BNQDs and Fe2O3QDs co-doped in porous g-C3N4 for accelerating photogenerated electron migration and enhancing photo-Fenton catalysis efficiency

Abstract

With the maturity of advanced oxidation processes, photo-Fenton synergistic catalytic technology, as one of them, has become an irreplaceable strategy in environmental treatment and other fields. However, this technology suffers from drawbacks such as facile recombination of electron-hole pairs (e-/h+), low conversion efficiency between Fe3+ and Fe2+, and limited active sites. To address these issues, this study constructs a photo-Fenton synergistic system based on porous g-C3N4 (FBNCN) modified with BNQDs and Fe2O3QDs. Among them, the porous g-C3N4 provides more active sites and larger quantum dot anchoring space for the catalytic reaction. The introduction of the BNQDs effectively traps the hole (h+), reduces e-/h+ recombination, facilitates the photo-generated electrons leap, and accelerates charge transfer, while the anchoring of Fe2O3QDs enables efficient the migration of active sites and charges. This results in improved conversion efficiency between Fe3+ and Fe2+, leading to enhanced generation of ·O2- and ·OH species that exhibit excellent visible-light-catalyzed oxidation ability. Moreover, remarkable degradation efficiency was achieved for antibiotic organic pollutants (tetracycline hydrochloride, chlortetracycline hydrochloride, norfloxacin, amoxicillin) per unit of time using this catalyst system, thus providing a new method for antibiotic organic pollutant degradation. In-situ XPS technique was used to analyze the movement direction of the photogenerated charges of the composite photocatalytic materials and reveal the degradation mechanism under the synergistic system.