Fabrication and characterization of Halloysite–Fe3O4–Ag nanocomposite as efficient catalyst for metronidazole degradation by using sodium borohydride: Artificial neural network modeling

Abstract

In this work, halloysite–Fe3O4–Ag nanocomposite produced by doping Fe3O4 and Ag nanoparticles on the surface of halloysite nanotube after activation with HCl by co-precipitation method was used as a catalyst for the catalytic degradation of metronidazole antibiotic with sodium borohydride. The physical and chemical structure of synthesized nanocomposite were characterized by pHpzc, FTIR, XRD, SEM/EDX and TGA. The degradation process of metronidazole antibiotic with sodium borohydride in the presence of nanocomposite catalyst was investigated. According to this, metronidazole removal efficiency was determined as %93.1 (as 0.069 in terms of Ct/C0) at the end of 120-min contact time under determined optimum conditions (pH 7, 10 mM NaBH4 concentration, 2 g/L catalyst dosage, 25 °C temperature) for 30 ppm metronidazole solution. In the pH range in which the process is applied, metronidazole is in anionic form in solution. The used nanocomposite was efficiently recycled and it was determined that it could be reused at least 6 times as a catalyst. Moreover, the process was modeled with Artificial Neural Networks approach. Finally, it was revealed with HPLC analysis that metronidazole was converted into different products as a result of applied process.