Morphology Control of Pseudobrookite-Type MgTi₂O₅ Powders by LiF Doping

Abstract

Well-controlled fine MgTi 2 O 5 powders, with pseudobrookite-type structure, are desired toward various industrial applications, however, commercial powders are hardly available to date. In this study, we focused the processing and characterization of well-controlled MgTi 2 O 5 powders with/without LiF additive. MgCO 3 (basic) and TiO 2 anatase powders with/without 0.5 wt. % LiF additive were calcined in air at 1100 °C for 2 h to obtain the MgTi 2 O 5 powders. SEM observation revealed that the non-doped MgTi 2 O 5 powder consisted of equiaxed particles with the diameter of 0.5-1.5 m, whereas, the LiF-doped MgTi 2 O 5 powder consisted of elongated particles with the length of ~ 5-10 m and the diameter of ~1.0-1.5 m. The smooth surface of elongated MgTi 2 O 5 particles demonstrates the effect of LiF doping as a flux, i.e., liquid phase formation during the reaction.

Pseudobrookite-type MgTi2O5 water purification filter with controlled particle morphology

“…The flow-rate was calculated by using the filtrate volume and the filtration time. Some equiaxed particles found in the samples with ≥0.5 wt.% of LiF can be attributed to MgTiO 3 particles, as reported in our preliminary study [16], which was in good agreement with current XRD results in Fig. 3.…”

“…As for our previous work [16] Saitama, Japan), TiO 2 anatase powder (99.9% purity, Kojundo Chemical Laboratory Co. Ltd.) and LiF powder (98.0%, Wako Pure Chemical Ind., Ltd, Osaka, Japan) were used as the starting materials. LiF acts as a mineralizer.…”

“…Thus, it is applicable for next-generation diesel particulate filters (DPF) [10,11], also as other applications such as thermistor [12], white pigment [13], catalyst [14], and photocatalyst [15]. Recently, we have briefly reported the synthesis of elongated MgTi 2 O 5 particles from MgCO 3 (basic) and TiO 2 anatase powders with 0.5 wt.% LiF doping [16]. The morphology of MgTi 2 O 5 can be controlled with or without LiF additive.…”