A novel Fe3O4@Pt synthetized via a self-assembly strategy as efficient Fenton-like@mimetic enzyme catalyst for degradation of tetracyclines in food processing wastewater

Abstract

The self-assembly approach has successfully been used to generate Fe3O4@Pt, a material that can mimic peroxidase. The material was created by modifying the surface of Fe3O4 nanoparticles (Fe3O4 NPs) with -NH2 functional groups using 3-Aminopropyltriethoxysilane (APTES), and then using the coordination between platinum ions and -NH2 on the surface of magnetic particles to reduce platinum ions to the surface of magnetic particles under ultrasonic conditions to produce Fe3O4@Pt composite nanoparticles. The Fe3O4@Pt core-shell composite material not only has the inert metal Pt to protect Fe3O4 to improve the stability of Fe3O4 in the biological matrix, but also has the high catalytic activity of Fe3O4 and Pt. The catalysts were characterized, and the findings revealed that they were non-homogeneous Fenton catalysts with high dispersion, uniform particle size, and a large specific surface area. Since a large number of free radicals generated during the catalysis of Fe3O4@Pt mimic enzyme can trigger the Fenton reaction, tetracycline (TC) and oxytetracycline (OTC) were chosen as target substances, and a system for the combined degradation of tetracyclines pollutants by mimic enzyme and Fenton reaction was established, and the catalytic mechanism of this system has been investigated. The findings indicate that by using a concentration of 0.25 mol/L of H2O2, a catalyst amount of 1.5 g/L, a reaction time of 50 min, and a reaction temperature of 50°C, the degradation rate of TC and OTC can exceed 97 %, following first-order degradation kinetics. Under ideal conditions, over 95 % of each tetracyclines was degraded in the simulated food processing wastewater, effectively achieving tetracyclines degradation in the actual wastewater. In addition, the reusability of the recovered Fe3O4@Pt mimetic enzyme was investigated. The findings indicated that the Fe3O4@Pt mimetic enzyme has exceptional activity, stability, and reproducibility. The combination of the Fenton reaction with the Fe3O4@Pt mimetic enzyme can expedite the degradation of tetracyclines, offering a novel approach for eliminating recalcitrant contaminants in wastewater.