Sonocatalytic activity of LuFeO3 crystallites synthesized via a hydrothermal route

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 similar to 3 mu m and widths of similar to 1 mu m 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)-O-center dot) 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)-O-center dot scavenger, leads to quenching of (OH)-O-center dot radicals and a simultaneous decrease in the dye degradation. This suggests that (OH)-O-center dot is the dominant active species responsible for the dye degradation. (C) 2015, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.