Pressure effect on low-temperature TiO2 synthesis

Abstract

In this study, the effect of wide range of pressure (0.1~100 MPa) on low temperature synthesis of crystalline TiO2 was investigated. Three different synthesis methods using acid catalyst, base catalyst and no catalyst were tried under three different pressure conditions such as atmospheric pressure, hydrothermal condition (about 0.27 MPa) and high pressure (10 ~100 MPa) at various temperature conditions (45 ~ 130 °C). The results showed that under atmospheric pressure, nanocrystalline anatase or rutile phase TiO2 particles were obtained under the temperature below 100 °C for all the synthesis methods. Hydrothermal condition resulted in higher crystallinity anatase or rutile TiO2 depending on the methods, however, slight reduction of specific surface area was observed. Applying higher pressure up to 100 MPa for the method using acid catalyst did not affect the resulting crystallite structure, however, slight decrease of crystallite size was observed with the increase of pressure.