Programming Covalent Organic Frameworks for Photocatalysis: Investigation of Synthesis Methods

Covalent organic frameworks (COFs) are crystalline, porous materials with exceptional potential as high-performance photocatalysts for applications such as hydrogen and hydrogen peroxide production. In this study, we systematically evaluates various synthesis methods to optimize the preparation of COFs, specifically targeting enhanced photocatalytic activity. Four different synthetic strategies including solvothermal synthesis, microwave synthesis, ultrasonic synthesis, and mechanochemical synthesis were explored to prepare TAPT-COF with identical molecular structures. Although all methods produced COFs with comparable crystallinity, porosity, and light absorption capacity, their photocatalytic efficiencies in hydrogen and hydrogen peroxide production varied significantly. Notably, the mechanochemical method, which involves ball milling to disrupt interlayer interactions and produce COF nanosheets, exhibited the highest photocatalytic performance, particularly in the COF-BM-30 min sample. This difference highlights the importance of morphology in photocatalytic activity. Our findings shed light on the impact of synthesis methods on COF properties and provide valuable guidance for molecular strategy development and industrial applications in photocatalysis.