@conference{
author = "Počuča-Nešić, Milica and Vojisavljević, Katarina and Savic, Slavica and Ribić, Vesna and Tasić, Nikola and Branković, Goran and Branković, Zorica",
year = "2019",
abstract = "In this work, two different syntheses approaches – nanocasting and sol-gel
technique were employed for the preparation of SnO2 powders for humidity sensors.
Stock solution of SnCl2 in ethanol (0.5 M) was used as a Sn-precursor for both
syntheses.
In the first procedure, this solution was infiltrated by wet impregnation method
into the hydrothermally prepared KIT-5 used as silica template. Mesoporous
SnO2/KIT-5 hybrid was obtained after two step loading/calcination process.
Calcination was performed at 550 C for 5 h. In the second procedure, silica
template was excluded from synthetic path. Ethanol solution of SnCl2 was slowly
heated to form the gel which was later submitted to the same calcination conditions
resulting in the preparation of SnO2 nanopowder.
By dispersing the as prepared powders in the ethyl-cellulose/α-terpineol
solution and adding a few drops of acetic acid in the mixture, viscous pastes were
prepared and further homogenized for 24 h with magnetic stirrer. Using doctor blade
applicator a few micron thick films were deposited onto alumina substrates provided
with interdigitated Pt/Ag electrodes.
Sensors’ characteristics were compared by measuring the change of the
complex impedance of the samples exposed to a humid climate chamber
environment at different temperatures and RH values from 40 % to 90 % at 25 °C
and from 30 % to 90 % at 50 °C. The value of impedance measured at 42 Hz and
within the RH range of 40 % to 90 %, changes 53 times at 25 °C, and 96 times at 50
°C. In contrast, for the sensor prepared from chemically derived SnO2, the
impedance changes in a moderate way – 8 times at 25 °C and 3 times at 50 °C. Fast
response/recovery time of the SnO2/KIT-5 hybrid sensor exposed to humidity
change from 40 % – 90 % at room temperature, confirmed superior potentials of this
material for humidity sensing over the SnO2.",
publisher = "Institute for Multidisciplinary Research, University of Belgrade",
journal = "5th Conference of Serbian Society for Ceramic Materials",
title = "COMPARISON OF SENSING PROPERTIES OF SnO2/KIT-5 AND SnO2 HUMIDITY SENSORS",
pages = "137-137",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_2315"
}