Matrix Effects of Different Water Types on the Efficiency of Fumonisin B1 Removal by Photolysis and Photocatalysis Using Ternary- and Binary-Structured ZnO-Based Nanocrystallites

Abstract

Several ternary- and binary-structured ZnO-based nanocrystallites (Zn2SnO4, Zn2TiO4, ZnO/SnO2, ZnO/TiO2) were synthesized by the solid-state method and first tested as photocatalysts in the removal of fumonisin B1 (FB1) under UV irradiation. The phase composition and nanocrystalline dimensions (50–80 nm) were confirmed by X-ray diffraction and Raman analyses. Similar preparation procedures applied in the case of binary structures resulted in their uniform morphology consisting of spherical particles ranging from 100 nm to 1 µm in size. However, higher synthesis temperatures of ternary oxides contributed to the growth of particles up to 10 µm. The optical energy bands of the examined photocatalysts were in the range of 3.08–3.36 eV. The efficiency of photocatalysis was compared with the efficiency of direct and indirect (sensitized by UV/H2O2 or UV/S2O82−) photolysis. The matrix effect of the different water types (Danube River, ground, and tap water) on the removal efficiency of FB1 was investigated by applying direct and indirect photolysis, as well as in the presence of the Zn2SnO4 photocatalyst. The effects of inorganic anions (Cl−, NO3−, HCO3− and SO42−), cations (Ca2+ and Mg2+), and humic acid were also investigated, since they were identified as a major species in tap, ground, and river water.