Pyrene-Based Multicomponent Metallacages for Highly Efficient Adsorption and Photocatalytic Degradation of Perfluorooctanoic Acid.

Abstract

The remediation of perfluorooctanoic acid (PFOA) remains a critical challenge due to its exceptional chemical stability and bioaccumulation risks. Here, we present two pyrene-based multicomponent metallacages that synergistically integrate high-capacity adsorption and photocatalytic degradation of PFOA. The 4,4'-bipyridine tetracarboxylate-derived metallacage demonstrates a high PFOA adsorption capacity of 1223 mg/g, facilitated by multivalent electrostatic interactions and hydrogen bonds. Subsequent photocatalytic treatment of the preconcentrated PFOA achieves 91% defluorination within 6 h through a superoxide radical-mediated chain-shortening mechanism, as verified by electron paramagnetic resonance and intermediate analyses. A practical immobilized system fabricated by anchoring metallacages onto molecular sieves retains over 80% of its initial activity over six consecutive cycles. This work establishes the molecular-level integration of adsorption and photocatalysis in supramolecular architectures, providing a highly efficient approach to address persistent organic pollutants.