Preparation, Microanalysis And Application Study Of The Layered Double Hydroxides

Layered double hydroxides(LDHs or HTLc) is an important inorganic functional materials. Because its special anionic layered structure, it has the alkaline, the cation adjustable performance on the layers and the anion exchangeability between the layers. So it has great application potential in the field of catalysis, ion exchange, functional polymer materials, flame retardant additive and making paper. In this paper, the LDHs were prepared combining with the research situation and the existing problems. The effect of different preparation methods, preparation conditions on microstructure of product was studied systematically. And the grow mechanism was discussed. On this basis, using methyl orange dye as the wastewater, comparative study the adsorption properties of products and the kinetics of adsorption mechanism. At the same time, the loaded LDH composite photocatalyst were preparated. We researched the immobilization technology, degradation of the photocatalyst, and disscussed the relationship between the LDHs microstrcture and the properties. The thesis is divided into five sections.In chapter 1: On the basis of the strucure and properties of LDHs, summarized the preparation methods, research status and the application progress of HTLc. In this chapter, we disscussed some problems and difficulties of this field and prospected the development application.In chaper 2: Mg Al-LDHs was prepared under hydrothermal conditions, and studied the effect of preparation conditions on the phase composition, microstructure, disscussed the grow mechanism. In this chaper, we changed the different p H value, different temperature and the time for preparating the LDHs. Using the anionic ligand growth unit theory, disscussed the grow mechanism. The results is the optimun condition is p H=12, temperature is 120℃ and the time is 18 h.In chaper 3: the Co-HTLc and Cu-HTLc were prepared respectively by hydrothermal method and discussed the growth mechanism of these HTLc. The reason says: with the Co content increasing, the particle size becomes large but the regular becmes decrease. However,with the Cu content dereasing, the particle size become larger, and the hexagonal layeredbecome more obviously.In chaper 4: As the wastewater, the methyl orange dye was applied to adsorption rsearch.comparative study the adsorption properties of products and the kinetics of adsorption mechanism. and disscussed the relationship between the LDHs microstrcture and the properties.In chaper 5: By a simple wet chemical method, the nanometer titanium dioxide loaded modified layered double hydroxides with good photocatalytic properties was prepared. Using the micro analysis method, we studied the effect of the different time, different p H value and different loading amount on the photocatalytic degradation and adsorption of photocatalytic properties. Then disscussed the degradation mechanism of composite photocatalyst.