Tailoring the structural properties of COFs-based electrocatalysts through molecular design and functionalization and their characterization for oxygen reduction reaction

The sluggishness of the Oxygen reduction reaction (ORR), alongside the scarcity and high cost of the currently used platinum-based electrocatalysts have made carbon-based electrocatalysts gain more recognition in ORR applications. Covalent organic frameworks (COFs) have recently gained great interest from researchers and material scientists for oxygen electroreduction. COFs are a new class of emerging crystalline polymers having a highly porous structure constructed by organic molecules through covalent linkages. Owing to their many interesting features such as their large surface area and adjustable porosity resulting from covalent bonds, they have found great applicability in research. The adjustable features of the COFs make them desirable and appropriate for the next generation of electrocatalysts in the field of energy. This review summarizes design strategies for tuning the properties of COF for ORR applications. This includes new structural design, modification with organic and inorganic molecules, metal doping and pyrolysis. It further discusses both experimental and theoretical techniques for properties changes analysis within these molecules, including structural backbone changes, porosity, electronic states and active sites evolution by COFs modification and how these changes relate to the ORR electrocatalysis efficiency. Furthermore, this review provides design and construction prospectives for researchers in designing new COF-based electrocatalysts for ORR. This review aims to analyze electrocatalysts design and modification and elucidate their structure–property relationship in ORR. • Significance of molecular design of COFs in oxygen electrocatalysis. • Chemical environments affect the active sites efficiency. • Enhancing electrocatalysis through different functionalities. • Coupling experimental and computational techniques for active sites elucidation.