The Hydrothermal Synthesis Of Nano-TiO₂ And Study On Its Crystal Growth

In recent years, as one of the most important oxides, Ti O2 has been widely investigated due to its numerous applications in photovoltaic cells, photocatalysis, Li-ion battery materials and so on. Especially if the titanium Ti O2 as photocatalyst, it make the air clean, which can eliminate 25 % to 45 % of nitrogen oxides in vehicle emissions, and deal with the terrible air pollution with high content of suspended particulate matter of PM2.5.In this paper, the nano-titanium dioxide powder were prepared by hydrothermal method, and used SEM and XRD characterization of the different morphologies of titanium dioxide, to analyze the impact of each variable on its morphology.① The morphology of Ti O2 depends on the environment composed with alkali, H2O2, temperature and reaction time etc, where H2O2 plays an important role in the porosity and formability of the products. In the reaction, hydrofluoric acid has three functions: dissolving titanium powder, slowing the hydrolysis and decreasing surface energy. Adding H2O2 can speed up the hydrolysis and promote the formation of spherical morphology. The growth mechanism of hydrothermal synthesis of nano Ti O2 was also analyzed, and many simple models of the growth mechanism were given.② Different temperatures have different effects on the morphology of Ti O2 prepared by hydrothermal method, and the most suitable temperature is 150°C. With the extension of reaction time, Ti O2 powder generated gradually, we can get to know the best reaction time is 2h.③ In the environment of KOH, Ti O2 was the fiber aggregates, and the environment of Na OH was separate chrysanthemum nanospheres. And the concentration of alkali solution directly affects the morphology of nano-Ti O2, where formability and porosity was best in the concentration of 10 mol / L. Result proves that PEG can improve the morphology of Ti O2.