Uniformly Porous MgTi₂O₅ with Narrow Pore‐Size Distribution: XAFS Study, Improved In Situ Synthesis, and New In Situ Surface Coating

Abstract

Porous MgTi2O5 ceramics with pseudobrookite‐type structure have been prepared by in situ processing (viz. reactive sintering). In this communication, further studies have been carried out in order to evolve the porous MgTi2O5, viz., (1) X‐ray absorption fine structure (XAFS) study of porous MgTi2O5, (2) improved in situ synthesis (i.e., more precise stoichiometric control), and (3) new “in situ surface coating,” which enables in situ MgTi2O5 synthesis, in situ uniform pore formation, and in situ surface coating in only one‐step heating.

Morphology Control of Pseudobrookite-Type MgTi₂O₅ Powders by LiF Doping

“…Similarly to our previous work [6,7,9], commercially available MgCO 3 (basic) powder (99.9% purity, Kojundo Chemical Laboratory Co. Ltd., Saitama, Japan), TiO 2 anatase powder (99.9% purity, Kojundo Chemical Laboratory Co. Ltd.), and LiF powder (99.9%, Wako Pure Chemical Ind., Ltd, Osaka, Japan) were used as the starting materials. LiF acts as a mineralizer.…”

“…Magnesium dititanate (MgTi 2 O 5 ), with pseudobrookite-type structure, also has characteristic unidirectional low-thermal expansion, however, it is less crystallographically anisotropic and more thermally stable than Al 2 TiO 5 [1]. Suzuki et al have recently reported uniformly porous MgTi 2 O 5 ceramics with 3-D network structure [6][7][8][9]. By controlling the stoichiometry and the liquid phase content, idiomorphic MgTi 2 O 5 grains were formed [9].…”

“…Suzuki et al have recently reported uniformly porous MgTi 2 O 5 ceramics with 3-D network structure [6][7][8][9]. By controlling the stoichiometry and the liquid phase content, idiomorphic MgTi 2 O 5 grains were formed [9].…”

“…From our previous study [9], LiF doping is effective to control the morphology of MgTi 2 O 5 particles, however, the detail has not yet been clarified. In this study, we focused the processing and characterization of well-controlled MgTi 2 O 5 powders with/without LiF additive.…”

Semiconductor MgTiO₃, MgTi₂O₅ and Mg₂TiO₄ Double-Oxide Electrodes for Dye-Sensitized Solar Cells

“…Similarly to our previous works [5][6][7][8] O molecules, quantitative analysis of the starting powder was performed by thermogravimetry and differential thermal analysis (TG-DTA). Based on the compositional calibration using TG-DTA data, MgCO 3 (basic) and TiO 2 powders (nominally, Mg:Ti = 1:1, 1:2 and 2:1 in mole fraction) were wet-ball milled in ethanol for 24h.…”