Bottom-Up Synthesis of Nitrogen-Doped Graphynes for High-Performance Electrocatalysis in a Zn-Air Battery
Mengyang Wang, Caimei Yu, Haotian Sun, Hongxu Liu, Shijie Ren
Abstract
Nitrogen-doped carbon materials have been developing rapidly over the past decade as ideal metal-free electrocatalysts in the oxygen reduction reaction (ORR). Nevertheless, several challenges persist in the postdoping methods, including the uneven distribution of active sites and low nitrogen contents, disturbing the electrocatalytic performances of the obtained materials. In this study, we present a simple and straightforward approach for the in situ synthesis of graphyne-based catalysts via Sonogashira reaction of nitrogen-rich acetylene- and halogene-substituted heterocyclic arenes followed by heat treatment. The obtained catalyst TBGY-800 demonstrates a more positive onset potential and half-wave potential in ORR tests compared to other counterparts owing to its higher nitrogen-doping content and specific surface area. When applied as the cathode material in an actual zinc-air battery, TBGY-800 exhibits remarkable power density (138.6 mW cm –2 ) and specific capacity (636.6 mAh g –1 ). This work brings new insight for the rational design of nitrogen-rich carbon materials for electrocatalytic applications.