Emerging breakthroughs in covalent triazine frameworks: From fundamentals towards photocatalytic water splitting and challenges

Covalent triazine frameworks (CTFs) are an innovative type of porous organic material (POP) that has distinctive features, such as an aromatic CN linkages (triazine unit) with the lack of any sort of weaker bonding. Specifically, the strong aromatic covalent bond provide CTFs with a substantial degree of chemical stability and a significant amount of nitrogen, making them valuable for several functional purposes and the fascinating heteroatoms impact. CTFs are exhibiting favorable attributes including synthesis variety, stability, non-toxic, simple organic composition, and improved organized structure. CTFs possess distinct characteristics which render them very suitable for a variety of functions, such as gas purification and retention, energy conservation, photocatalysis, and heterogeneous catalytic processes. According to existing research, CTFs may be categorized into two types: amorphous and crystalline CTFs. After 2008, many synthesis technique have been proposed, including an ionothermal trimerization approach, an approach mediated by phosphorus pentoxide (P₂O₅) techniques that utilize amidine polycondensation, a technique mediated by super acids, and a technique based on Friedel-Crafts reactions. This review intends to provide a concise overview of the latest advancements in CTFs, including innovative synthesis techniques, geometries, properties, morphologies, functionalization and key parameters which significantly affect their photocatalytic performance. This review demonstrates several approaches for optimizing the morphological band structure, separation of charge particles, and transmission using distinct chemical and physical engineering techniques. The focus has been on improving and optimizing the efficiency of certain applications, such as photocatalytic hydrogen evolution, photocatalytic oxygen evolution, and photocatalytic overall water splitting. This study illustrates the complexity of the processes behind these photocatalytic reactions, providing valuable knowledge to address existing obstacles and pave the way for future advancements.