A gasification strategy to anchor Fe, Ni dual-sites on biomass-derived N, P co-doped porous carbon as an efficient bifunctional catalyst for Zn-air batteries

The fabrication of distinct sites on the carbonized substrate as bifunctional oxygen catalysts is pivotal for enhancing the practicality of Zn-air batteries, but remains a formidable challenge. Herein, a gas doping strategy is reported for anchoring Ni nanoparticles and further increasing FeNx sites on biomass-derived Fe, N, and P co-doped porous carbonized materials as highly efficient bifunctional electrocatalysts. The inherent porous structure and heteroatom of rattan tea provide a superior carrier for Fe and Ni-based active species. Notably, the as-prepared Ni@FeNPC/Fef shows unprecedented capability for oxygen reduction reaction and excellent catalytic activity for oxygen evolution reaction. In situ Raman spectroscopy studies shed light on the role of FeNx and heteroatom-doped carbon during the oxygen reduction reaction. Density functional theory calculations verify the catalytic mechanism on various active sites of Ni@FeNPC/Fef. Moreover, the Ni@FeNPC/Fef-based Zn-air battery maintains cyclic stability for over 400 h with negligible voltage degradation. This strategy endows a novel route for converting biomass into practical electrocatalysts for diverse energy-related systems.