Photocatalytic degradation of linezolid antibiotic from aqueous solution by magnetically separable nanoheterostructure Fe3O4/ MgAl2O4/BiOBr0.5Cl0.5 synthesized Composite catalyst

The photocatalytic system has been emerging as a practical method for antibiotic removal in an aqueous medium. In this study, novel MgAl2O4/BiOBr0.5Cl0.5 heterojunction was synthesized by the decoration of different mass percentages of MgAl2O4 nanoparticles (10, 20, and 30 %) on the BiOBr0.5Cl0.5 solid solution and used for the photocatalytic degradation of linezolid antibiotic. Also, to facilitate easy separation of 10 %MgAl2O4/BiOBr0.5Cl0.5 from the solution after use, it was magnetized by Fe3O4 as 2 %Fe3O4/10 %MgAl2O4/BiOBr0.5Cl0.5. Synthesized photocatalysts were characterized by XRD, XPS, Raman, FESEM, TEM, EDX, BET-BJH, DRS, PL, Mott–Schottky, VSM, and pHpzc analyses to specify the synthesized photocatalysts and determine their chemical and physical properties. In addition, the influence of experimental parameters, including pH of the initial solution, the dosage of photocatalyst, and linezolid concentration on the performance of photocatalyst in linezolid removal, were elucidated in this study. The results showed that 10 %MgAl2O4/BiOBr0.5Cl0.5 photocatalyst was the optimal sample with a maximum removal efficiency of 95.59 % within 90 min under optimal experimental parameters (1 g/L catalyst, 10 mg/L linezolid, pH = 6.5). The kinetic studies revealed that the degradation rate of 10 %MgAl2O4/BiOBr0.5Cl0.5 photocatalyst was approximately 1.8, 2.7, 2.0, and 6.3 times faster than 20 %MgAl2O4/BiOBr0.5Cl0.5, 30 %MgAl2O4/BiOBr0.5Cl0.5, BiOBr0.5Cl0.5 photocatalyst and photolysis, respectively. Scavenger tests conducted in the same process operation revealed that h+ and •O2– play the predominant roles in linezolid photocatalytic degradation. The 2 %Fe3O4/10 %MgAl2O4/BiOBr0.5Cl0.5 photocatalyst was easily collected by magnet after each use for the next run, and its activity after five runs has reached 90 %.