On the Role of NaCl Addition to Phase Transformation of TiO2 from TiCl3

Phase transformation of TiO2 (titanium dioxide) nanoparticles has been analyzed by observing the effect of NaCl addition to the anatase-to-rutile phase transformation. NaCl is one of key points in the transformation of rutile. Co-precipitation method was employed in which TiCl3 as precursor was reacted with HCl 2M and subsequent NH4OH. Three methods were studied, namely solution without NaCl addition (TiCl3 + HCl + NH4OH) as control solution subjected to route A (TiCl3 + HCl – NaCl– NH4OH – heated at 600°C for 5 hours) and route B (TiCl3 + NaCl – heated 200°C for 5 hours – NH4OH – heated 200°C for 6 hours). Route B was subjected to heating at 200°C. The results show that without NaCl it enhanced the crystal growth of the rutile embryos allowing the ease of rutile formation at 600°C, while route A promoted the transformation of brookite and hindered anatase-to-rutile transformation as indicated by the presence of anatase at 1000°C. On the other hand route B is potential for being further explored.