Development and characterization of WO3 nanoflakes for selective ethanol sensing

Spagnoli, Elena; Krik, Soufiane; Fabbri, Barbara; Valt, Matteo; Ardit, Matteo; Gaiardo, Andrea; Vanzetti, L.; Ciana, Michele Della; Cristino, Vito; Vola, Gabriele; Caramori, Stefano; Malagù, C.; Guidi, V.

doi:10.1016/j.snb.2021.130593

Cited by 31 publications

(21 citation statements)

References 80 publications

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“…Response and recovery times within minutes have been already observed for traditional SnO 2 and other materials in our previous works. 11 , 27 , 46 − 48 They were dependent on the size and geometry of the chamber and on the speed of the gas flow. 27 Since the filling time of the chamber was about 1 min 15 s, the response times of STN films should be rather fast.…”

Section: Resultsmentioning

confidence: 99%

Design of a Metal-Oxide Solid Solution for Sub-ppm H₂ Detection

et al. 2022

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Hydrogen is largely adopted in industrial processes and is one of the leading options for storing renewable energy. Due to its high explosivity, detection of H 2 has become essential for safety in industries, storage, and transportation. This work aims to design a sensing film for high-sensitivity H 2 detection. Chemoresistive gas sensors have extensively been studied for H 2 monitoring due to their good sensitivity and low cost. However, further research and development are still needed for a reliable H 2 detection at sub-ppm concentrations. Metal-oxide solid solutions represent a valuable approach for tuning the sensing properties by modifying their composition, morphology, and structure. The work started from a solid solution of Sn and Ti oxides, which is known to exhibit high sensitivity toward H 2 . Such a solid solution was empowered by the addition of Nb, which—according to earlier studies on titania films—was expected to inhibit grain growth at high temperatures, to reduce the film resistance and to impact the sensor selectivity and sensitivity. Powders were synthesized through the sol–gel technique by keeping the Sn–Ti ratio constant at the optimal value for H 2 detection with different Nb concentrations (1.5–5 atom %). Such solid solutions were thermally treated at 650 and 850 °C. The sensor based on the solid solution calcined at 650 °C and with the lowest content of Nb exhibited an extremely high sensitivity toward H 2 , paving the way for H 2 ppb detection. For comparison, the response to 50 ppm of H 2 was increased 6 times vs SnO 2 and twice that of (Sn,Ti) x O 2 .

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Section: Resultsmentioning

confidence: 99%

Design of a Metal-Oxide Solid Solution for Sub-ppm H₂ Detection

et al. 2022

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“…When the testing chamber contained a certain amount of n-butanol by injection, the chemisorbed oxygen ions and their derivatives on the surface of the sensing materials would react with the gas molecules of the n-butanol, and then caused the backdonation of the trapped electrons to the depletion layers, resulting in the decrease in the sensor resistance due to the reduction in the range of depletion region and the height of the barriers between the nanobelts [56,57]. Meanwhile, the H2O on the surface of the sensing film, When the testing chamber contained a certain amount of n-butanol by injection, the chemisorbed oxygen ions and their derivatives on the surface of the sensing materials would react with the gas molecules of the n-butanol, and then caused the backdonation of the trapped electrons to the depletion layers, resulting in the decrease in the sensor resistance due to the reduction in the range of depletion region and the height of the barriers between the nanobelts [56,57]. Meanwhile, the H 2 O on the surface of the sensing film, one of the byproducts in the reaction described above, would further decrease the resistivity of the sensor [58].…”

Section: Sensing Mechanismmentioning

confidence: 99%

Porous Pb-Doped ZnO Nanobelts with Enriched Oxygen Vacancies: Preparation and Their Chemiresistive Sensing Performance

2022

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Among various approaches to improve the sensing performance of metal oxide, the metal-doped method is perceived as effective, and has received great attention and is widely investigated. However, it is still a challenge to construct heterogeneous metal-doped metal oxide with an excellent sensing performance. In the present study, porous Pb-doped ZnO nanobelts were prepared by a simply partial cation exchange method, followed by in situ thermal oxidation. Detailed characterization confirmed that Pb was uniformly distributed on porous nanobelts. Additionally, it occupied the Zn situation, not forming its oxides. The gas-sensing measurements revealed that 0.61 at% Pb-doped ZnO porous nanobelts exhibited a selectively enhanced response with long-term stability toward n-butanol among the investigated VOCs. The relative response to 50 ppm of n-butanol was up to 47.7 at the working temperature of 300 °C. Additionally, the response time was short (about 5 s). These results were mainly ascribed to the porous nanostructure, two-dimensional belt-like morphology, enriched oxygen vacancies and the specific synergistic effect from the Pb dopant. Finally, a possible sensing mechanism of porous Pb-doped ZnO nanobelts is proposed and discussed.

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“…Metal oxide semiconductors (MOS) have special electrical conductivity, good stability, and high gas response [13][14][15]. ZnO [16][17][18], SnO 2 [19][20][21], NiO [22,23], WO 3 [24][25][26],…”

Section: Introductionmentioning

confidence: 99%

NiO-Based Gas Sensors for Ethanol Detection: Recent Progress

Zeng

2022

Journal of Sensors

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In this review, we summarized the state-of-the-art progress on the ethanol performance of NiO by means of morphology, doping, loading noble metal particles, and forming heterojunctions. We first introduced the effect of modulating NiO morphology on ethanol performance that has been reported in recent years. The morphology with large specific surface area and high porosity was considered to be the one that can bring high gas response. Then, we discussed the enhanced effect of the doping of metal cations and noble metal particle loading on the ethanol-sensitive properties of NiO. Doping ions increased the ground-state resistance and increased the oxygen defect concentration of NiO. The effects of noble metal particles on the performance of NiO included chemical sensitization and electronic sensitization. Finally, the related contents of NiO forming complexes with metal oxides and bimetallic oxides were discussed. In this section, the specific improvement mechanism was discussed first, and then, the related work of researchers in recent years was summarized. At the same time, we presented a reasonable outlook for NiO-based ethanol sensors, imagining future directions.

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Development and characterization of WO3 nanoflakes for selective ethanol sensing

Cited by 31 publications

References 80 publications

Design of a Metal-Oxide Solid Solution for Sub-ppm H₂ Detection

Design of a Metal-Oxide Solid Solution for Sub-ppm H₂ Detection

Porous Pb-Doped ZnO Nanobelts with Enriched Oxygen Vacancies: Preparation and Their Chemiresistive Sensing Performance

NiO-Based Gas Sensors for Ethanol Detection: Recent Progress

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Development and characterization of WO3 nanoflakes for selective ethanol sensing

Cited by 31 publications

References 80 publications

Design of a Metal-Oxide Solid Solution for Sub-ppm H2 Detection

Design of a Metal-Oxide Solid Solution for Sub-ppm H2 Detection

Porous Pb-Doped ZnO Nanobelts with Enriched Oxygen Vacancies: Preparation and Their Chemiresistive Sensing Performance

NiO-Based Gas Sensors for Ethanol Detection: Recent Progress

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Product

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Design of a Metal-Oxide Solid Solution for Sub-ppm H₂ Detection

Design of a Metal-Oxide Solid Solution for Sub-ppm H₂ Detection