Rationally design and modulation strategies of cobalt-based covalent organic frameworks (COFs) electrocatalysts towards energy conversion applications

Widespread interest has been shown in the design of effective, affordable and ecologically benign electrocatalysts for energy conversion applications. To resolve the growing energy demand, several types of new electrocatalysts have been designed in recent decades. In particular, covalent organic frameworks (COFs) have been emerged as a potential candidate for electrocatalysis due to their porous and crystalline structure, intrinsic ability to coordinate metal ions or host metal nanoparticles (NPs). Polygonal lattices with distinct topology and integrated discrete micropores and/or mesopores could be constructed by incorporating organic building blocks into durable, regularly organized two- and three-dimensional polymers as molecular scaffolding. Pre-planning, selection and modification of both the basic building units as well as the framework provide a multitude of structures with diverse, designable properties useful in electrocatalysis. With the rapid advancements in designing and developing highly efficient COF catalysts, particularly transition metal (TM)-incorporated materials, significant progress has been made in facilitating the nitrogen reduction reaction (NRR), the hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and carbon dioxide reduction reaction (CO₂RR). In addition, cobalt incorporated COFs (Co-COFs) have been considered as promising candidate for electrocatalytic applications owing to their tuneable architectures, high surface area, and exceptional catalytic activity. Long-term electrocatalytic performance may be impeded by the low chemical and thermal stability of Co-COFs. Furthermore, scaling problems for practical applications arise from the expense and complexity of their synthesis. Moreover, more research is necessary to fully comprehend their structure-performance correlations. Herein, we highlight current advancements in design principles, effective strategies of synthesis and structural modifications of cobalt-incorporated COFs. Furthermore, we compare and discuss key examples of Co-COFs and their performance towards selected energy conversion applications. Finally, remaining challenges and future perspectives for designing and developing high performance electrocatalysts have been provided for diverse energy conversion applications.