Typical synthesis of an iron-modified Laponite @diatomite composite for photo-Fenton degradation of methyl orange dyes

Abstract

A typical adsorption modification method was employed to load ferrous ions on the Laponite@diatomite composite with 3D-2D morphology for photo-Fenton. Further, various characterization analyses were performed on the microscopic morphology and structure of the modified Laponite@diatomite. The removal ability of ferrous ion-modified Laponite@diatomite (Fe-La@D) photo-Fenton-oxidative cationic dyes under different raw material concentrations, H2O2 content, MO concentration and light environment was discussed. Its reusability and photo-Fenton mechanism were further investigated. The study found that the ferrous ion-modified Laponite @diatomite is a catalyst with good photo-Fenton performance, and the MO degradation rate in 240 min can reach 99 % under the optimal reaction conditions. After modification, ferrous ions were successfully intercalated between the Laponite layers, and the forbidden band width of the material was reduced. And with the increase of catalyst dosage and H2O2 content, the photo-Fenton reaction rate also increases. While the initial concentration of MO increases, the reaction rate decreases accordingly. Cycling tests demonstrate the structural stability and reusability of the catalyst. EPR spectra showed the generation of hydroxyl radicals, which are important substances in the degradation process. This work provides an idea for the synthesis of economical and ideal photo-Fenton catalysts, which has broad application prospects.