Ionothermal-Transformation Strategy to Synthesize Hierarchically Tubular Porous Single-Iron-Atom Catalysts for High-Performance Zinc-Air Batteries

Inexpensive carbon-based nitrogen-coordinated iron single-atom catalysts (CN-FeSACs) have been recently demonstrated as the most promising platinum substitutions for boosting the sluggish oxygen electrode performance in fuel cells and metalair batteries. However, it is still a great challenge to develop economical and effective CN-FeSACs satisfying the needs of high output power. Herein, an ionothermal-transformation strategy is proposed to synthesize hierarchically tubular porous CN-FeSACs with an ultrahigh special surface area of 2500 m(2) g(-1) to host abundant single-atom iron sites with an attempt to simultaneously boost sluggish oxygen reduction reaction (ORR) kinetics and mass transport. Benefiting from the unique feature, the final obtained material shows an ORR half-wave potential of 0.885 V, higher than that of benchmark Pt/C (0.850 V). When assembled into zinc-air battery, a large peak power density of 208 mW cm(-2) is achieved, which is far superior to that of Pt/C (119 mW cm(-2)). This work provides an economical and feasible strategy to prepare hierarchically porous CN-FeSACs for energy conversion.

Automated summary

An ionothermal-transformation strategy was proposed to synthesize hierarchically tubular porous CN-FeSACs with ultrahigh special surface area, hosting abundant single-atom iron sites to simultaneously boost ORR kinetics and mass transport. The final material showed higher ORR half-wave potential and peak power density in zinc-air battery compared to benchmark Pt/C, providing an economical and feasible strategy for energy conversion.