Dissertation
Dissertation > Environmental science, safety science > The basic theory for the Environment and Science > Environmental Chemistry > Environmental Analytical Chemistry

Study of the Relativity between the Capability of Mercapto-azobenzenes Photocatalytic Degradation and Molecular Structure

Author ZhangSiTing
Tutor ZhangXiaoYi
School Guizhou Normal
Course Environmental Science
Keywords Thiol azobenzene Electronic structure Photocatalytic Degradation Quantum chemical calculations Degradation rate
CLC X132
Type Master's thesis
Year 2008
Downloads 83
Quotes 0
Download Dissertation

Molecular electronics mercapto-azobenzene compound widely used in molecular electronics devices the different substituents sulfhydryl azobenzene derivatives TiO2 photocatalytic degradation and the use of quantum chemical calculations to study a variety of synthetic products structure of the correlation between the sulfhydryl azobenzene derivatives molecular electronic structure of TiO2 photocatalytic degradation. For different types of substituents, the subject, the design that the precursor mercapto azobenzene derivatives, R = (-CH3,-OCH3,-SH, H,-SO3H,-COOH groups), and synthesis of the corresponding target molecule. PH value of the solution, the reaction temperature, photocatalyst dosage, H2O2 concentration and other factors affect the degradation rate of photocatalytic oxidation of sulfhydryl azobenzene derivatives research shows that when the solution PH = 8, the amount of catalyst 2.0 g / L, and the concentration of H2O2 4mmol / L, temperature degradation at 200C when the best results. Under these conditions, the completion of mercapto-azobenzene compound TiO2 photocatalytic degradation experiments. Sulfhydryl azobenzene derivatives research Gaussian03 (7.0) B3LYP method in the program, in the 6-31G ** level, POP for key words, the electronic structure calculations, and add keywords SCRF compounds in aqueous solution solvation state calculation; take advantage of time-dependent density functional method TD-the B3LYP hybrid sulfhydryl azobenzene derivatives electronic spectra were calculated in the 6-31G ** level. Calculated the electronic structure information and Degradation experimental data, analyze the relationship between the molecular structure of sulfhydryl azobenzene derivatives with TiO2 photocatalytic degradation rate and found that the correlation between the different substituents with thiol azobenzene derivatives photocatalytic degradation rate resistance: pull the electronic effect of the substituent so that the molecular dipole moment increases molecular HOMO-LUMO energy gap of the HLG reduced, PH-C bond length increases, the electronic excitation energy is reduced, as compared with the parent, such substituents derivatives catalytic degradation rate of increase; contrast, has pushed the effect of electron-substituents lower photocatalytic degradation rate of mercapto-azobenzene compound. The study showed that the sulfhydryl azobenzene molecules photocatalytic degradation of the correlation between performance and molecular structure through the molecular structure parameters to clarify the causes and mechanisms of substituents photodegradation rate differences, further in-depth study for photocatalytic degradation The experimental study and application to provide meaningful theoretical basis.

Related Dissertations
More Dissertations