Cadrniurn-doped zinc oxide nanocrystals in the quantum confinement region have been firstly synthesized by a fast and facile sonochernical method. The alloyed structure of the nanocrystals is confirmed by X-ray diflraction, transmission electron rnicroscopy, and infrared analysis. With the increase of cadmium to zinc molar ratio from 0 to 2.0, the crystallite sizes of the samples decrease from 5.1 nrn to 2.6 nrn, and the band gaps of the samples show a red shift then a blue shift, and a red shift again. The variations of band gaps of the samples can be interpreted by the crystallite size and the composition. It is found that both the non-therrnal equilibrium environrnent established in the sonochernical reaction and the coordination ability of triethylene glycol solvent play crucial roles in the current preparation.
In this work, lanthanide doped zinc oxide nanoparticles synthesized in room-temperature ionic liquid via a sonochemical method have been studied. Firstly, the cavitation bubble temperatures in 1-butyl-3-methylimidazolium hexafluorophosphate (ImPF6) have been estimated by the methyl radical recombination method. The temperatures measured in ImPF6 are in the range of 3000-4000 K. Secondly, a facile method has been proposed to prepare lanthanide (Ⅲ) doped zinc oxide nanoparticles in ImPF6 via an ultrasonic irradiation. The nanomaterials are studied by transmission electron microscopy, X-ray diffraction, photoacoustic and luminescence techniques. The results show that the relaxation processes of the samples depend strongly on the lanthanide doping. Moreover, a mechanism is proposed to interpret the formation of lanthanide (Ⅲ) doped zinc oxide nanoparticles in the ImPF6 upon ultrasonic irradiation.
