Artificial neural network modeling of cefixime photodegradation by synthesized CoBi2O4 nanoparticles

Abstract

CoBi2O4 (CBO) nanoparticles were synthesized by sol-gel method using Polyvinylpyrrolidone (PVP) as a complexing reagent. For a single-phase with the spinel structure, the formed gel was dried and calcined at four temperatures stages. Various methods were used to identified and characterized the obtained spinel, such as X-ray diffraction (XRD), Scanning Electron Micrograph (SEM-EDX), Transmission electron microscope (TEM), Fourier transform infrared (FT-IR), X-ray fluorescence (XRF), Raman and UV-Vis spectroscopies. The photocatalytic activity of CBO was examined for the degradation of a pharmaceutical product Cefixime (CFX). Furthermore, for the prediction of the CFX degradation rate an artificial neural network model was used.The network was trained using the experimental data obtained at different pH with different CBO doses and initial CFX concentrations. To optimize the network, various algorithms and transfer functions for the hidden layer were tested. By calculating the REVISED MANUSCRIPT mean square error (MSE), 13 neurons were found to be the optimal number of neurons and produced the highest coefficient of correlation R 2 of 99.6 %. The relative significance of the input variables was calculated and the most impacting input was proved to be the initial CFX concentration. The effects of some scavenging agents were also studied. The results confirmed the dominant role of hydroxyl radical OH • in the degradation process. With the novel CoBi2O4/ZnO hetero-system, the photocatalytic performance has been enhanced, giving an 80% degradation yield of CFX (10 mg/L) at neutral pH in only 3 hours.

Application of Bi12ZnO20 Sillenite as an Efficient Photocatalyst for Wastewater Treatment: Removal of Both Organic and Inorganic Compounds

“…As can be seen, the achieved rate of CFX degradation was 94.34% within 3 h, which demonstrated that CFX was successfully removed using BZO crystals as a photocatalyst. This degradation rate was higher than that obtained using others catalysts during our previous studies [ 13 , 14 ]. As BZO crystals have shown great degradation for CFX, it can be concluded that they can be effective catalysts for the removal of organic pollutants.…”

“…Starting with the oxidation reaction, which is responsible for the degradation of organic pollutants, in our case CFX, the holes (h + ) in the valance band react and oxidize H 2 O molecules to produce hydroxyl radicals, • OH, which are the most numerous and primary active species among the ROS in the oxidation of organic pollutants [ 1 , 13 , 63 ].…”

“…We used scavengers in our previous studies to focus on the contribution of reactive oxygenated species, and we validated that the radical most involved in the degradation process of organic compounds are OH° radicals [ 13 ].…”

Structural and Optical Properties of Bi12NiO19 Sillenite Crystals: Application for the Removal of Basic Blue 41 from Wastewater

“…This result can be explained by the gap energy of the catalyst (2.1 eV), which offers a higher absorption in both UV and visible areas from 200 to 800 mm [42]. It was already demonstrated in our previous works [13,14] that the degradation of the dye as an organic compound in the photocatalytic process is mainly due to the reactive oxidative species (ROS) such as superoxide radicals (O2  − ) and hydroxyl radicals ( • OH), where the electrons of Bi12NiO19 conduction band are degraded the Basic Blue 41 by reducing the absorbed O2 to the super-radical anion O2  − . The oxidation occurs concomitantly by radicals • OH through a valence band that reacts with H2O [43].…”

“…Therefore, its detection and elimination are challenging goals. Based on our previous studies, photocatalysis-using catalysts have successfully removed both organic and inorganic pollutants in wastewater [12,13]. A novel catalyst with high photocatalytic activity and a narrow bandgap must be developed and tested in order to achieve this goal [14].…”