Template-assisted synthesis of iron-nitrogen co-doped carbon hollow nanospheres for efficient oxygen reduction reaction

Single atomic metal-N-C materials are the most promising candidates to replace platinum-group-metal (PGM) catalysts for the oxygen reduction reaction (ORR), and show a broad application prospect in long-life rechargeable Zn-air batteries. Iron-nitrogen co-doped carbon hollow nanospheres (Fe-N-C/HSs) were fabricated via the self-polymerization of dopamine coated on removable SiO2 nanospheres and spontaneous chelation of Fe3+ ions, followed by rational pyrolysis and template removal processes. Benefitted from unique micropores hollow structures and highly exposed Fe-Nx active sites, the relevant Fe-N-C/HSs exhibited satisfied oxygen reduction performance (e.g. half-wave potential: 0.87 V), endowing the Fe-N-C/HSs assembled Zinc-air battery delivering a high power density of 157 mW cm(-2) and large specific capacity of 805 mA h g(-1).