Silver Nanoparticles Embedded in COFs as Reusable Photocatalyst for Oxidative Coupling of Benzylic Amine and Carboxylation of Benzyl Alcohol Derivatives

In the present study, we have synthesized a benzothiadiazole derivative-based 2D donor–acceptor BtCOF, which we then customized by incorporating AgNPs over the COF, denoted as Ag/BtCOF. The AgNP-embedded BtCOF catalyst was characterized by various techniques like IR, XRD, SEM, TEM, XPS, UV–vis, photoluminescence (PL), electrochemical impedance spectroscopy (EIS), transient photocurrent response (TPR), and time resolved fluorescence (TRF) analysis. The activity of the catalyst was studied for the visible-light-assisted oxidative coupling of benzylic amines and the photocatalytic carboxylation of benzyl alcohol derivatives. Herein, the COF served as a support for the metal particles as well as provided a synergistic impact that improved the yield of the product formed during the catalytic process. The incorporation of AgNPs significantly enhances charge separation and promotes efficient electron transfer, while the intrinsic narrow band gap of BtCOF facilitates superior light absorption and increases the photocatalytic productivity. This strategic modification enhanced photophysical properties and has led to extraordinary photocatalytic activity in photocatalytic oxidization of benzylamine derivatives (conversion and selectivity ≥90%) in 4 h and carboxylation of C(sp 3 )-O bonds of benzyl alcohols (conversion ≥78% and selectivity ≥92%) in 24 h. Furthermore, the catalyst demonstrated excellent recyclability over several cycles without losing its catalytic activity.