Synergetic effect of photocatalysis and peroxymonosulphate activated by MIL-53Fe@PDI Z-scheme heterojunction photocatalyst for removal of doxycycline hydrochloride

Abstract

Through a simple grinding procedure, MIL-53Fe@PDI, a novel Z-scheme photocatalytic material, was synthesized. MIL-53Fe showed minimal photocatalytic activity under visible light for the degradation of doxycycline hydrochloride. Upon composite formation with PDI (perylene-3,4,9,10-tetracarboxylic diimide), the photocatalytic performance of MIL-53Fe significantly improved. The improvement was credited to the effective separation of carriers enabled by the Z-scheme heterojunction of MIL-53Fe@PDI, which hinders the recombination of electrons and holes generated by light. MIL-53Fe@PDI was utilized to enhance the breakdown effectiveness of doxycycline hydrochloride by triggering peroxymonosulphate in the presence of visible light. Thorough examinations were carried out to analyse how the amount of peroxymonosulphate, the concentration of doxycycline hydrochloride, various inorganic anions, and natural organic matter impact the activation of peroxymonosulphate for the degradation of doxycycline hydrochloride. Experiments involving radical quenching and analysis using electron paramagnetic resonance verified the activation mechanism of MIL-53Fe@PDI with peroxymonosulphate, indicating the significant involvement of sulphate and superoxide radicals in the degradation of doxycycline hydrochloride. Predictions of potential susceptible locations and routes of doxycycline hydrochloride were made using density functional theory calculations utilizing the Fukui function and UPLC-MS. Toxicity Estimation Software Tool indicated a gradual reduction in toxicity during the degradation of doxycycline hydrochloride. This study presents an effective and environmentally friendly approach for treating antibiotic wastewater.