Green synthesis of TiO2/GO/chitosan by using leaf extract of Olea europaea as a highly efficient photocatalyst for the degradation of cefixime trihydrate under UV-A radiation exposure: An optimization study with D-optimal design

Abstract

Antibiotic-resistant organisms are crucial problems, which lead to ecological disasters and cause fatal damage such as in aquatic environments and human beings. Thus, researchers have sought an effective way to minimize this issue, and they stated that the photocatalytic reaction is an effective method for degrading antibiotics. In this study, an aqueous solution containing cefixime trihydrate (CFX) was exposed to UV-A irradiation. TiO2 was used as the principal compound of the photocatalyst, known as the state-of-the-art semiconductor material. In order to reduce its band gap, dopped-graphene oxide and chitosan were impregnated in TiO2 solution. The spectrum Two FT-IR spectrometer (FTIR), X-Ray diffraction method (XRD), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) and Scanning electron microscope with energy dispersive X-Ray analysis (SEM-EDX) and thermogravimetric analysis (TGA) were used to illuminate the structure of TiO2/GO/chitosan. O-optimal design of the experiments via response surface methodology (RSM) including both numerical and categorical factors to explore the synergistic effects of process variables. The results showed that TiO2/GO/chitosan exhibited good degradation efficiency (95.34%) under optimal conditions (catalyst dose: 0.327 gL(-1), cefixime concentration: 20.29 mgL(-1), pH:4.1 and UV-A irradiation: 60 W). Statistical analysis verified the accuracy of the regression model according to the empirical data. The recycling tests showed that the prepared photocatalyst has an outstanding performance for durability and stability under UV-A irradiation. (C) 2021 Elsevier B.V. All rights reserved.