Visible light-driven metal-free porphyrin assembly-activated peroxydisulfate for the degradation of organic pollutants.

Advanced oxidation technologies that utilise sulfate radicals (·SO₄^-) hold significant potential for wastewater treatment applications. Employing photogenerated electrons of semiconductor to activate the persulfate system is possible to enhance the efficiency of charge separation in photocatalysts and improve the photocatalytic oxidation ability. This study aims to further enhance the efficiency of photogenerated charge separation of metal-free porphyrin supramolecular photocatalysts and to develop environmentally friendly catalysts for activating peroxydisulfate (PDS). Specifically, the performance of a visible-light-driven metal-free porphyrin aggregate-based photocatalytic system (CTAB-TCPP/PDS) for the degradation of phenol was investigated. The phenol degradation rate of the CTAB-TCPP/PDS system increased by 87% compared to that of pure TCPP catalyst. The separation efficiency of photogenerated carriers can be significantly improved by utilising the photogenerated electrons from porphyrin aggregates to activate PDS. Additionally, various reactive species, such as holes and sulfate radicals, can effectively work together to degrade phenol.