Multifunctional Disordered Sulfur-Doped Carbon for Efficient Sodium-Ion-Exchange and 2-Electron-Transfer-Dominant Oxygen Reduction Reaction
Hanvin Kim, Hyeon-Su Yang, Jun Kang, Nozomi Takeuchi
Abstract
Multifunctional disordered sulfur-doped carbon catalyst is demonstrated for use in both sodium-ion-exchange and the 2-electron-transfer-dominant oxygen reduction reaction (ORR) for energy storage and conversion applications. The disordered sulfur-doped carbon prepared via a simple plasma-in-liquid approach showed distinct performance for each electrochemical application, and the underlying fundamental mechanisms were experimentally demonstrated. Benefiting from the enhanced reaction kinetics derived from C–S covalent bonds, superior sodium-ion-exchange performance with a high reversible capacity of ∼150 mA h g−1 over 5000 cycles is achieved with a stable rate capability. In addition, an efficient 2-electron-transfer-dominant ORR with a high current density of ∼25.66 mA cm−2 at a low overpotential of ∼0.890 V (vs. RHE) is obtained. This work cautiously proposes the importance of sulfur bonded to carbon to boost its electrochemical performance and is expected to provide new perspectives for various interdisciplinary applications.