Study On New Synthesis Methods Of Inorganic Functional Materials

Because the questions of environment pollution and energy crisis were outstanding,"Green Chemistry"developed rapidly and aimed at low pollution, energy saving and less cost. We improved the synthesized methods of copper hydroxyphosphate (Cu₂OHPO₄), cadmium telluride nanocrystals (CdTe NCs), metal / titania (TiO₂) photocatalysts towards Green Chemistry.Firstly, we discovered a new way to synthesis Cu₂OHPO₄ and extended the scope of applications. In this way, the Cu₂OHPO₄ was prepared from phosphoric acid and cupric acetate dihydrate directly and optimized the reaction conditions. We found that : a) the different kinds of cupric salt did not changed the quality of Cu₂OHPO₄; b) the quantity of phosphoric acid and pH would affect on crystal plane in a certain extent; c) the crystalline perfection and the time of hydrothermal crystallization would fluctuates according to temperature. Furthermore, the ultrasonic wave and microwave were applied to assist in synthesis of Cu₂OHPO₄. And these technologies would save a great deal of time in hydrothermal crystallization. We optimized the process according to the phenol hydroxylation. Compared with the old courses, the new route improved the utilization coefficient of raw materials from 17% to more than 90%, curtail the time of hydrothermal crystallization from 3 days to about 4 hours, and the Cu₂OHPO₄ show a significant activities on the hydroxylation of phenol. Moreover, we applied the Cu₂OHPO₄ to photocatalytic degradation of Rhodamine B (RhB).Secondly, we synthesized CdTe semiconductor NCs at room temperature and accelerated by one reagent, hydrazine hydrate. Compared with the organometallic routes, aqueous synthesis is more reproducible, cheaper, and less toxic, and the as-prepared samples have aqueous stability and biological compatibility. But the temperature of aqueous synthesis was so high; as a result, the mercapto stabilizer was destroyed and brought the low quantum yield and less stability. According to the Ostwald ripping, the emission spectra were broadening with the growth of CdTe NCs. In the new route, we could receive CdTe NCs with high quantum yield (～60%), and full width at half maximum of emissions located in 30～50 nm, and the solution could kept at room temperature for more than three years. In conclusion, there were no extra energy consumption and it adapt to mass production.Finally, we prepared a core-shell photocatalyst Cu/TiO₂, and the core was Cu particle and the shell was TiO₂. Because metal particles had a favorable Fermi level, metal particles could improve the activity of photocatalysts by stabilized photo-induced electron when contacted with TiO₂. Most of the researcher chose the Au and Ag as the core, due to the poor stability of most of metal particles. We chose the Cu nanoparticles as the core; it was low cost and less environmental toxicity. Moreover, the photocatalytic activity of Cu/TiO₂ was well than P25 (a commercial photocatalyst) when degradation of RhB in aqueous.