Co/Co–N/Co-O Rooted on rGO Hybrid BCN Nanotube Arrays as Efficient Oxygen Electrocatalyst for Zn–Air Batteries
Lei Cao, Yu Wang, Qian Zhu, Lanlan Fan, Yu Wu, Zhenhuan Li, Shixian Xiong, Feng Gu
Abstract
Developing high-performance non-noble metal bifunctional oxygen reduction and evolution reaction electrocatalysts is a critical factor for the commercialization of rechargeable Zn–air batteries. Herein, Co/Co–N/Co–O rooted on reduced graphene oxide (rGO) hybrid boron and nitrogen codoped carbon (BCN) nanotube arrays (BCN/rGO-Co) is prepared by facile low-temperature precross-linking and high-temperature pyrolysis treatment. Benefit from the synergistic effect of its B/N codoping, Co/Co–N/Co–O bifunctional active sites, 3D hybrid porous structure of BCN nanotubes, and highly conductive rGO sheets. The obtained BCN/rGO-Co exhibits superior bifunctional oxygen catalytic activity with a positive ORR half-wave potential (0.85 V) and a low OER potential (1.61 V) at 10 mA cm–2. Additionally, the BCN/rGO-Co-based liquid Zn–air batteries displays a large peak power density of 157 mW cm–2, and a long charge/discharge cycle stability of 200 h, outdoing the commercial Pt/C+Ru/C catalyst.