Sulfurated Metal–Organic Framework-Derived Nanocomposites for Efficient Bifunctional Oxygen Electrocatalysis and Rechargeable Zn–Air Battery
Zexing Wu, Hengbo Wu, Tengfei Niu, Shuai Wang, Gengtao Fu, Wei Jin, Tianyi Ma
Abstract
The development and rational design of highly efficient and Earth-abundant bifunctional nanomaterials for electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) act as pivotal roles for the practical applications of rechargeable metal–air batteries. In this article, a Ni–Co-derived metal–organic framework (Ni–Co–MOF) is rapidly formed at ambient temperature, followed by a low-temperature sulfuration process to obtain Ni–Co-based sulfides couple with a nitrogen (N) and sulfur (S)-codoped carbon support with a porous structure (Ni–Co–S/NSC). The designed Ni–Co–S/NSC presents excellent electrocatalytic performances for OER (10 mA cm–2 @309 mV) and ORR (0.81 V @ E1/2) and a small ΔE (ΔE = Ej10 – E1/2) of 0.73 V in an alkaline electrolyte, enabling its use as an outstanding cathode in rechargeable Zn–air batteries. In situ Raman spectra demonstrated that metal hydroxides formed during OER endowed the obtained electrocatalyst with a predominant catalytic performance. Impressively, a homemade rechargeable Zn–air battery composed by this nanocomposite as the cathode delivered remarkable properties with a peak power density of 137 mW cm–2 and a high specific capacity of 829 mAh g–1. The battery also demonstrated outstanding long-term stability with a well-maintained porous structure and crystal structure.