NPC-based Zn-air battery achieves excellent cycle stability for 300h and a high open-circuit voltage of 1.50V. When assembled in a water-splitting device, MoCoP-NPC reaches 10mA cm-2 at 1.65V. Theoretical calculations demonstrate that the Co atom in the single-phase MoCoP has a low energy barrier for oxygen evolution reaction (OER) owing to the migration of Co 3d orbital toward the Fermi level. This work shows a simplified method for controllable preparation of prominent trifunctional catalysts.