Rational Design of Covalent Organic Frameworks for Oxygen Electrocatalysis: Recent Advances and Mechanistic Insights

Due to the excessive consumption of fossil fuels and the increasingly severe global environment, the world urgently needs to develop new clean and renewable energy sources. However, these energy sources have intermittency and instability, so it is necessary to vigorously develop efficient and large-scale energy conversion and storage technologies such as fuel cells, water electrolyzers, and metal-air batteries based on the core reactions of oxygen evolution reaction and oxygen reduction reaction. Because of their excellent molecular designability and structural tunability, covalent organic frameworks (COFs) show great potential for applications in this field. In this review, we first classify COF-based electrocatalysts based on the nature of active sites. Subsequently, strategies including structural design and functional synthesis for improving performance of COF-based electrocatalysts in the field of oxygen catalysis are systematically reviewed. Importantly, mechanism discussion of the performance improvement is highlighted. Finally, we put forward prospects for the future research directions, challenges, and development opportunities in this field. This review aims to provide guidance for the development of high-performance COF-based electrocatalysts through critical analysis of existing research, revealing the correlation between material design and mechanism for performance improvement.