Abstract
High quality potassium hexatitanate whiskers were hydrothermally synthesized in one step under moderate temperature and pressure conditions. Effects of the titanium source and reaction conditions on the hydrothermal reaction rate, product phase component, and morphology of whiskers were investigated. The results show that the reactivity of hydrated titania, anatase TiO2, and rutile TiO2 with KOH decreases in turn, and with hydrated titania as titanium source, it is difficult to obtain potassium hexatitanate whiskers with good morphology. In contrast, uniform potassium hexatitanate whiskers with a length of 10–20 μm and a diameter of 200–700 nm were obtained using anatase TiO2 as titanium source. The investigation demonstrates that the initial KOH concentration, annealing temperature and time, molar ratio of K2O/TiO2, etc. significantly affect the morphology of the as-synthesized whiskers. The optimized synthesis condition is as follows: anatase as a titanium source; 10 wt.% KOH solution; annealing temperature and time of 300°C and 5 h, respectively; K2O/TiO2 molar ratio of 5, etc. A rhombic potassium hexatitanate was prepared under the optimum condition and the whisker grew along the [110] direction. The reaction mechanism was discussed.
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References
Richardson M.O.W., Polymer Engineering Composites, Applied Science Publishers, London, 1977: 327.
Gulledge H.C., Fibrous potassium titanate—A new high temperature insulating material, Ind. Eng. Chem., 1960, 52: (2): 117.
Zhou Y.X., Liu C., He M., Lu X.H., Feng X, and Yang Z.H. Splitting behavior and structural transformation process of K2Ti6O13 whiskers under hydrothermal conditions, J. Mater. Sci., 2008, 43(1): 155.
Kudo A. and Sakata T., Photoluminescence of layered alkali-metal titanates (A2TinO2n+1, A; Na, K) at 300 and 77 K, J. Mater. Chem., 1993, 3(10): 1081.
Shibata M., Kudo A., and Tanaka A., Photocatalytic activities of layered titanium compounds and their derivatives for H2 evolution from aqueous methanol solution, Chem. Lett., 1987, 113(8): 1017.
Feng X., Lü J.Z., and Lu X.H., Applications of potassium titanate whiskers in composite materials, Acta Mater. Compos. Sin. (in Chinese), 1999, 16(4): 1.
Li W., Inorganic Whiskers (in Chinese), Chemical Industry Publisher, Beijing, 2005: 153.
Lee J.K., Lee K.H., and Kim H.J., Microstructural evolution of potassium titanate whiskers during the synthesis by the calcinations and slow-cooling method, Mater. Sci., 1996, 31(6): 5493.
Huang J.F. and Jin Z.M., The mechanism of melting synthesis of potassium hexatitanate, J. Salt Lake Sci. (in Chinese), 1994, 2(1): 67.
Bao N.Z., Feng X., and Lu X.H., Study on the formation and growth of potassium titanate whiskers, J. Mater. Sci., 2002, 37(5): 3035.
Bao N.Z., Feng X., and Lu X.H., Low-temperature controllable calcination syntheses of potassium dititanate, AIChE J., 2004, 50(7):1568.
Bao N.Z., Shen L.M., and Feng X., High quality and yield in potassium titanate whiskers synthesized by calcination from hydrous titania, J. Am. Ceram. Soc., 2004, 87(3): 326.
Wang C.S., Feng X., and Shi Y.J., Calcination synthesis of potassium hexatitanate whiskers with low content of water soluble potassium ions, Chem. Ind. Eng. (in Chinese), 2005, 56(5): 937.
Masaki N., Uchida S., and Yamane H., Characterization of a new potassium titanate, KTiO2(OH) synthesized via hydrothermal method, Chem. Mater, 2002, 14(1): 419.
Kajiwara M., The synthesis of potassium titanate fibres by flux evaporation methods, J. Mater. Sci., 1988, 23(10): 3600.
Lencka M.M. and Riman R.E., Thermodynamic modeling of hydrothermal synthesis of ceramic powders, Chem. Mater., 1993, 5(1): 61.
Rau H. and Rabenau A., Crystal syntheses and growth in strong acid solutions under hydrothermal conditions, Solid State Commun., 1967, 5(5): 331.
Gier T.E. and Salzberg P.L., Hydrothermal Synthesis of Alkali Metal Titanates, US Patent, 2833620, 1958.
Oota T. and Saito H.J., Synthesis of potassium hexatitanate fibers by the hydrothermal dehydration method, J. Cryst. Growth, 1979, 46(1): 331.
Sun X., Chen X., and Li Y., Large-scale synthesis of sodium and potassium titanate nanobelts, Inorg. Chem., 2002, 41(20):4996.
Masaki N., Uchida S., and Yamane H., Hydrothermal synthesis of potassium titanates in Ti-KOH-H2O system, J. Mater. Sci., 2000, 35(6): 3307.
Yahya R.B., Hayashi H., and Nagase T., Hydrothermal synthesis of potassium hexatitanates under subcritical and supercritical water conditions and its application in photocatalysis, Chem. Mater., 2001, 13(3): 842.
Meng Q.H., Li X.F., and Du Z.Q., The synthesis and structure of potassium titanates with a high ratio of length to diameter, Chemistry, 2002, 33(7): 482.
Wang B.X., Shi Y., and Xue D.F., Large aspect ratio titanate nanowire prepared by monodispersed titania submicron sphere via simple wet-chemical reactions, J. Solid State Chem., 2007, 180(4): 1028.
Yu H.Q., Yu J.Q., and Cheng B., Photocatalytic activity of the calcined H-titanate nanowires for photocatalytic oxidation of acetone in air, Chemosphere, 2007, 66(4): 2050.
Shi E.W., Xia C.T., and Zhong W.Z. Formation mechanism of barium titannate fine powder under hydrothermal conditions, J. Chin. Ceram. Soc. (in Chinese), 1996, 24(1): 45.
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Wang, J., Li, C., Liang, B. et al. Synthesis of potassium hexatitanate whiskers using hydrothermal method. Rare Metals 28, 24–32 (2009). https://doi.org/10.1007/s12598-009-0006-6
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DOI: https://doi.org/10.1007/s12598-009-0006-6