INORGANIC SYNTHESIS AND INDUSTRIAL
ISSN 1070-4272, Russian Journal of Applied Chemistry, 2014, Vol. 87, No. 8, pp. 1044−1048. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © D.S. Kalyagin, Yu.E. Ermolenko, I.E. Alekseev, E.A. Bychkov, S.A. Krotov, N.A. Mel’nikova, I.V. Murin, Yu.G. Vlasov, 2014, published
in Zhurnal Prikladnoi Khimii, 2014, Vol. 87, No. 8, pp. 1059−1063.
–TlI Chalcogenide Glasses as Perspective
Material for Solid-State Chemical Sensors
D. S. Kalyagin, Yu. E. Ermolenko, I. E. Alekseev, E. A. Bychkov, S. A. Krotov,
N. A. Mel’nikova, I. V. Murin, and Yu. G. Vlasov
Institute of Chemistry, St. Petersburg State University, Universitetskaya nab. 7–9, St. Petersburg, 199034 Russia
Received August 20, 2014
Abstract—Modern research techniques with radioactive isotopes were used to study the transport characteristics,
(conductivity and diffusion) in chalcogenide membrane materials of the Ag
–TlI system. It was
demonstrated that, on raising the silver sulﬁ de concentration in a glass, the total electrical conductivity grows
by two orders of magnitude, which is due to the pronounced change of the band structure and to the increase in
the electronic component of the conductivity. New chemical sensors for determination Tl ions in solutions were
developed on the basis of these solid-state studies.
Ecological problems and numerous tasks of techno-
logical processes require rapid determination of various
toxic metals, such as mercury [1–4], lead [5–7], cadmium
[8–10], and thallium [11–13].
The most promising for, in particular, ecological
monitoring are potentiometric [14, 15], voltammetric
, and optical sensors .
Potentiometric sensors for heavy metal ions constitute
a wide class of membrane sensors based on organic ion
exchangers , chalcogenide glasses, and crystalline
ionic conductors [19–21].
One of the main requirements imposed on a membrane
material in development of highly selective potentiomet-
ric sensors with stable and reproducible electrode func-
tions is an existence of an ionic transport of the potential-
determining ion or another ion bound to the former in the
membrane matrix. These characteristics are exhibited by
some of the materials used in sensors and, in particular, in
a number of chalcogenide glasses of various compositions
[22, 23] in which the ionic conductivity is in the range
at room temperature. Owing
to their physical and chemical properties, chalcogenide
glasses are a promising membrane material for chemical
The goal of our study was to synthesize and make a
comprehensive analysis of the transport and analytical
characteristics of chalcogenide glasses in the Ag
TlI system to determine the extent and mechanism
of the ionic transport, with the subsequent choice of
the optimal membrane composition for a new type of
thallium-selective chemical sensors.
Glasses of the Ag
–TlI system were syn-
thesized from commercial substances Ag
S and TlI of
chemically pure grade and As
obtained in the study.
Arsenic sulﬁ de was synthesized from elementary sulfur
and arsenic of special-purity grade in evacuated quartz
ampules; the weighed portion was 30 g. The synthesis
was performed in the following mode: ampules were
heated to 350°C, kept at this temperature for 1.5 h, and
then the temperature was raised to 950°C. The ampules
were kept at this temperature for 8–10 h and then were
subjected to air quenching.
Glasses of the Ag
–TlI system were synthe-
sized from the above mentioned components with 3 g of
total mass in evacuated quartz ampules.