Controllable Synthesis Of ZNO,ZNO/CDSE Micro/Nano-materials And Their Photocatalytic Properties

Nanomaterials with superior performance, more and more cause for concern. Nanomaterials is an important part of the21st century scientific and technological development Preparation and properties of nanomaterials is the focus of the study of nanomaterials and cross-use of the disciplines of physics, chemistry, biomedical and interface science.ZnO is a key semiconductor for short wavelength electrooptical denices and low-voltage due to its large exciton binding energy of60meV and wide band gap(3.2eV). ZnO nanomaterials exhibit more optical properties and prominent electronic, and has been applied in solar cell, catalyst, piezoelectricity, gas sensor, laser generator and so on. At present, the research on applications and research on controllable synthesis of ZnO nanomaterials become attractive. The main contents of this thesis are listed as below:1. ZnO with different morphology was prepared by changing pH in the reaction system consisting of Zn(NO3)2·6H2O, Hexamethylene tetramine and CH3COONH4The morphologies and structures of the prepared materials were detailedly characterized by SEM, XRD。 The photocatalytic activities of as-prepared ZnO samples were characterized by photodegradation of Methylene blue2. In this paper, an efficient and simple route combined with a subsequent calcining process to synthesize pompon-like ZnO microstructures at room-temperature (25℃) has been developed. The samples were intensively investigated by SEM, TEM, HRTEM, XRD. The results indicate that the well-crystallized pompon-like ZnO is assembled by interlaced nanoplates with uniform thickness of about50nm. The photocatalytic trials confirm that the pompon-like ZnO exhibits excellent degradation efficiency under UV light. Moreover, the as-prepared ZnO samples show superior durability and stability after six photodegradation cycling runs. Finally, a mechanism was proposed to elucidate the photodegradation reaction of the pompon-like ZnO.3. Semiconductor based nanoscale heterostructures are promising candidates for photocatalytic andphotovoltaic applications with the sensitization of a wide bandgap semiconductor with a narrow bandgap material being the most viable strategy to maximize the utilization of the solar spectrum. Here,we present a simple wet chemical route to obtain nanoscale heterostructures of ZnO/CdSe without usingany molecular linker. We show that the heterostructures with the lowest CdSe loading exhibit an exceptionally high activity for the degradation of methylene blue (MB) under solar irradiation conditions; In particular. the absence of any molecularlinker at the interface makes our method appealing for photovoltaic applications where faster rates of electron transfer at the heterojunctions are highly desirable.