CeO_(2)C_(2)Nanoparticles with Oxygen-Enriched Vacancies In-site Self-embedded in Fe,N Co-doped Carbon Nanofibers as Efficient Oxygen Reduction Catalyst for Zn-Air Battery

Rational design of robust non-noble electrocatalysts with numerous oxygen vacancies and highly reactive activity for oxygen reduction reaction(ORR)towards Zn-air batteries is extremely paramount yet challenging.Herein,a novel CeO_(2)C_(2)nanoparticles self-embedded in Fe,N co-doped carbon nanofibers(CeO_(2)C_(2)@Fe-N-C)heterostructure catalyst has been prepared by the in-site dual template assisted electrospinning technique and subsequent high temperature pyrolysis strategy.Thanks to the CeO_(2)C_(2)with oxygen-enriched vacancies and versatile Fe-N-C with rich reactive species and high conductivity,CeO_(2)C_(2)@Fe-N-C catalyst exhibits outstanding catalytic performance in the ORR process,and shows excellent methanol tolerance and cycle stability.In addition,CeO_(2)C_(2)@Fe-N-C delivers a nearly four-electron transfer process in the process of oxygen reduction catalysis,providing a fast-electrochemical kinetic rate,which makes it an efficient air cathode for the Zn-air battery.Importantly,the Zn-air battery fabricated with CeO_(2)C_(2)@Fe-N-C cathode achieves superior performance including large open-circuit voltage(1.5 V)and high specific capacity(780 mAh·g–1 at 10 mA·cm–2)together with superior reversibility and cycling stability,outperforming commercial Pt/C catalyst.The present work introduces a new strategy to design and develop highly active non-noble catalysts and highlights the synergy from heterostructure in oxygen electrocatalysis for advanced Zn-air batteries.