Design and Development of the AgI/NiFe2O4 Photo-Fenton Photocatalyst

Abstract

The primary design criterion of an efficient photo-Fenton photocatalyst is that its nucleophilic center in the photoexcited state should effectively reduce H2O2 for hydroxyl radical generation. In the present research, we used DFT and TD-DFT calculations to assess and find that the AgI/NiFe2O4 composite fulfills this requirement. Besides this, both components of this composite have visible light band gaps, and the NiFe2O4 component also facilitates its easy magnetic recyclability. Given this background, a series of AgI/NiFe2O4 composites with varying AgI contents were prepared by a stepwise precipitation method. The prepared composites were thoroughly characterized by XRD, SEM, TEM, and XPS techniques. The photo-Fenton activity of these photocatalysts was evaluated for tetracycline (TC) degradation under cool white LED visible light irradiation. Photo-Fenton activity reached its optimum value at an intermediate weight percent of AgI precipitation on NiFe2O4 particles. TC degradation followed first-order kinetics. The turnover frequency of the sample with optimum photo-Fenton TC degradation activity was significantly higher than those of other photocatalysts reported in the literature. A photo-Fenton photocatalytic mechanism was proposed based on DFT and experimental results. © 2024 American Chemical Society.