ZnFe2O4/Cr2O3/MXene nanocomposite photocatalyst stimulates tetracycline antibiotic degradation under visible light irradiation: Toxicity evaluation and degradation mechanism

초록

Antibiotics containing tetracycline (TC-HCl) pose a risk to both human and natural ecosystems. MXene-based nanostructures achieve rapid photodegradation of antibiotics due to their distinctive structural and physicochemical properties. This study used hydrothermal method to synthesize the ZnFe2O4/Cr2O3/MXene nanocomposite (NC). MXene (Ti3C2) was employed as a co-catalyst with a distinct layered structure. After 60 min of exposure to visible light, the TC-HCl photodegradation efficiency reached 94.2 %. In addition, the recyclability test confirmed that the ZnFe2O4/Cr2O3/MXene NC remains stable during the photodegradation of tetracycline. Following four cycles, a degradation efficiency of up to 86 % is maintained. The antibiotic was found to degrade by the action of free radicals center dot O-2(-) and center dot OH, which prompted the proposal of plausible degradation mechanisms. The ESR analysis verifies the presence of DMPO-center dot O-2(-) and DMPO-(OH)-O-center dot, and it also shows that the signals were stronger as the visible irradiation period stretched to 15 min. In addition, the breakdown routes of TC photodegradation were identified using LC-MS spectrometry. The kinetics of photodegradation were studied, and the findings showed that the reaction was rapid, with a K value of 0.0983 min(-1). Thus, the ZnFe2O4/Cr2O3/MXene nanocomposite is a promising candidate for toxicity testing and the treatment of wastewater owing to its high degrading efficiency and durability.

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