CQDs drives CeO2/PbFe12O19 photocatalysts for oxytetracycline hydrochloride removal by photoinduction and magnetic recovery

The multi-dimensional integrated methods have been explored for fabrication of CQDs/CeO2/PbFe12O19 (CQDs/ CO/PFO) photocatalysts with the different CQDs contents. A variety of structural and component characterization methods have been adopted to study the phase purity and composition of CQDs/CO/PFO photocatalysts, which does not contain any other impurities except the basic constituent substances. The microstructure and optical behavior proved the formation of heterojunction between CQDs, CO and PFO, and the absorption edge was significantly red shifted compared with the CO and CO/PFO photocatalysts. The experimental results show that the CQDs/CO/PFO photocatalyst has high photocatalytic rates for the degradation of oxytetracycline hydrochloride (OTC-HCl) under simulated sunlight irradiation. The photocatalytic efficiency of CQDs/CO/PFO photocatalysts is not linearly dependent on the content of CQDs, optical absorption coefficient, energy band (Eg) value and magnetic properties. The optimal CQDs content, the magnetic squareness ratio (SQR), the initial drug concentration, the catalyst content and initial pH value were 7 mL, 0.271, 50 mg/L, 1 g/L and 10, respectively. A variety of free radical verification experiments, degradation pathways and toxicity analysis confirmed that the hole (h+) and hydroxyl radical (center dot OH) were the two primary active species in CQDs/CO/PFO photocatalysts for the degradation of OTC-HCl.