Sonocatalytic activity of LuFeO3 crystallites synthesized via a hydrothermal route

Abstract

LuFeO3 crystallites of different sizes and morphologies were synthesized via a hydrothermal route. The sonocatalytic properties of the as-synthesized samples were investigated by degrading various organic dyes, including acid orange 7 (AO7), rhodamine B (RhB), methyl orange (MO), and methylene blue (MB), under ultrasonic irradiation, revealing that they exhibit excellent sonocatalytic activity toward the degradation of these dyes. Particularly, the synthesized bar-like particles with lengths of ∼3 μm and widths of ∼1 μm have the highest sonocatalytic activity, and the degradation percentage of AO7 reaches 89% after 30 min of sonocatalysis. The effects of inorganic anions such as Cl−, NO3−, SO42–, PO43–, and HCO3− on the sonocatalysis efficiency were investigated. Hydroxyl radicals (•OH) detected by fluorimetry using terephthalic acid as a probe molecule were found to be produced over the ultrasonic-irradiated LuFeO3 particles. The addition of ethanol, which acts as a •OH scavenger, leads to quenching of •OH radicals and a simultaneous decrease in the dye degradation. This suggests that •OH is the dominant active species responsible for the dye degradation.