Oriented Synthesis of Pyridinic‑N Dopant within the Highly Efficient Multifunction Carbon-Based Materials for Oxygen Transformation and Energy Storage
journal contributionposted on 08.07.2020, 17:14 by Fantao Kong, Yu Qiao, Chaoqi Zhang, Xiaohong Fan, Qingbiao Zhao, Aiguo Kong, Yongkui Shan
Developing highly active metal-free electrode materials via inexpensive and earth-abundant resources is of paramount importance for improving the energy-conversion and -storage efficiency and promoting the large scale development of renewable energy. Herein, the high density pyridinic-N doped graphene–nanotube complexes with hierarchical networks (denoted NGTB) are fabricated based on a facile and efficient two-step control synthetic strategy using urea as the nitrogen source and boric acid (H3BO3) as the splicing agent. These controls and manipulations can significantly enhance the connection between the few-layer graphene and carbon nanotubes and create abundant defects that affect the electronic structure of the carbon matrix and contribute to the oriented synthesis of the desired pyridinic-N species. The derived NGTB-900 displays the excellent performance for catalyzing oxygen reduction reaction (ORR) and energy storage. The liquid zinc–air battery (ZAB) using NGTB-900 as the cathode catalyst affords a higher open-circuit voltage (1.54 V), power density (149 mW cm–2), and specific capacity (873 mAh gZn–1), as well as excellent cycling stability over the noble-metal counterparts (Pt/C; Pt/C + IrO2). This work provides an effective strategy for taking advantage of the abundant and low-cost resources to construct the highly efficient multifunction carbon-based materials for promising the large scale development of the renewable energy conversion and storage technologies.