The Structural Investigation and Photocatalytic Application of Sol-Gel Auto-Combustion Derived ZnAl2O4 Spinel for the Degradation of Organic Dye

Abstract

Herein, we have synthesized ZnAl₂O₄ aluminate by the sol-gel auto-combustion method and sintered at 900 °C. Rietveld refinement analysis of XRD data confirmed the formation of the normal spinel structure with the Fd3m space group. The crystallite size was calculated by using the Debye-Sherrer and W-H plots and was found to be 78 and 91 nm, respectively. Field emission scanning electron microscopy (FESEM) investigation revealed the polyhedral texture of synthesized aluminates with considerable porosity. The optical properties were investigated by using a UV-Vis spectrometer and the band gap was approximated to be 3.4 eV. The synthesized aluminate was also employed for the degradation of Crystal violet (CV) organic dye pollutant under solar light irradiation. It has been observed that the percentage degradation of dye was increased with contact time and significant removal of 80 % was achieved after 120 minutes. The degradation process followed the pseudo-first-order kinetic model. These insights might be significantly advantageous for environmental applications, including dye removal from aqueous solutions for wastewater remediation.