Detection of hydrogen peroxide vapor using flexible gas sensor based on SnO₂ nanoparticles decorated with multi-walled carbon nanotubes

Abstract

In this work, a high-sensitive flexible sensor based on the SnO2 nanoparticles decorated with the multi-walled carbon nanotubes (MWCNTs) was fabricated by a simple and cost-effective centrifugation method for hydrogen peroxide vapour (HPV) detection. Morphological, composition, structural, and HPV sensing studies of the film were thoroughly conducted. Scanning electron microscopy (SEM) revealed the presence of MWCNTs in the SnO2 material and energy dispersive x-ray (EDX) elementary analysis determined the actual concentration of carbon elements (24.47 wt%) in the SnO2:MWCNTs material with pronounced peaks of C, O, and Sn. Elemental mapping analysis showed the nearly homogeneous distribution of the elements while x-ray diffraction analysis (XRD) confirmed the diffraction peaks of tin oxide and carbon. The HPV sensing behaviour of the flexible SnO2:MWCNTs sensor was investigated in the temperature range of 25 °C–150 °C towards 1.5–56 ppm HPV under ultraviolet (UV) irradiation. The flexible sensor had a fairly high response (44) to 1.5 ppm of HPV concentration at room temperature (RT). The fabricated SnO2:MWCNTs based sensor was capable of detecting extremely low concentrations of HPV, thus being a potential candidate for use in real environments.

MWCNTs/Fe2O3:ZnO Nanocomposite Material for Chemoresistive Sensing of Hydrogen Peroxide Vapors

“…These processes can be represented by the following supposed reactions. 19,30 2H O 2H O 2 2(gas) 2 2(ads)…”

“…In the case of providing the necessary activation energies (for the temperature range of 100–150 °C) for the MWCNTs/Fe 2 O 3 :ZnO sensor, the hydrogen peroxide molecule tends to dissociate, leading to the formation of molecules of water (H 2 O) and oxygen (O 2 ). These processes can be represented by the following supposed reactions. , 2 H 2 O 2 ( gas ) ↔ 2 H 2 O 2 ( ads ) 2 H 2 O 2 → 2 H 2 normalO + O 2 O 2 + e − → O 2 − …”

“…It exhibited a high response to 10 ppm of the NO 2 concentration at room temperature. Thus, the introduction of CNTs and multiwall carbon nanotubes (MWCNTs) into the main metal oxide sensing matrix as dopants or the use of their composites simultaneously improves the time stability of the sensitive material, increases the sensor speed, lowers the operating temperature, and reduces the minimum detection limit. − …”

Acetone Vapors Detection Using a MWCNTs/SnO2 Nanocomposite Material

“…A further increase in temperature up to 300 °C accompanied by a more than 43 times decrease in response (Figure a). This is mainly caused by the rate of desorption exceeding that of adsorption at the higher temperatures, where the target gas molecules reaching the active surface do not have time to react chemically with the semiconductor but are immediately desorbed. , Thus, an operating temperature of 250 °C was chosen as the most effective point for the sensor’s actual performance. The dynamic response curves of the sensor for the acetone concentration range of 1–400 ppm are shown in Figure b, which are distinguished by a clear representation of the edges of the response and recovery curves over time.…”

“…In the case of higher concentrations, since the gas molecules diffuse into the deeper parts of the film, it takes a long time for their desorption. 33 The temporal stability of the sensor response over 10 days was also investigated as the best indicator of the sensor's longterm application. Response measurements were carried out under absolutely identical conditions on each day toward 400 ppm acetone vapor at 250 °C (Figure 10b).…”