Interfacial dehalogenation-enabled hollow N-doped carbon network as bifunctional catalysts for rechargeable Zn-air battery

Abstract

Promoting oxygen reduction and evolution reactions using effective catalysts hold broad significance for clean energy utilization. In this work, hollow N-doped carbon networks (N-CNs) were fabricated via interfacial dehalogenation of polyvinyl dichloride (PVDC) on 2D CoAl-layered double hydroxide (LDH) with the presence of N source and used as efficient bifunctional catalysts. BET results revealed that as-made N-CNs had very large specific surface area (SSA, 550.4m2g−1 for 900°C-annealed N-CN (N-CN9)) and abundant pore hierarchy. Additionally, interconnected graphitic carbon walls, forming separated cells, can ensure high electrical conductivity, which were formed after acid-leaching of metallic components. Remarkably, N-CN9 showed excellent bifunctional activities towards oxygen reduction and evolution reactions. Moreover, N-CN9 assembled Zn-air battery (ZAB) exhibited an operating voltage of 1.35V under applied current density of 1.0mAcm−2, which is highly comparable to that of PtRu/C catalyst. Moreover, due to the pore hierarchy and large SSA, N-CN9-ZAB possessed much better rate capability and cycling stability than that of PtRu/C-ZAB.