ISSN 1070-4272, Russian Journal of Applied Chemistry, 2017, Vol. 90, No. 2, pp. 193−197. © Pleiades Publishing, Ltd., 2017.
Original Russian Text © T.P. Maslennikova, O.Yu. Sinel’shchikova, N.V. Besprozvannykh, E.N. Gatina, S.K. Kuchaeva, V.L. Ugolkov,
2017, published in Zhurnal
Prikladnoi Khimii, 2017, Vol. 90, No. 2, pp. 171−175.
OF SYSTEMS AND PROCESSES
Hydrothermal Synthesis of Potassium Titanate
Nanotubes Doped with Magnesium, Nickel, and Aluminum
T. P. Maslennikova*, O. Yu. Sinel’shchikova, N. V. Besprozvannykh,
E. N. Gatina, S. K. Kuchaeva, and V. L. Ugolkov
Grebenshchikov Institute of Silicate Chemistry, Russian Academy of Sciences,
nab. Makarova 2, St. Petersburg,
Received November 29, 2016
Abstract—Study of the phase formation in the systems TiO
O (M = Mg, Ni, Al) from
crystalline and coprecipitated X-ray-amorphous mixtures demonstrated that doped potassium titanate nanotubes
can be obtained in a hydrothermal treatment of coprecipitated hydroxides in the temperature range 170‒220°C.
The average outer diameter of the thus synthesized nanotubes strongly depends on the element being introduced
and is 5 to 10 nm. The nanotubes have a large speciﬁ c surface area (200‒300 m
) and are stable up to a tem-
perature of 500°C, above which they decompose to give potassium hexatitanate. The nanotubes can be used as
sorbents, photocatalysts, and components of composite materials for frictional and construction purposes.
Alkali metal polytitanates of general formula
(M = Na, K) have, depending on n, a layered
(n = 3, 4, 5) or tunnel structure (n = 6, 7, 8) formed by zig-
zag layers of titanium-oxygen octahedra. Figure 1 shows
schematically the arrangement of layers at various values
of n . Depending on their composition and structure,
these compounds can be used as solid electrolytes, insula-
tors, sorbents, and photocatalysts and also can serve as a
basis for composite frictional and construction materials
[2‒8]. These complex oxides can be effectively used in
many of these application ﬁ elds only when obtained in
the highly dispersed phase. Recently, a large number of
publications have been concerned with various methods
for synthesis of these compounds in the nanosize state.
Nano- and microscopic rods, as well as nanowires and
whiskers, are obtained by high-temperature calcination
of a mixture of mechanically dispersed components and
by the method of crystallization in a melt [1, 2, 9‒11].
Rolling-up of zigzag layers into tubular structures is
observed under hydrothermal conditions, which makes
substantially larger the speciﬁ c surface area of the result-
ing material .
Russian and Indian researchers have extensively
studied the inﬂ uence exerted by various substitutions
in the octahedral framework of ceramic K
11‒14]. The effect of doping of titanate nanotubes with
cobalt on the photocatalytic activity in the reaction
of decomposition of organic compounds was studied
in . According to the results of these studies, the
substitution of titanium with cations of another valence
leads to a change in the energy gap width, shift of optical
parameters, and increase by approximately an order
of magnitude in the speciﬁ c surface area. Therefore, a
study of isomorphic substitutions in potassium titanate
nanotubes seems to be a topical task whose solution
will extend even more the opportunity for application of
materials based on alkali metal polytitanates.
The goal of our study was to examine the inﬂ uence
exerted by the crystalline state of the starting mixtures
and by parameters of the hydrothermal treatment on the
formation of potassium titanate nanotubes in substitution
of a part of titanium ions with ions of another valence
(Al, Mg, and Ni).