Preparation, Characterization And Property Study Of Binary And Trinary Metal Oxides Through A Simple Solution-Combusting Method

In recent years, metal oxides have attracted much interest because of its significantly photocatalytic properties, semiconducting performance, battery performance and potential applications in many fields. Many methods have been developed to synthesize metal oxide nanomaterials with various morphologies and sizes, including hydrothermal/solvothermal technology, microwave–assisted fabrication,γ-irradiation preparation, template-assisted route, sol-gel process, microemulsion approach, ball-milling technique, liquid–solid–solution route, ultrasonic technique, molten-salt synthesis, and so on. However, the above methods often require complex experimental equipments or/and complicated operation, which lead to high cost. Furthermore, the use of some toxic reactants or the release of toxic byproducts can cause serious environmental pollution. Therefore, it is still significant to find a simple, convenient, safe, inexpensive and environmentally friendly method for the synthesis of nanomaterials. In the current dissertation, a simple way to prepare nanoparticles, which accords with above requirements, is described. Simultaneously, the potential applications of the as-obtained nanoparticles are investigated. The main contents are listed as follows:1. Metal-ion doped TiO₂ nanoparticles were prepared via a simple solution-combusting method employing a mixture of ethanol and ethyleneglycol (V/V=30/20) as the solvent, tetra-n-butyl titanate [Ti(OC4H9)4, TBOT] as the titanium source and oxygen gas in air as the oxygen source, in the presence of small amounts of metal ions. The as-obtained products were characterized by means of powder X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS) and scanning electron microscopy (SEM). The UV-vis diffuse reflectance spectra (DRS) and photoluminescence (PL) spectra of various metal-ion doped products were investigated. Experiments showed that metal-ion doped TiO₂ nanoparticles presented stronger photocatalytic ability to the degradation of organic dyes under visible light/ 254 nm UV light irradiation than commercial P25 TiO₂ within the same time.2. Using the above synthesis method, we successfully synthesized the C/SnO₂ nanoparticles and studied their battery performance (as electrode materials for lithium-ion batteries). Experiments showed that the as-prepared C/SnO₂ composite nanomaterials possessed much higher irreversible capacity of ¹248 mAhg-1 in the first cycle. Also, the as-prepared product owned good photocatalytic activities for the degradation of organic dyes Safranine T under the irradiation of 365 nm UV light. Furthermore, the as-prepared C/SnO₂ composite nanomaterials could still be used as adsorbents for the removal of some heavy-metal ions such as Pb²⁺ and Cd²⁺ ions from water resource.3. Through this simple solution-combusting method, Aluminate nanoparticles including MgAl₂O₄, ZnAl_2O4 have been successfully prepared. The as-obtained product was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS). Research showed that the as-obtained metal aluminate nanostructures possessed large the Brunauer-Emmett-Teller (BET) surface area. Also, the as-prepared MAl2O4 (M=Mg and Zn) nanostructures presented good adsorption capacity for the removals of heavy metal ions such as Pb²⁺, Cd²⁺ and Cr³⁺ ions and good photocatalytic properties for the degradation of organic dyes.