Aldehyde Condensation Of Thiophene-phenylenediamine Alert Agent Sensitized Tio2 Photocatalysis

Anatase titanium dioxide has been drawn a great attention from researchers and chemists for its application to solar batteries, photocatalytic hydrogen evolution and photocatalytic degradation of organic compounds. In order to raise the photoelectric converting rate, one of measures taken is to sensitize organic dyes with the shift of light-absorption from ultraviolet region to visible region. Previous studies showed that an aromatic organic compound in structure of extended Pi-conjugated system can act as a kind of sensitizing dye for titanium dioxide. Tiophene, an isoelectronic species of naphthyridine and benzene, is constructed with relatively stable five-membered aromatic ring of sulphur atoms, and can react with organic amine through condensation reaction to produce organic dye molecules with extended Pi-conjugated structure. Therefore, it is of great theoretical and practical significance to create new thiosemiamic complexes and to research its application to sensitization of titanium dioxide, based on which the current study is conducted. The following goals are to be achieved:1.Firstly, the thiophene compounds of 1-(2-thenylidene)-2-(2-thienyl) benzoglioxaline and 2-thiophene carboxaldehyde and contracted p-phenylenediamine bis-schiff base are made by the method of condensation reaction with o-phenylenediamine, ursol, and 2-thiophenealdehyde. Secondly, the current experiment tends to improve the traditional way of preparation of thiophene compounds. That is, rare-earth salt serves as a substitution for oxidation catalyst in the traditional methods, which helps to obtain the single compound easily without any other byproducts of reaction.2. Different amount of organic compounds L1, L2 are used to modify the surface of Nanometer TiO2. Then, various modified Nanometer TiO2s are added into the photocatalytic degradation reaction of 4-NP when it is exposed to the 300mm UV-light. Afterwards, the effect of photocatalytic degradation is tested and a conclusion is reached that the best effect can be achieved when the rate of two organic compounds to Nanometer TiO2 is 20μmol:1g.3. Multiple methods are used in current experiment to produce composition with various metal cores, such as common synthesis method, template method, and hydrothermal method. Specifically, common synthesis method is applied in the production of L12CoCl2 and L12NiCl2; template method is used to produce L12CdCl2; lastly, the hydrothermal method is employed when it comes to the production of L12MnCl2. However, only the composition of Cd ionic complex is successful in the template experiment. Subsequently, four compositions are examined with elementary analysis, infrared analysis, and TG-DSC. By single crystal diffraction, it is revealed that the coordination number of four compositions is 4 and all of their structure is distorted tetrahedral structure with various extended hydrogen bond. At last, the solid fluorescence analysis is performed to investigate photoluminescent properties of these compositions.The present study has applied various ways to synthesize chemical compositions. Thus, it sheds new light on traditional synthetic methods of the ligand L1, and is of great significance for the synthesis of benzimidazoles compositions. Both of sensitized titanium dioxides can perform the function of photocatalytic degradation, and thus are the new materials to dispose waste water.