Photodegradation of Tramadol Using α-Fe2O3 nanoparticles/ 12-tungstosilicic Acid as an Efficient Photocatalyst in Water Sample Employing Box-Behnken Design

In this study, a photocatalyst based on the combination of a polyoxometalate (12-tungstosilicic acid) and a nanoparticle (α-Fe2O3) was prepared to investigate its ability to degrade Tramadol from water samples. The structure, morphology, and functional groups of the synthesized photocatalyst (α-Fe2O3/ 12-tungstosilicic acid) were characterized using SEM images, EDX pattern, TEM image, FAM images, and FTIR spectra. Due to the high surface-to-volume ratio in nanoparticles and high intramolecular charge transfer by polyoxometalates, the combination of α-Fe2O3 nanoparticles and 12-tungstosilicic acid as a photocatalyst exhibits a high photodegradation efficiency in a suitable time toward the tramadol degradation. Besides, several factors affecting the degradation process of Tramadol with the prepared photocatalyst were evaluated using an experimental design method based on Box-Behnken design to reduce the number of experiments and study the interaction between the factors. In optimal conditions, the tramadol concentration, pH of the sample solution, photocatalyst amount, and the hydrogen peroxide concentration were optimized, which were 90.0 mg L^-1, 300 mg L^-1, 7.6, and 0.6 mg L^-1, respectively. The study of the photocatalyst activity and the degradation kinetics for the tramadol photodegradation as a pharmacological contaminant in a water sample under ultraviolet irradiation exhibited that the synthesized photocatalyst had a high photodegradation efficiency with a pseudo-first-order rate constant of 0.0232 min^-1 for a photodegradation time of 70 min.