A photosensitive conjugated pyromellitic-based covalent organic framework composite for visible-light-driven NADPH cofactor regeneration and aerobic oxidation in green photocatalytic applications

Abstract

Harnessing solar energy for sustainable chemical transformations is an exciting frontier in green chemistry. In this study, we are thrilled to share that the design and synthesis of pyromellitic-based covalent organic framework composite photocatalyst (PGCOF composite) were achieved by cleverly linking pyromellitic dianhydride (P) and triaminoguanidinium chloride (G) photochromic moieties. The PGCOF composite photocatalyst shows remarkable solar light absorption, high molar extinction coefficients, and excellent charge separation properties, as confirmed by UV-visible spectroscopy, chronopotentiometry, and electrochemical impedance spectroscopy. Owing to these attributes, the PGCOF composite displays remarkable photocatalytic activity, delivering an NADPH regeneration yield of 82.9%, far surpassing the individual P and G components. Furthermore, the PGCOF composite efficiently catalyzes the solar-driven aerobic oxidation of toluene to benzoic acid with a yield of 93.9%, underscoring its promising potential for value-added chemical synthesis. An effective strategy for developing next-generation photocatalysts involves integrating π-conjugated donor–acceptor architectures with photochromic units in a covalent organic framework (COF) composite. Nonetheless, achieving efficient dual functionality, such as NADP⁺ reduction and aerobic oxidation, continues to demand innovative molecular design.