Cu/Ce Bimetallic Porphyrin MOFs with Enhanced Charge Transfer for Efficient Photocatalytic–Photothermal Sterilization

Abstract

A series of bimetallic CuxCey (x = 1–5, y = 10 – x) metal-organic frameworks (MOFs) were prepared via a solvothermal method. Results reveal that the coordination between Cu2+ and the central N atoms of the porphyrin ring is consistent with partial metallation of the porphyrin macrocycle and alters excited-state and charge-transfer behavior, which contributes to the enhanced photocatalytic bactericidal activity. The Cu/Ce bimetallic sites alter the excited-state and charge-transfer behavior of the framework, which may facilitate the generation of reactive oxygen species (ROS), including singlet oxygen (1O2), while the photothermal effect derived from TCPP ligands contributes to bacterial inactivation. Under visible light irradiation (0.2 W cm–2, λ ≥ 420 nm) for 15 min, the optimized Cu2Ce8 achieves a bactericidal rate of over 99.99% against Escherichia coli (E. coli), and the bactericidal rate remains above 90% after 4 recycling cycles.