Goethite (α‐FeOOH) photocatalytic activity at natural concentrations by the addition of H 2 O 2 at neutral pH and the simultaneous presence of fluoride and bicarbonate

ALVEAR?DAZA, JOHN J.; SANABRIA, JANETH; CASTAÑO?RODRIGUEZ, VICTOR A.; CORREA?BETANCOURT, ALEJANDRA; BINET, SILVIA; SÁNCHEZ, FRANCISCO H.; MUÑOZ?MEDINA, GUILLERMO A.; GUTIÉRREZ?ZAPATA, HÉCTOR M.; PIZZIO, LUIS R.; RENGIFO?HERRERA, JULIÁN A.

Applied Research

Wiley

Lugar: New Jersey; Año: 2023

2702-4288

The effect of the simultaneous presence of fluoride (0.15–1.2 mg L−1), bicarbonates(83.6–596 mg L−1), and synthesized goethite (0.3 mg L−1) at typical concentrationsoften found in groundwater samples was evaluated on the degradation of 2,4‐dichlorophenoxyacetic acid (2,4‐D) at pH 6.9 under simulated sunlight irradiation(300 W m−2) and H2O2 concentrations of 10 mg L−1. The 2,4‐D removal was stronglyenhanced by the presence of fluoride. F− could modify the surface of iron (hydr)oxide, leading to the formation of surface Fe–F bonds benefiting the formation offree •OH, producing upward band bending, reducing the electron‐holerecombination, and enhancing the electron transfer to H2O2. On the other hand,bicarbonate may react with •OH generating CO3−• species that could participate inpollutant oxidation, while solar light‐induced H2O2 photolysis also played animportant role in removing 2,4‐D. These findings suggest that tuning of iron (hydr)oxides by fluoride could take place in real groundwater, generating photocatalystswith a high activity that could participate, by adding H2O2, in the enhancement ofsunlight photoinduced natural abiotic processes for pollutant abatement.