The Room-Temperature Chemiresistive Properties of Potassium Titanate Whiskers versus Organic Vapors

Abstract

The development of portable gas-sensing units implies a special care of their power efficiency, which is often approached by operation at room temperature. This issue primarily appeals to a choice of suitable materials whose functional properties are sensitive toward gas vapors at these conditions. While the gas sensitivity is nowadays advanced by employing the materials at nano-dimensional domain, the room temperature operation might be targeted via the application of layered solid-state electrolytes, like titanates. Here, we report gas-sensitive properties of potassium titanate whiskers, which are placed over a multielectrode chip by drop casting from suspension to yield a matrix mono-layer of varied density. The material synthesis conditions are straightforward both to get stable single-crystalline quasi-one-dimensional whiskers with a great extent of potassium replacement and to favor the increase of specific surface area of the structures. The whisker layer is found to be sensitive towards volatile organic compounds (ethanol, isopropanol, acetone) in the mixture with air at room temperature. The vapor identification is obtained via processing the vector signal generated by sensor array of the multielectrode chip with the help of pattern recognition algorithms.

Quasi-2D Co3O4 nanoflakes as an efficient gas sensor versus alcohol VOCs

“…When deposited on the Au electrode the material represents a rather dense though porous film comprised of interconnected flakes (Figure 1c) architecture which is favorable for gas sensor development due to high surface-to-volume ratio. Therefore, we have applied the same approach to the deposition of cobalt oxide on Si substrate equipped with multiple Pt strips 59 to develop gas-sensitive layers. In preliminary studies, we have not found large differences in the morphology of cobalt oxide when employing the same protocols for deposition at Pt electrodes.…”

Effect of Voltage on Gas Sensor Performance of Anodization Synthesized TiO2 Nanotubes Arrays

“…In the reaction, the increased charge carriers on semiconductor surfaces will reduce the thickness of the depletion layer there, which will subsequently cause the resistance of the semiconductor to drop [24]. Importantly, the major interest is in discovering options for operating sensors at low temperatures (room temperature) without losing elevated sensing capacity [25,26]. Nonetheless, the sensitivities of their gas are frequently only obtained at high temperatures, resulting in low durability and high energy consumption [27].…”

Light-Tuned DC Conductance of Anatase TiO2 Nanotubular Arrays: Features of Long-Range Charge Transport

“…Recently, peculiarities of the generation of carriers and their transfer found a great interest in the chemical sensing where light irradiation could particularly reduce the energy consumption by gas sensors [ 17 , 18 , 19 ]. The primary interest is to find options for the sensor operation at room temperature without a loss in high sensing capacity [ 20 , 21 , 22 ]. Here, the simplest way to create a chemiresistive layer between the flat metal electrodes is sedimentation of oxide nanostructures over the inter-electrode gap.…”