Preparation And Property Investigation On ZnO-based Hollow Nanospheres

In this work, we prepared metal (M)-doped ZnO hollow nanospheres through colloidal carbon template method. A detailed investigation on the controllable dopant content, annealing temperature and optical properties of M-doped ZnO has been made. In addition, we prepared p-NiO/n-ZnO hybrid hollow nanospheres against the colloidal carbon template and investigated the photocatalytic performance.The primary results are described as following:1. We have prepared ZnO and Mg-doped ZnO hollow nanospheres with crystalline quality by colloidal carbon template-assistant method. The Mg contents in Zn1-xMgxO alloyed nanostructures could be controlled precisely with the tunable optoelectronic properties and reached to a maximum value as high as 48%. We found that the Mg contents in the Zn1-xMgxO alloyed nanostructures were evolutive in annealing process and it illustrated that the concentrations of Mg in Zn1-xMgxO had a fixed maximum value after annealing at a corresponding temperature.2. We give a general approach to create metal (M)-doped zinc oxide hollow nanospheres and the creation of Na/Mg/Al-doped and Na&Mg co-doped ZnO hollow nanospheres provides an excellent example of this procedure. With this combination of control, robustness, and scalability, the template assistance scheme could provide high-quality metal doped ZnO hollow nanospheres to satisfy a broad range of application needs from photoelectricity to photocatalysis.3. A new type of NiO/ZnO nanoheterojunctions was developed by the template-assisted approach. The p-n nanoheterojunctions were formed between the NiO and ZnO nanoparticles in the ultrathin shell of the NiO/ZnO hollow nanospheres. Therefore, the new type of the NiO/ZnO nanoheterojunctions could almost completely separate the electron and hole to the surface rather than wasted in the materials. Consequently, the photocatalytic activity of the p-type NiO/n-type ZnO nanoheterojctions for the degradation of rhodamine B (RhB) was much higher than that of ZnO. In particular, the p-type NiO/n-type ZnO hollow nanospheres with different Ni/Zn molar ratio exhibited diverse catalytic activity and the mechanism of which has been discussed in detail.