Study On Preparation And Photocatalytic Properties Of Calixarene-acetate/TiO₂(CA/TiO₂) Hybrid Materials

The inorganic-organic hybrid materials is the fourth era materials after single hybrid materials, complex hybrid materials and grads hybrid materials, especially the character of combining properties of organic and inorganic components and optimizing holistic properties of organic-inorganic hybrid materials, which has been attracted the interest of many researchers. Hybrid materials suffer titanium dioxide regard as inorganic materials is one of well-known hot research materials and has been applied in many fields, such as optical, magnetic, catalytic and thermal steady properties. Calixarenes as the third host molecule in the supramolecular chemistry, have attracted considerable attentions. Due to calixarenes contain a hydroxyl array, a three-dimensional cavity and several reactive positions, they are broadly used as building blocks to construct supramolecular complexes and they usually exhibit good recognization abilities for alkali metal, transition metal and heavy metal cations, etc, which make them have widely potential in the field of analytical chemistry, ion sensors, etc. Therefore, with both of titanium dioxide and calixarene derivatives, some new inorganic-organic hybrid materials were prepared by sol-gel process. The main contents of this dissertation are as follows:1. The Calix[4]arene-acetate and Calix[6]arene-acetate (CA[4,6]) were synthesized by calixarene[4] and calixarene[6]. According to the fluorescent analysis, the supermolecular behavior between (CA) and naphthalene can be observed, The Calixarene-acetate still had calixarene the supermolecular behavior.2. Then, the hybrid materials CA[4]/TiO₂ and CA[6]/TiO₂, with existing the strong action between TiO₂ phase and the polymer matrix in the hybrids, were prepared by sol-gel process using Ti(OC₄H₉)₄ as the inorganic precursor and calixarene[4, 6] as the organic precursor. The solvent extraction and FT-IR results showed that there was a chemical bond between the TiO₂ phase and the polymer matrix in the hybrids. The microstructure and the performances of such CA[4]/TiO₂ and CA[6]/TiO₂ hybridization materials were investigated through the methods of XRD, SEM and TGA. The results showed that at w(TiO₂)=50%, 60%, CA[4]/TiO₂(50%) and CA[6]/TiO₂(60%) hybridization materials acquired more excellent thermal stability and intermolecular regularity. 3. The photocatalytic properties of the hybrid, CA[4]/TiO₂ and CA[6]/TiO₂ were studied using methyl orange as an organic contamination model. The hybrid materials exhibit higher photocatalytic activity than TiO₂ colloid. We also discussed the catalysis performance of Calixarene-acetate content to hybrid materials, it's discoved that with the Calixarene-acetate content increasing, the hybrid materials gradually enhances to the methyl orange photochemical catalysis decolorization rate. When w(TiO₂)=50%, 60%, CA[4]/TiO₂(50%) and CA[6]/TiO₂(60%), hybridization materials exhibit higher photocatalytic activity than other hybridization materials. Taking the CA[4]/TiO₂(50%) and CA[6]/TiO₂(60%) as a example, we found that the several basic features influenced the photocatalytic activity of CA[4]/TiO₂ and CA[6]/TiO₂, such as catalyst amount, initial concentration and pH value of the dye solution, based on the degradation of methyl orange under UV-light irradiation. The results show that the best photocatalytic activity of CA[4]/TiO₂(50%) and CA[6]/TiO₂(60%) can be obtained when the amount of CA[4]/TiO₂(50%) and CA[6]/TiO₂(60%) are all 0.04 g and the initial concentration and pH value of methyl orange are 4 mg/L and pH=2, respectively. Also CA[6]/TiO₂(60%) catalyses performance is better.