Collaborative integration of Fe-Nx active center into defective sulfur/selenium-doped carbon for efficient oxygen electrocatalysts in liquid and flexible Zn-air batteries

Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction reactions. However, the controllable multi-active site design is a highly intricate topic for catalyst synthesis. Employing pre-trapping and post-activation strategy, Fe-N bonding structure and S, Se functionalized heteroatom are integrated into a conductive porous carbon. In this process, the nitrogen-abundant polymer 1,3,5-triformylbenzene-tris(4-aminophenyl)benzene (Tf-TAPA) adsorbs Fe3 + under the intrinsically metal anchoring ability of N atoms and simultaneously in-situ assembles longchain thiophene-S. Subsequently, the Fe3 + is transformed into Fe-Nx moieties with the conversion of the organic chain to incompletely graphitized carbon. Furthermore, the alteration of the electronic configuration achieved through the introduction of dual-atom S and Se leads to a pronounced enhancement in catalytic efficiency. Benefitting from the Fe-Nx bonding structure, dense structural defects, and conductive carbon networks, the resultant Fe-S,Se/NCNs possesses a positive half-wave potential of 0.86 V and a 90% current retention rate, outstripping the Pt/C benchmark. Moreover, the liquid and flexible ZAB driven by Fe-S,Se/NCNs achieves large power densities of 259.7 and 164.7 mW/cm2 , respectively. This study provides a new comprehension in developing an efficient and stable M-N-C oxygen electrocatalyst. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.