Volatile guest molecule mediated strategy to convert covalent organic framework into nitrogen, sulfur-doped carbon as metal-free oxygen reduction electrocatalysts

Sihang Qiu; Shuanglong Lu; Hongyin Hu; Shaoda Huang; Fang Duan; Han Zhu; Qiang Fu; Chengxi Fu; Mingliang Du

doi:10.1016/j.jcis.2023.11.154

Volatile guest molecule mediated strategy to convert covalent organic framework into nitrogen, sulfur-doped carbon as metal-free oxygen reduction electrocatalysts

J Colloid Interface Sci. 2024 Mar:657:114-123. doi: 10.1016/j.jcis.2023.11.154. Epub 2023 Nov 25.

Authors

Sihang Qiu¹, Shuanglong Lu², Hongyin Hu¹, Shaoda Huang¹, Fang Duan¹, Han Zhu¹, Qiang Fu³, Chengxi Fu⁴, Mingliang Du⁵

Affiliations

¹ Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China.
² Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: lushuanglong@jiangnan.edu.cn.
³ Guangdong Key Laboratory of Electric Power Equipment Reliability, Electric Power Research Institute of Guangdong Power Grid Co., Ltd., Guangzhou, Guangdong, China.
⁴ School of Energy and Environment, City University of Hong Kong, Hong Kong, China.
⁵ Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: du@jiangnan.edu.cn.

PMID: 38035414
DOI: 10.1016/j.jcis.2023.11.154

Abstract

Covalent organic framework (COF) derived metal-free carbon materials have emerged as promising electrocatalysts for the oxygen reduction reaction (ORR). Herein, a volatile guest molecule mediated-pyrolysis strategy was explored on a designed thiophene-rich and imine-linked COF. Through the modulation of guest mediators (iodine and sulfur), the properties of the as-obtained carbon materials can be well regulated. The optimized nitrogen and sulfur dual-doped carbon electrocatalyst demonstrates remarkable ORR activity with a half-wave potential of 0.87 V and impressive durability, with only an 8% current loss over 21 h. The corresponding assembled zinc-air battery has a comparable power density (60 mW cm^-2) to that of the commercial Pt/C. It is proposed that the coexistence of the guest mediators iodine and sulfur in the channels of COFs could prevent the loss of N species. The enhanced N content and N/S ratio are assumed to be responsible for the ORR performance. This study puts forward a novel strategy to prepare COF-derived carbon materials mediated by volatile guest molecules, which may provide new insights into the development of metal-free ORR catalysts.

Keywords: Covalent organic framework; Guest molecule; Heteroatom doping; Metal-free electrocatalyst; Oxygen reduction reaction.