Protein hydrogel networks: A unique approach to heteroatom self-doped hierarchically porous carbon structures as an efficient ORR electrocatalyst in both basic and acidic conditions

It is of great allure but still challenging to construct carbon-based metal free electrocatalysts to replace Pt-based ones for efficient ORR in both acidic and alkaline media. In this work, protein-hydrogel networks are demonstrated as a precursor for preparing N, S-codoped, hierarchically porous carbon (NSPC) materials with tunable pore structure. Of note, NSPC-0.2-900 possesses a high pore volume of 0.8552 cm(3) g(-1) and shows excellent ORR activity in both alkaline (E-onset, similar to 0.93 vs. RHE) and acidic (E-onset, similar to 0.89 V vs RHE) media. As a cathode catalyst for zinc-air batteries, NSPC exhibits higher power density and better long-term durability than Pt/C does. The work presents a great potential of using protein as a precursor for preparing heteroatom doped, hierarchically porous carbon materials for energy and environmental applications.