CoFeS2@CoS2 Nanocubes Entangled with CNT for Efficient Bifunctional Performance for Oxygen Evolution and Oxygen Reduction Reactions

Exploring bifunctional electrocatalysts to lower the activation energy barriers for sluggish electrochemical reactions for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are of great importance in achieving lower energy consumption and higher conversion efficiency for future energy conversion and storage system. Despite the excellent performance of precious metal-based electrocatalysts for OER and ORR, their high cost and scarcity hamper their large-scale industrial application. As alternatives to precious metal-based electrocatalysts, the development of earth-abundant and efficient catalysts with excellent electrocatalytic performance in both the OER and the ORR is urgently required. Herein, we report a core-shell CoFeS2@CoS2 heterostructure entangled with carbon nanotubes as an efficient bifunctional electrocatalyst for both the OER and the ORR. The CoFeS2@CoS2 nanocubes entangled with carbon nanotubes show superior electrochemical performance for both the OER and the ORR: a potential of 1.5 V (vs. RHE) at a current density of 10 mA cm(-2) for the OER in alkaline medium and an onset potential of 0.976 V for the ORR. This work suggests a processing methodology for the development of the core-shell heterostructures with enhanced bifunctional performance for both the OER and the ORR.

Automated summary

Exploring bifunctional electrocatalysts for sluggish electrochemical reactions is crucial for achieving lower energy consumption and higher conversion efficiency in future energy conversion and storage systems. This study reports the development of a carbon nanotube-entangled core-shell CoFeS2@CoS2 heterostructure as an efficient bifunctional electrocatalyst for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). The electrochemical performance of the CoFeS2@CoS2 nanocubes entangled with carbon nanotubes shows excellent performance in both the OER and the ORR.