Sono-luminescence of uranyl ions in aqueous solutions

In summary, we have observed for the first time an ultra-bright sono-luminescence of uranyl ions in acidic aqueous solutions. The intensity of UO22+ SL is strongly influenced by the presence of complexing agents, like phosphate ions, and by the ultrasonic frequency. The mechanism of UO22+ SL seems to vary with uranium concentration: sono-photoluminescence dominates in diluted solutions, and collisional excitation would add its contribution at higher UO22+ concentration. This study highlights the importance of excited uranyl quenching processes by the products of solvent sono-lysis. In light of these findings, sono-luminescence of UO22+ ions exhibits a unique behavior combining the properties typical for both photoluminescence and radioluminescence. (authors)