Structural Control And Properties Of Metal Oxide Semiconductors

In this paper,metal oxide semiconductors such as nickel oxide?NiO?and titanium dioxide?TiO₂?are mainly used for the main research objects.And the final target products are synthesized under different conditions by different experimental synthesis methods.We make adjustustments for the samples via controlling the reaction time,the amount of additives,the calcination temperature and other methods.It is the most commonly used method for regulating metal oxide semiconductors.The main research contents are as follows:The first chapter mainly introduces the research status of metal oxide semiconductors.We analyzed the characteristics of nano-scale metal oxide semiconductor materials by combining the characteristics of nano-materials.The preparation methods and research status of nano-metal oxide semiconductors are summarized.NiO and TiO₂ taken as objects,were analyzed according to their own characteristics.On the basis of this,combined with the above research background,the meaning of the topic and the main research contents of this thesis are further explained.In the second chapter,NiO crystals?NiO octahedron,skeleton crystal NiO octahedron and cube NiO?with different morphologies were prepared by changing the different calcination temperatures by using one-step template-free method with anhydrous ethanol as solvent.Combined with the material properties of NiO itself,the electrochemical performance of the supercapacitor electrode was analyzed.The experimental results show that the difference in electrochemical properties of NiO with different morphologies is obvious.At the same time,the structure and appearance of the prepared samples were characterized by X-ray diffractometry?XRD?and electron scanning microscopy?SEM?.The third chapter introduces nano-TiO₂ microspheres with high crystallinity and large specific surface area synthesized by simple solvothermal method.A highly catalytically active TiO₂ photocatalytic material was prepared by adjusting the amount of urea added.The results show that the prepared nano-TiO₂ microspheres have a large specific surface area.As the amount of urea added increases,the crystallinity also increases.At the same time,isopropanol as a solvent also plays a key role in the formation of nano-TiO₂ microspheres.The performance test shows that the nano-TiO₂microspheres have a unique 3D structure,which is beneficial to the transfer of electrons,and has the characteristics of high catalytic activity and good stability.In the fourth chapter,a P-N heterojunction NiO-TiO₂ nanophotocatalytic material prepared by two-step solvothermal method is introduced.The properties and morphology of the samples were characterized by XRD and SEM.The photocatalytic properties and reusability of the heterojunction were studied by using methylene blue as a simulated pollutant.The results show that the photocatalytic performance of the heterojunction is higher than that of pure NiO and pure TiO₂,which indicates that the heterojunction has better catalytic effect.In the fifth chapter,we summarize the work of the Masters and writing papers.And briefly analyze the innovation of this paper and the problems that need further research and solution in the experiment.The study of NiO and TiO₂ found that the morphology of the material and the exposure of the active crystal plane have an important influence on the photocatalytic and electrochemical properties of the nano-metal oxide semiconductor material.It provides important theoretical support for the preparation of more active metal oxide semiconductor materials in the future.