RSM-BBD optimization approach for degradation and electrochemical sensing of Evan’s blue dye using green synthesized ZrO2–ZnO nanocomposite

Abstract

The Zirconium Oxide-Zinc Oxide (2ZrO2-7ZnO) nanoparticles (NPs) were successfully synthesized by solution combustion method using Basella alba raw juice at 600oC. We investigated the properties of the ZrO2-ZnO NPs via characterizations like X-Ray powder Diffraction, Energy Dispersive X-ray analysis, Scanning Electron Microscopy, Transmission Electron Microscopy, Fourier Transform Infrared Spectroscopy and Brunauer–Emmett–Teller analyses. X-ray powder diffraction studies revealed that the cubic ZrO2 and hexagonal wurtzite ZnO having the average particle size was found to be 12.6 nm and was 10.8 nm. The influence of contact time, initial dye concentration, and pH were among the independent variables used in the study. At a fixed dye concentration and catalytic load, a series of photocatalytic tests were carried out at an identical experimental condition. ZrZn4 has a high degradation capability, and it degraded 100% of the dye in 90 min. The Response Surface Model (RSM) was used to optimize and describe the interdependencies of the different variables. The method was evaluated using the Box-Behnken design (BBD). Under the constraints, the best conditions for EB elimination are 1.25 mg/L dye concentration at pH 12.0 and a contact time of 60 min, with a 99% response. A second-order polynomial model was used to understand the experimental results, and the effectiveness of the chosen model was verified by the strong agreement in determination coefficient values. The possible use of the 2ZrO2-7ZnO NPs as electrode modifier for EB sensing purposes was then evaluated using carbon paste electrodes, using cyclic voltammetry.