Hydrothermal synthesis of KTi2(PO4)3, α-Ti(HPO4)2·H2O and γ-Ti(PO4)(H2PO4)·2H2O from a lepidocrocite-type titanate. Issue 3 (3rd July 2019)

• Record Type: Journal Article
• Authors: Kumada, Nobuhiro; Imase, Akihito; Yanagida, Sayaka; Takei, Takahiro; Miura, Akira; Itoi, Nobuki; Goto, Toshiki
• Is Part Of: Journal of Asian ceramic societies. Volume 7:Issue 3(2019)
• Page Start: 361
• Page End: 367
• Publication Date: 2019-07-03
• Subjects: A. oxide -- B. solvothermal -- C. X-ray diffraction -- D. Thermal expansion; Ceramics -- East Asia -- Periodicals; Materials science -- Periodicals; 620.1405
• DOI: 10.1080/21870764.2019.1649041
• Languages: English
• ISSNs: 2187-0764

Abstract

ABSTRACT: A potassium titanium phosphate, KTi2 (PO4 )3, and two types of hydrated titanium phosphates, α-Ti(HPO4 )2 ·H2 O and γ-Ti(PO4 )(H2 PO4 )·2H2 O, were prepared by hydrothermal reaction using a layered lepidocrocite-type titanate as a starting compound. When layered lepidocrocite-type K0.7 (Li, Ti)2 O4 (Lss; Ohtsuka Chemical Co., Ltd.) was used at a reaction temperature of 180°C, KTi2 (PO4 )3 was obtained. The crystal structure of KTi2 (PO4 )3 was a NASICON-like rhombohedral one with a low thermal expansion coefficient. The thermal expansion coefficient of KTi2 (PO4 )3 was determined using synchrotron X-ray powder diffraction data (SRXD), and the thermal expansion coefficients for the a -axis, c -axis and unit cell volume were −2.82 x 10 −6, 7.16 × 10 −6 and 1.49 × 10 −6 K −1, respectively. Two types of layered titanium phosphates, α-Ti(HPO4 )2 ·H2 O and γ-Ti(PO4 )(H2 PO4 )·2H2 O, were prepared by hydrothermal reaction using protonated titanate (Lss-H) derived from lepidocrocite-type potassium titanate (Lss) by the ion-exchange reaction.