This research demonstrates that Ag₃PO₄ efficiently catalyzes intramolecular and intermolecular [2+2] and Diels-Alder cycloadditions under visible-light irradiation. The additive-free, catalyst-recyclable approach generates long-lived radical cations (lifetime >2ms) through visible light excitation of Ag₃PO₄, oxidizing aromatic alkene adsorbates. The stability of these radical cations is attributed to the low reduction power of conduction band electrons and strong electrostatic interaction with the particle surfaces. This work highlights the potential of inorganic semiconductors for sunlight-driven radical cation-mediated synthesis.
