Engineering Strategy for Enhancing the Co Loading of Co-N₄-C Single-Atomic Catalysts Based on the ZIF-67@Yeast Construction

The Co-N-4-C single-atom catalysts(SACs)have attracted great research interest in the energy storage and conversionfields owing to 100% atom utilization. However, enhancing the Co loadingfor higher electrocatalytic performance is still challenging. In thiscontext, we propose an engineering strategy to fabricate the highCo atomic loading Co-N-4-C SACs based on thezeolitic imidazolate framework-67 (ZIF-67)@yeast construction. Therich amino groups provide the possibility for Co2+ ionanchorage and ZIF-67@yeast construction via the biomineralizationof yeast cells. The functional design induces the formation of Co-N-4-C sites and regulates the porosity for exposure ofsuch Co-N-4-C sites. As a result, the Co-N-4-C sites were anchored on spherical micrometer flowercarbonaceous materials through our novel strategy. The as-obtainedoptimal sample exhibited a Co atomic loading of 12.18 wt % and a specificsurface area of 403.26 m(2) g(-1). High Coatomic loading and large specific surface area delivered excellentelectrocatalytic kinetics as well as a high discharge voltage of 1.08V at 10 mA cm(-2) for more than 100 h in Zn-airbatteries. This work represents a promising strategy for fabricatinghigh-loading SACs with high activity and good durability.