Controllable Synthesis And Property Characterization Zno Mirco/Nanomaterials

ZnO is versatile functional material that exhibits semiconducting and piezoelectricdual properties, which suitable for high-technology such as light emitting diode,photodetectors, photodiodes, optical modulator waveguides, chemical and bio sensors,varistors, energy harvesting devices including solar cells and nanogenerators,electromagnetic coupled sensors, actuators, and so on. However, the properties ofZnO are strongly dependent on its structure and composition, including themorphology and aspect ratio, as well as the size, orientation and density of the crystal.These structural characteristics have an important role in many optoelectronic andphotocatalytic applications. Therefore, developing a shape and size controlled ZnOnanomaterials is indispensable for exploring the potential of ZnO as a source of smartand functional materials. It would contribute to the development of crystallography ofoxide materials in solutions and future inorganic devices such as sensors, solar cellsand so on. In this work, we are interested in synthesizing and preparing variousstructures of ZnO materials with hydrothermal method. And then the structures,composition, morphology, formation mechanism, optical property of the samples wereanalyzed by SEM, TEM, XRD, XPS and so on. The experimental conditions haveinfluence on the structures, morphologies, properties of products, such as reactiontemperature, reaction time, compound proportion, as well as concentration ofreactants and so on. The main work in the work is given as follows.Twined flat-peach-like ZnO material has been first obtained by hydrothermalmethod with the help of potassium citrate. Reaction temperature, reaction time,concentration of reactants, and different ligands influence the structure, morphology,property of the products. Potassium citrate plays a key role in the formation process oftwined flat-peach-like ZnO structure. The flat-peach-like ZnO, which are a newmember of the ZnO family, are of wurtzite structure and grow along the (01-10) crystallographic directions within the (0001) planes, due to the polar-field-inducedgrowth induced by interaction between the C₆H₅O₇^3-and Zn²⁺ions on Zn2+-terminatedsurface. The morphologies of products vary from spheres to twined plate-likestructure, and finally change into dumbbell-like structure with the differentconcentration of potassium citrate. So the shape and size controlled twinedflat-peach-like ZnO materials have successfully obtained. Moreover, compared withother structures, twined flat-peach-like ZnO structure exhibits better optical property,raman property, and photocurrent property and so on, which can be applied in Ramanlasers, photoelectric sensors and so on.Flower-like ZnO structure and garlic-like ZnO structure have been successfullyobtained by hydrothermal method with the assistance of potassium citrate. Reactiontemperature, reaction time, and concentration of reactants have influence on thestructure, morphology, property of the products. A possible growth mechanism wasproposed for the growth of flower-like ZnO structure and garlic-like ZnO structure.The flower-like ZnO structure is evolved from the nanoplatelets by filling withorderly packed. The shape and size controlled flower-like ZnO materials havesuccessfully obtained by altering reaction time. The garlic-like ZnO structure isevolved from the pyramid-shaped nanostructure, and further orderly attachment ofnanoparticles among the pyramid-shaped nanostructure leads to the formation ofgarlic-like ZnO structure. Potassium citrate plays an important role in the formation offlower-like ZnO structure and garlic-like ZnO structure. Furthermore, optical propertyand photocurrent property of them are excellent, which is expected to apply in optical,sensors, electronics, Catalysis and so on.Sphere-like ZnO/ZnSnO₃composite material has been successfully obtained byhydrothermal method with the help of potassium citrate. Reaction time and compoundproportion influence the structure, morphology, property of the products. Resultsshow that the products exhibits good dispersion, uniform morphology and moderategrain size when the compound proportion is1%for11h. Photoluminescencemeasurements indicate that there is a strong violet emission in such sphere-likematerial when the compound proportion is range of5%-10%. When the compound proportion is1%, the photocurrent of sphere-like material is best compared with otherproducts. Moreover, nano-crystalline ZnO/ZnSnO₃composite material has beensuccessfully obtained by hydrothermal method with the help of PEG. TheZnO/ZnSnO3composite material has uniform morphology and moderate grain sizewith4nm. Compound proportion has influence on the optical property, Ramanproperty, and photocurrent property of the products. When the compound proportionis1%, violet emission and the photocurrent of ZnO/ZnSnO3composite material arebest compared with other products. When the compound proportion is2%, Ramanproperty of ZnO/ZnSnO₃composite material is best compared with other products.Nanorod ZnO/CuO composite material has been successfully obtained byhydrothermal method with the assistance of PEG. The ZnO/CuO composite materialhas uniform morphology and moderate grain size with the length of50nm and thewidth of20nm. Compound proportion has influence on the optical property, Ramanproperty, and photocurrent property of the products. When the compound proportionis range of5%-10%, violet emission of ZnO/CuO composite material are bestcompared with other products. Raman property and photocurrent property of theproducts decreases gradually with the increasing of compound proportion.Rectangle-like ZnO/In (OH)₃composite material has been successfully obtained byhydrothermal method with the help of PEG. The ZnO/In (OH)3composite materialhas uniform morphology and moderate grain size with the length of35nm and thewidth of18nm. Compound proportion influences the optical property, photocatalysisproperty, Raman property, and photocurrent property of the products. When thecompound proportion is range of10%, violet emission of ZnO/In (OH)3compositematerials are best compared with other products. Photocurrent property of theproducts decreases gradually with the increasing of compound proportion. Ramanintensity of compound of Zn decreases gradually and Raman intensity of compoundof In increases gradually with the increasing of compound proportion. And when thecompound proportion is1%, photocatalysis of ZnO/In (OH)3composite material arebest compared with other products. Besides, photocatalysis of various complexes areinvestigated. The photocatalysis of complexes of ZnO is better than the photocatalysis of pure ZnO material. However, the photocatalysis of ZnO/In (OH)3compositematerial is the best among all the complexes.