Alkali‐driven Assembly of Protein‐rich Biomass Boosts the Electrocatalytic Activity of the Derived Carbon Materials for Oxygen Reduction

Though of great significance, it is still a challenge to facilely engineer biomass into heteroatom-doped porous carbon materials (HPCs)-based electrocatalysts with high activity and durability to replace Pt-based ones for oxygen reduction reaction (ORR). Herein, alkali-driven assembly strategy is proposed to boost the ORR catalytic performance of the HPCs derived from protein-rich biomass. Egg white for instance, can self-assemble into a hydrogel with 3D networks in the presence of alkali. The formed hydrogel can work as a self-heteroatom (N, S) doped and self-activated precursor for fabricating HPCs. The as-obtained NSPC-1-900 ORR catalyst has onset potential (E-onset) and half-wave potential (E-1/2) values of 1.03 and 0.88V (vs. RHE) respectively, and it represents an air electrode catalyst for Zn-air batteries with high power density and durability. This work affords a facile and effective strategy of utilizing low-cost, abundant and sustainable biomass to prepare HPCs for energy storage and conversion.