White-LED-Light-Enhanced Highly Efficient Degradation of Congo Red Catalyzed by a Hydroxo-Bridged Cu(II)-MOF as a Heterogeneous Fenton-like Catalyst

OpenAlex İngilizce

The widespread use of synthetic azo dyes in various industries has caused large amounts of polluted wastewater to be released into the environment. These dyes, such as Congo Red (CR), are toxic, mutagenic, and carcinogenic, and their high chemical stability and resistance to light and oxidation make their removal from aquatic systems particularly challenging. In this study, we investigated the catalytic performance of a newly synthesized hydroxo-bridged Cu(II)-based metal–organic framework (Cu-MOF) for the degradation of CR in the presence of hydrogen peroxide (H 2 O 2 ), under both dark and illuminated (white-LED-light) conditions. The catalytic degradation of a 100 ppm CR solution under the dark condition reached 95.4% conversion within 70 min, with a kinetic rate constant ( k ) of 0.0335 min –1, turnover number (TON) of 645.4, and turnover frequency (TOF) of 9.22, surpassing the performance reported for several other Cu-MOF examples. Under white-LED-light irradiation, the catalytic activity was further enhanced compared to that under dark conditions. This enhancement can be attributed to light-induced charge separation within the MOF structure, where photogenerated positive holes (h + ) play a key role in the degradation process. These findings suggest that hydroxo-bridged Cu-MOF is a promising heterogeneous catalyst for the efficient degradation of persistent organic dyes in wastewater treatment applications.