Photocatalytic degradation of paracetamol using photo-Fenton-like metal-organic framework-derived CuO@C under visible LED

Metal-organic framework (MOFs) based photocatalysis has received great attention recently as a promising technology for sustainable environmental applications. Herein, hydrogen peroxide (H₂O₂) activation with a copper-based metal-organic framework-derived catalyst (CuO@C) was applied for the photodegradation of a widely used analgesic paracetamol drug (PCM) under an energy-efficient visible light-emitted diode (LED) as a light source for the first time. The incorporation of CuO@C with H₂O₂ offered a photo-Fenton-like reaction that accelerated the PCM photodegradation, where 95% of paracetamol was degraded in 60 min. Interestingly, a novel N-curve pH trend was observed due to an independent boost of the PCM degradation at extreme pH_i 9.9. The redeposition of Cu to the CuO@C surface is likely the critical mechanism for minimizing Cu leaching and maintaining good catalyst reusability. Eight intermediates were identified and two of them were newly reported. Surprisingly, no dimerization route was observed as previously reported in other processes. Additionally, a mineralization degree of 68% was achieved which proved the merit of the CuO@C/H₂O₂/visible LED process for practical applications. This work can provide new insights on the application of Cu-based MOFs as rationale candidates for the remediation of emerging contaminants in wastewater by H₂O₂ activation.