Nano-scale mixing of TiO2·nH2O and potassium carbonate

The mixing mode of K2CO3 with anatase and hydrous titanium dioxide (TiO2·nH2O) was studied using thermoanalytical methods, XRD and TEM characterization. XRD results revealed a rather poor inter-contact in the anatase–K2CO3 system since there were no peaks attributed to potassic salts. On the contrary, the counterpart of the TiO2·nH2O–K2CO3 system demonstrated the well-defined peaks ascribed to KHCO3 and K2CO3·1.5H2O, at 25 and 300 °C, respectively. TEM characterization showed that TiO2 crystallites in the latter tended to disperse in a favourable way and the crystallite sizes were conspicuously smaller. These results suggested that the potassic salts could enter into the framework of TiO2·nH2O and restricted the further crystallite growth. Furthermore, the thermogravimetric analyses demonstrated the preferable nano-scale mixing status resulting from the reaction of K2CO3 with hydroxyl in the framework of TiO2·nH2O.