Co₂P/CoP embedded in N, P, S triply-doped hollow carbon towards enhanced oxygen electrocatalysis

Simultaneously dispersing phosphide crystallites and multiple heteroatoms in hollow carbon is a significant yet challenging task for achieving high-performance oxygen electrocatalysts of zinc-air batteries. Herein, a simple wrapping-pyrolysis strategy is proposed to prepare Co₂P/CoP embedded in N, P, S triply-doped hollow carbon (Co₂P/CoP@NPS-HC). Co₂P/CoP@NPS-HC composite features hollow polyhedral structure populated with numerous catalytically active Co₂P/CoP nanoparticles and N, P, S heteroatoms. This optimized catalyst exhibits excellent activity for oxygen reduction reaction, with a half-wave potential of 0.82 V vs. RHE, and impressive enhancement for oxygen evolution reaction, indicated by an overpotential of 400 mV at 10 mA cm^-2. Moreover, Co₂P/CoP@NPS-HC catalyst exhibits greater durability and superior methanol tolerance compared to commercial Pt/C. The excellent bifunctional electrocatalytic performance of Co₂P/CoP@NPS-HC catalyst is attributed to the synergistic effect of uniformly dispersed Co₂P/CoP nanoparticles and N, P, S triply-doped hollow carbon structure. The former provides abundant catalytically active sites, while the latter offers a high accessible specific surface area, as well as enhances catalytic activity and electronic conductivity due to its altered charge distribution.