Iron phosphides nanoparticles strongly coupled to N-doped carbon for high-efficiency oxygen reduction and evolution

In this study, we first reported a simple method for preparing an iron phosphide bifunctional oxygen catalyst by combining nitrogen-doped carbon. The d-band center of the catalytic material and the free energy of the intermediate were optimized with a half-wave potential of 0.87 V and an overpotential of 0.39 V at 10 mA·cm−2 in 0.1 M KOH, which was comparable to the catalytic activity of the precious metal-based catalyst. [Display omitted] •Construction of N-doped carbon-loaded Fe2P nanoparticle composite structures.•DFT calculations show that the center of the d-band of Fe2P/NC is shifted downwards.•The Fe2P/NC catalyst has a low potential gap ΔE (ΔE = Ej=10 − E1/2) of about 0.75 V.•Zinc-air battery with a specific capacity of 833 mAh·gZn-1 and a cycle performance of up to 1320 cycles. Constructing composite structures is an effective strategy for tailoring the electronic configuration and balances the adsorption/desorption capability of oxygen-containing intermediates for obtaining high-performance bifunctional catalysts. Herein, an in-situ pyrolysis strategy was used to construct Fe2P nanoparticles supported on N-doped carbon (Fe2P/NC) catalyst. The DFT indicated that the catalytic activity of the as-prepared catalyst is significantly increased by the strong electronic interaction between the Fe2P nanoparticles and the nitrogen-doped carbon, which endows the catalyst with fast electron transfer capability and optimizes the free energy between the catalyst and the adsorbed intermediate, as well as the d-band center of the material. The as-synthesized Fe2P/NC has a low potential gap ΔE (ΔE = Ej=10 – E1/2) of ca. 0.75 V, a specific capacity as high as 833 mAh·gZn−1 and cycling stability for 1320 cycles at the current density of 10 mA·cm−2. Such a synthesis strategy provides an effective route to realizing applications for portable electronic Zn-air battery-related devices.