Sonophotocatalytic degradation of Acid Blue 113 in the presence of rare earth nanoclusters loaded TiO₂ nanophotocatalysts

A simple, convenient and one-step sonochemical treatment was adopted for the loading of rare earth (RE) nanoclusters such as Sm³⁺, Pr ³⁺ and Er³⁺ into the TiO₂ surface to enhance the sonophotocatalytic degradation of Acid Blue 113 (AB113). The prepared catalysts were characterized using various analytical techniques to prove that the expected modification can occur at the surface which leads to tailor the optical properties of the resulting nanocatalysts. In this study, it is proved that the visible light is sufficient for the band gap excitation of the synthesized nanocatalysts and to improve the efficiency of the mineralization process the sonicator producing 42 kHz ultrasound was combined with the photocatalysis technique. Among the experimented nanocatalysts Pr³⁺ loaded TiO₂ exhibit the higher rate of decolorization and mineralization of AB113 during sonocatalytic, photocatalytic and sonophotocatalytic processes. The synergy index for the combination of sonolysis and photolysis i.e., two advanced oxidation processes (AOPs) were calculated using the observed rate constants for the individual and combined AOPs.