Gear effect promoted solar photocatalytic-Fenton Rhodamine B degradation performance over Fe/TiO2

Abstract

s: The degradation of Rhodamine B (RhB), recognized as a persistent organic pollutant, has garnered significant attention. In this study, Fe/TiO₂ catalysts were synthesized by equal volumetric impregnation for the degradation of high-concentration RhB under natural conditions. Fe-modified TiO₂ can broaden the light absorption spectrum and light response, and also can improve the separation and transfer rate of photogenerated carriers. Under the sunlight, the generated e^- transfers to Fe³⁺, promotes the Fe³⁺/Fe²⁺ cycle and realizes the efficient degradation of RhB by Fenton oxidation. It has been demonstrated that the spherical Fe/TiO₂ nanoparticles exhibit a gear effect, thereby demonstrating effective degradation performance. Specifically, a combination of 0.2 g of 1.5 % Fe/TiO₂ catalyst with 1 mL of H₂O₂ resulted in 97.5 % removal of 80 mg/L RhB (100 mL) within 210 min. Even after five cycles, the removal rate remained 92 %. Furthermore, 0.1 mL H₂O₂ has been demonstrated to function as an effective promotion for the reaction. A significant degradation rate was also maintained in nearly natural environments, obviously broadening the applicable pH range. Liquid chromatography-mass spectrometry (LC-MS) was employed to analyze intermediates and proposed potential degradation pathways. This work presents a promising approach for the development of highly efficient visible light photo-Fenton catalysts.