Monoelectrode gas sensors based on SnO2 semiconductor ceramics

The Ti wire functionalized with inherent TiO2 nanotubes by anodization as one-electrode gas sensor: A proof-of-concept study

“…For example, we have drawn the dependence of gas response of Ti-TiO2 NT wire, 60 h of anodization, on analyte concentrations in Figure 9. All the curves follow a linear function which is an inherent advantage of one-electrode sensors in agreement with other reports dealing with SnO2 [27,28] and In2O3 [29,30] sensing materials. The observed differences in the response to different analytes could relate to surface chemistry (receptor function) and reflect an exchange between local states in the gap and conductance band of TiO2 as well as to free carrier diffusion along/into the mesonanoporous oxide layer (transduction function).…”

In2O3:Ga and In2O3:P-based one-electrode gas sensors: Comparative study

“…At the present, metal oxides such as SnO 2 , In 2 O 3 , WO 3 and ZnO were tested for the one-electrode gas sensors design [4]. However, experiment has shown that In 2 O 3 , due to specific electrophysical properties, is the most promising material for such application [3][4][5]. The most studied metal oxide SnO 2 [6] is not the optimal material for oneelectrode gas sensor design due to much higher resistance [7].…”

Selectivity of Ti-doped In2O3 ceramics as an ammonia sensor

“…These compounds were characterized by weak paramagnetism. The differences in electronic structure of NH 3 , H 2 and CO should lead to the different adsorption and activation behaviors of these molecules. Thus, it was supposed that the largest response to NH 3 achieved with 1.0 mol% Ti 4+ -In 2 O 3 was intimately related to molecule structure holding a lone pair of electrons.…”

“…In 2 O 3 can be used as a material of ammonia sensors, but the major problem associated with In 2 O 3 is its crosssensitivity, as encountered with most oxide semiconductor sensors. As NH 3 and CO than to NH 3 [3]. The literature reported that the main cause of the low sensitivity to NH 3 is the competitive occurrence of two reactions during the NH 3 oxidation on the sensor surface; consumption of chemisorbed oxygen and chemisorption of negatively charged NO x species (especially NO 2 ) as the oxidation products of NH 3 [4].…”