Photocatalytic degradation of perfluorooctanoic acid (PFOA) from wastewaters by TiO₂, In₂O₃ and Ga₂O₃ catalysts

Abstract

<div lang="en" class="abs"><p class="abs_header">Abstract</p><p>The aim of the work was to prepare nanosized In₂O₃ and Ga₂O₃ photocatalysts for degradation of perfluorooctanoic acid (PFOA) in water. Their commercial references along with TiO₂ were used as a comparison basis. The characterization of the materials proved that successful preparation of cubic In₂O₃ and monoclinic β-Ga₂O₃ were achieved via solvothermal and hydrothermal methods, respectively. The effect of different parameters such as catalyst dosage, UV light source and utilization of inorganic oxidant in PFOA treatment were evaluated. In₂O₃, photocatalyst was the most efficient in the degradation of 15 mg L⁻¹ PFOA under UVB irradiation and synthetic air reaching 27% of degradation, which was 20 percentage points higher than for commercial In₂O₃. This is proposed to be partly due to significantly higher specific surface area of the self-made In₂O₃ and smaller crystallite size and partly due to more efficient absorption of UVB light compared to the other tested materials. Addition of KBrO₃ did not improve the activity of self-made In₂O₃.</p></div>