Preparation of ZnO particle with novel nut-like morphology by ultrasonic pretreatment and its luminescence property. 
Novel nut-like zinc oxide crystal has been prepared by a low temperature hydrothermal method with the presence of Cu(2+) ion.  It seemed that the ultrasonic pretreatment was the key factor during the preparation process.  SEM observations revealed that the as-prepared ZnO crystal exhibited nut shape showing well-defined crystallographic facets.  The cross-section of the ZnO crystal was hexagonal of about 800 nm-1 microm in diameter, and the aspect ratio was a little smaller than 1:1.  The room temperature photoluminescence behavior of the nut-like zinc oxide crystal was much stronger than the reference samples.