Synthesis and Characterization of Nanostructured Semiconductor Materials by Self-assembling Methods

synthesis;nanoparticles;nanorods;nanospheres;self-assembling;iron oxide;Chemical Engineering

Yang, Hong

University of Waterloo

关键词: synthesis;    nanoparticles;    nanorods;    nanospheres;    self-assembling;    iron oxide;    Chemical Engineering;   

Others  :  https://uwspace.uwaterloo.ca/bitstream/10012/3528/1/yanghong-MASC-240108-ForGSO%20binding.pdf

瑞士|英语

来源: UWSPACE Waterloo Institutional Repository

【 摘 要 】

This thesis reported synthesis of TiO2 nanostructures and Fe2O3 nanostructures and studied onself-assembling process. The morphologies, compositions, and physicochemical properties ofthe prepared samples were characterized by TEM, FESEM, XRD, FTIR, UV, and SQUID etc.Nanoparticles of transition metal oxides own their special function to become an interesting hotresearch topic in the recent decades. In particular, superparamagnetic iron oxide nanoparticlescan be used as drug delivery agent and new hard disc drive materials. They have wideapplication in environment industry as well. Titanium dioxide nanoparticles can be applied inphotocatalysts, UV protectors and dye sensitive solar cell etc. Their wide industrialapplications for advanced technology development motivate scientists to develop simple,economical and novel synthetic methods, and explore their applications, so that thecommercialization of the production of the nanomaterials becomes feasible.The objective of this project is to develop an effective, simple and economical technical routefor synthesis of nanosized iron oxide and titanium oxide particles/rods/films. The approach andthe progress are outlined as follows.Based on extensive literature reading on the project related area, a novel self-assemblingtechnical route for iron oxide nanostructure and architecture was proposed which has beenconfirmed to be effective. Detailed experimental investigation on the synthesis ofnanoparticles/rods, and instrumental characterization of the particle size, structure, andcrystallites, etc. via TEM, FESEM, XRD, FTIR, UV, SQUID are conducted. Uniform nanorodsof hematite iron oxide and titanium oxide nanospheres, and anatase TiO2 thin film withmicropores have been successfully achieved. Some preliminary exploration for applications ofthe synthesized nanomaterials has also been carried out.Firstly, a novel assembled scheme of iron oxide nanostructure and architecture by selfassemblingprocess was investigated. The sol-gel technical route was employed to synthesizenearly uniform nanorods of hematite particles. Morphologies and physicochemical propertiesof iron oxide nanostructure were characterized by analytical instrument.Secondly, titanium oxide nanospheres were synthesized via a hydrothermal process usingtitanium isopropoxide as the precursor. Titanium oxide nanospheres with inner nanospace andhighly organized crystallites in the shell structure and surface regions were synthesized. Itdemonstrated that the technical route developed in this work has a high versatility for structuralengineering of various targeted morphological products.Thirdly, a simple process of preparing anatase TiO2 thin film with micropores was pursued.The synthesized nano thin film with micropores was used for the material of dye-sensitive solarcell; and effective electron transfer of titanium oxide electrode was confirmed byelectrochemical voltammetry. Preparation of the titanium oxide electrode and itselectrochemical analysis was studied. The application of the titanium oxide of microporousthin film material as a promoter for electrochemistry voltammetry measuring system wasexplored in this thesis.In conclusion, the iron oxide nanorods with superparamagnetic property were successfullysynthesized by a simple method with low cost materials. Titanium oxide hollow nanosphereswere achieved by the assistance of copolymer template. Titanium oxide thin film withmicroporous structure with significantly high efficiency in electron transfer was realized.Further researches on the synthesis of hybrid iron oxide and titanium oxide nanoparticles, theircrystal growth architecture and mechanism, as well as exploration of their applications arerecommended.