In this study, a novel cobalt-based metal-organic framework (MOF 2) was synthesized, and its excellent performance in the PMS-activated photocatalytic degradation of RhB was demonstrated, achieving a degradation efficiency of 99.4% within 12 minutes. Comparative studies confirmed its superior catalytic activity compared to Fe- and Ni-based isomorphs (MOF 1 and MOF 3), highlighting the crucial role of the cobalt active site. MOF 2 exhibited remarkable operational stability over a wide pH range and in the presence of various coexisting inorganic anions and seawater, revealing its practical application potential in complex aqueous matrices. Mechanistic studies identified singlet oxygen and superoxide radicals as the primary ROS in the catalytic process. The limited involvement of hydroxyl and sulfate radicals, coupled with the observed charge transfer behavior, further indicates a significant contribution from non-radical pathways. These findings collectively demonstrate a unique bimodal activation mechanism combining ROS-driven and electron transfer pathways. This study not only establishes MOF 2 as a promising multiphase catalyst for sustainable water purification but also provides meaningful mechanistic insights into the selective generation and utilization of singlet oxygen and superoxide radicals in photocatalytic systems, offering rational design strategies for MOF-based environmental catalysts.
Article link: https://doi.org/10.1021/acs.inorgchem.5c03253