Investigating the photocatalytic removal of amoxicillin from aqueous solutions by Fe-TiO2@Fe3O4 magnetic nanoparticles. Characteristics/effect of parameters/kinetic study

In the present work, sol-gel and co-precipitation techniques were used for the synthesis of Fe-TiO2@Fe3O4 nanoparticles (NPs) and Fe3O4, respectively. These nanoparticles were used for the photocatalytic removal of amoxicillin. and the characteristics of the nanoparticles were analyzed via Energy Dispersive X-ray Spectroscopy) EDX(, field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy) FT-IR(, Vibrating Sample Magnetometer) VSM(, X-ray diffraction) XRD(, Brunauer Emmett Teller (BET), and Diffuse reflectance spectroscopy (DRS). The effect of different parameters, like pH (11-3), number of NPs (100-200 mg), and amoxicillin primary concentration (40-80 mg/L), on the amoxicillin photocatalytic elimination by the OFAT method (one factor at a time) at diverse times (0-75 min), was studied. The mean size of Fe-TiO2 and Fe3O4 NPs is 15.05 and 18.12 nm, respectively. The incorporation of iron into titanium dioxide acts as an intermediate energy level, reducing the band gap and shifting the light absorption to the visible range. Chemical bonding and stretching vibrations related to the hydroxyl group (structural water OH and hydroxyl group) were observed in the FT-IR results. The optimum results for the maximum elimination effectiveness of amoxicillin and the maximum reaction rate constant were achieved at a pH of 7. The weight of NPs is 600 mg and the primary concentration is 40 mg/L in 75 min of reaction time. The photocatalytic elimination effectiveness of amoxicillin decreased from 99.9% to 89% after five recycling steps.