Novel River Sediment@ZnO-Co nanocomposite for photocatalytic degradation and COD reduction of crystal violet under visible light

This work aims to evaluate the adsorption and photocatalysis efficiency of the composite river Sediment (S)@Cobalt-doped ZnO (SZCo) with two weight ratios of 10 and 20% of ZCo/river sediment. The S@ZCo was successfully prepared using the chemical precipitation method followed by the wet impregnation method. The structure and morphology of the synthesized materials were examined using, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-Ray fluorescence technique (XRF), BET surface area, scanning electron microscopy (SEM), and UV-Vis diffuse reflectance spectra (DRS). The Box-Behnken model (BBD) was effective for modeling the experimental data of crystal violet dye (CV) photodegradation according to the results of analysis of variances showed that the ZCo amount and CV solution pH are the most influencing parameters on the process efficiency. A total removal (100%) of CV has been attained for 40 min with a high percentage (93%) of chemical oxygen demand (COD) removal using SZCo20% under visible light illumination and the optimum conditions obtained from the Box-Behnken. SZCo20% displayed high stability after five cycles. Furthermore, the activity of superoxide ions (O-2(center dot-)) and hydroxyl radicals (OH center dot) as the responsible spices for CV degradation were well affirmed by the radicals scavenging tests. Overall, these discoveries could offer additional contributions to the elaboration of new composites based on modified ZnO for various potential applications and especially photocatalysis. (C) 2021 Elsevier B.V. All rights reserved.