Deep-Ultraviolet Plasmon Resonances in Al-Al₂O₃@C Core–Shell Nanoparticles Prepared via Laser Ablation in Liquid

We developed a convenient, facile, low-cost, and “green” method to synthesize nanoparticles (NPs) with deep-ultraviolet localized surface plasmon resonances (LSPRs) based on the laser ablation of an aluminum target in liquid. The nanoparticles had an Al-Al2O3@C core–shell structure, and the LSPR peak ranged from 240 to 250 nm with the increasing laser radiation time. It is found that the LSPR peak of the NPs is related to the presence of Al2O3 based on experimental characterization and theoretical simulation. The carbon shell can reduce the oxidation of Al nanoparticles and enhance the stability, which is significant for achieving the deep-ultraviolet LSPR. Moreover, we demonstrated the enhancement of the blue fluorescence intensity from CsPbBr3–xClx by Al-Al2O3@C NPs due to the stronger excitations for CsPbBr3–xClx by the enhancement of localized electromagnetic field from LSPR.