Synergistic Effect of Surface Acidity and PtO Catalyst on the Sensitivity of Nanosized Metal-Oxide Semiconductors to Benzene.

Benzene is a potentially carcinogenic volatile organic compound (VOC) and its vapor must be strictly monitored in air. Metal-oxide semiconductors (MOS) functionalized by catalytic noble metals are promising materials for sensing VOC, but basic understanding of the relationships of materials composition and sensors behavior should be improved. In this work, the sensitivity to benzene was comparatively studied for nanocrystalline -type MOS (ZnO, InO, SnO, TiO, and WO) in pristine form and modified by catalytic PtO nanoparticles.

GaO(Sn) Oxides for High-Temperature Gas Sensors.

Gallium(III) oxide is a promising functional wide-gap semiconductor for high temperature gas sensors of the resistive type. Doping of GaO with tin improves material conductivity and leads to the complicated influence on phase content, microstructure, adsorption sites, donor centers and, as a result, gas sensor properties. In this work, GaO and GaO(Sn) samples with tin content of 0-13 at.

The Key Role of Active Sites in the Development of Selective Metal Oxide Sensor Materials.

Development of sensor materials based on metal oxide semiconductors (MOS) for selective gas sensors is challenging for the tasks of air quality monitoring, early fire detection, gas leaks search, breath analysis, etc. An extensive range of sensor materials has been elaborated, but no consistent guidelines can be found for choosing a material composition targeting the selective detection of specific gases. Fundamental relations between material composition and sensing behavior have not been unambiguously established.

Effect of Humidity on Light-Activated NO and NO Gas Sensing by Hybrid Materials.

Air humidity is one of the main factors affecting the characteristics of semiconductor gas sensors, especially at low measurement temperatures. In this work we analyzed the influence of relative humidity on sensor properties of the hybrid materials based on the nanocrystalline SnO and InO and Ru (II) heterocyclic complex and verified the possibility of using such materials for NO (0.25-4.

Nanocomposites SnO/SiO:SiO Impact on the Active Centers and Conductivity Mechanism.

This paper is focused on the effect of the stabilizing component SiO on the type and concentration of active sites in SnO/SiO nanocomposites compared with nanocrystalline SnO. Previously, we found that SnO/SiO nanocomposites show better sensor characteristics in CO detection (lower detection limit, higher sensor response, and shorter response time) compared to pure SnO in humid air conditions. Nanocomposites SnO/SiO synthesized using the hydrothermal method were characterized by low temperature nitrogen adsorption, XRD, energy dispersive X-ray spectroscopy (EDX), thermo-programmed reduction with hydrogen (TPR-H), IR-, and electron-paramagnetic resonance (EPR)-spectroscopy methods.

Quasi Similar Routes of NO and NO Sensing by Nanocrystalline WO: Evidence by In Situ DRIFT Spectroscopy.

Tungsten oxide is a renowned material for resistive type gas sensors with high sensitivity to nitrogen oxides. Most studies have been focused on sensing applications of WO for the detection of NO and a sensing mechanism has been established. However, less is known about NO sensing routes.

Sub-ppm Formaldehyde Detection by - TiO@SnO Nanocomposites.

Formaldehyde (HCHO) is an important indicator of indoor air quality and one of the markers for detecting lung cancer. Both medical and air quality applications require the detection of formaldehyde in the sub-ppm range. Nanocomposites SnO/TiO are promising candidates for HCHO detection, both in dark conditions and under UV illumination.

Enhancement of Lewis Acidity of Cr-Doped Nanocrystalline SnO : Effect on Surface NH Oxidation and Sensory Detection Pattern.

Understanding ammonia oxidation over metal oxide surfaces is crucial for improving its detection with resistive type gas sensors. Formation of NO during this process makes sensor response and calibration unstable. Cr-doping of nanocrystalline metal oxides has been reported to suppress NO sensitivity and improve response towards NH , however the exact mechanism of such chromium action remained unknown.

Nanocomposites SnO₂/SiO₂ for CO Gas Sensors: Microstructure and Reactivity in the Interaction with the Gas Phase.

Nanocomposites SnO₂/SiO₂ with a silicon content of [Si]/([Sn] + [Si]) = 3/86 mol.% were obtained by the hydrothermal method. The composition and microstructure of the samples were characterized by EDX, XRD, HRTEM and single-point Brunauer-Emmet-Teller (BET) methods.

Nanocrystalline BaSnO₃ as an Alternative Gas Sensor Material: Surface Reactivity and High Sensitivity to SO₂.

Nanocrystalline perovskite-type BaSnO₃ was obtained via microwave-assisted hydrothermal route followed by annealing at variable temperature. The samples composition and microstructure were characterized. Particle size of 18-23 nm was unaffected by heat treatment at 275-700 °C.