Cooperative non-covalent interactions-directed the supramolecular self-assembly and its derivative for bifunctional water electrocatalysis

Abstract

The highly dispersed transition metal phosphides have gradually become viable electrocatalysts candidates for water splitting due to their high efficiency, ease of availability, and good stability. Herein, a novel electrocatalyst composed of Co2P embedded in N and P co-doped carbon (Co2P @ NPC) was designed using a tuned self-assembly strategy and high-temperature calcination. The former strategy was employed to prepare a supramolecular precursor self-assembled via cooperative non-covalent interactions. Specifically, Co2+ ions were introduced into the preorganized phytic acid (PA)-melamine (MA) hydrogen-bonded system, and competitively substituted hydrogen atoms to form coordinate bonds with PA. The Co2P @ NPC catalyst synthesized from the 800 ℃-calcinated precursor exhibited a well-modulated structure of carbon-entrapping Co2P nanoparticles, which promoted its efficient bifunctional electrocatalysis for hydrogen and oxygen evolution reactions (HER and OER). To achieve a current density of 10 mA cm−2, the electrocatalyst only required overpotentials of 288 mV for HER and 476 mV for OER.