An efficient CaTiO3 nano sonocatalyst toward the dye degradation under ultrasonic irradiation

Abstract

In this work, the sonocatalytic property of CaTiO3 nanoparticles synthesized via a polyacrylamide gel route was investigated by degrading rhodamine B (RhB), methyl orange (MO) and methylene blue (MB) under ultrasonic irradiation. It is revealed that CaTiO3 particles exhibit an excellent sonocatalytic activity toward the dye degradation. The influence of various experimental parameters [reaction solution temperature, catalyst dosage, initial dye concentration, pH value, and inorganic anions (including NO3-, SO42-, H2PO4-, and HCO3 1)] on the sonocatalytic efficiency was systematically investigated. Hydroxyl (·OH) radicals were detected by fluorimetry using terephthalic acid as a probe molecule and are found to be produced over the ultrasonic-irradiated CaTiO3 particles. The addition of ethanol, which acts as a ·OH scavenger, leads to a quenching of ·OH radicals and a simultaneous decrease in the dye degradation. This suggests that ·OH radicals are the dominant active species in the present sonocatalytic reaction. In addition, the recycling sonocatalytic experiment reveals that CaTiO3 particles exhibit a good stability in their sonocatalytic activity and crystal structure.