Two-dimensional covalent organic frameworks for electrocatalysis: Achievements, challenges, and opportunities

Covalent organic frameworks (COFs) represent an emerging class of crystalline porous polymers with high porosity, good stability, and adjustable structure, and their excellent characteristics lay a solid foundation for electrocatalysis. This review systematically introduces the design principles of the catalytic sites in two-dimensional (2D) COF-based electrocatalysts and analyzes the relationship between 2D COF structure and their electrocatalytic performances. In particular, the recent progress in the field of 2D COFs as electrocatalysts is comprehensively summarized. Finally, we discuss the current shortcomings and challenges on tailoring 2D COF for high-performance electrocatalysts in details, and look forward to promoting more researches on 2D COF-based electrocatalysts.