FeP nanoparticles highly dispersed on N,P-doped petaloid carbon nanosheet: Interface engineering and boosted intrinsic ORR activity

Abstract

Modulating the surface structure and intrinsic activity of iron phosphides (FeP) is of great importance to improve their oxygen reduction reaction (ORR) activity. In this work, aminotrimethylene phosphonic acid (ATMP) and melamine (MA) were introduced as acid and base ligand respectively to fabricate hydrogen-bonded organic frameworks (HOF)-like precursor (ATMP-MA). After high-temperature treatment, the obtained FeP supported on 3D nitrogen (N) and phosphorus (P)-doped petaloid carbon nanosheet (FeP/NPC) displayed the desired improved ORR performance. An improved onset potential (0.922 V vs. RHE) and diffusion limiting current (5.480 mA cm−2) could be realized, superior to those of Pt/C (0.911 V, 5.380 mA cm−2). Moreover, ultraviolet photoemission spectroscopycharacterization consistently revealed that the proper P and N doping could effectively regulate the electronic structure, promote electron transport, and lower the d-band center position of Fe. This work may streamline the strategy of transition metal phosphides with enhanced reactive activity for ORR.