Hierarchical 2D sheets of N and S co-doped Fe-based electrocatalyst for efficient oxygen reduction in advanced Zn-air battery

Currently, the scientific community is keenly interested in the design and production of efficient and durable transition metal electrocatalysts for oxygen reduction reactions (ORR). Therefore, this study reports a simple and reproducible N and S co-doped two-dimensional (2D) hierarchical porous electrocatalyst is reported. NSC the support material first was obtained by pyrolyzing trithiocyanuric acid (TTCA) and loaded on hemin to obtain the final material named Fe/NSC-800. 2D hierarchical porous structures with the large specific surface area were constructed by using TTCA as the template, S source, and additional N source. The addition of hemin not only retained the morphology of the NSC but also provided source of Fe for Fe/NSC-800. The Fe/NSC-800 possessed the limiting current density of 5.85 mA cm-2 and good ORR stability in 0.1 M KOH solution. Based on the excellent ORR performance of Fe/NSC-800, it was assembled into the primary Zn-air battery, which also exhibited satisfactory open circuit voltage (1.55 V) and energy density (880 W h kg-1). This work has contributed to the rational engineering and fabrication of high-performance ORR electrocatalysts for Zn-air battery applications.