Heterogeneous photo-Fenton process mediated by Sn-substituted goethites with altered OH-surface density

LARRALDE, ANA L.; ONNA, DIEGO; FUENTES, KEYLA M.; SILEO, ELSA E.; HOJAMBERDIEV, MIRABBOS; BILMES, SARA ALDABE

JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2019

1010-6030

Heterogeneous photo-Fenton process using several pure- and Sn-incorporating goethites was investigated for the decolourisation of methyl orange (MO). The used goethites presented a partial Sn(IV)-for-Fe(III) substitution. Among other properties variations, this partial replacement provoked changes in the OH-surface density (OSD) of the oxo(hydr)oxide. The effect of Sn-for-Fe substitution on the MO decolourisation was investigated by analysing several processes that might occur when combining H2O2, UV-Vis irradiation and the iron oxides, with the dye. The best performance was achieved when a slight substitution of Sn-for-Fe was used, indicating that tin contributes indirectly to the decolourisation by increasing the OSD and assisting the reduction of Fe(III)→Fe(II) through an intermediate between tin and H2O2 (SnOOH). The proposed mechanism for the MO decolourisation using the Sn-substituted goethite involves an indirect pathway not previously reported for photo-Fenton process.