Enhanced acetone sensing performances of hierarchical hollow Au-loaded NiO hybrid structures (original) (raw)
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Sensors and Actuators B: Chemical, 2015
The pristine and W-doped NiO hierarchical flower-like hollow spheres were prepared by a one-step hydrothermal reaction without template and used to fabricate the gas sensors. Their gas sensing performances and possible sensitive mechanism were investigated. The results indicated that the strategy of doping W into NiO could effectively improve the gas sensing properties. The sensor based on the 4.0 at% W-doped NiO exhibited the optimal gas sensing performance, giving a ppb-level detection limit and an ultra-high response of 198.1 to 100 ppm acetone at 250 °C, which was about 139 times higher than that of the pristine NiO. The significantly enhanced sensing properties to acetone could be attributed to the changes in crystallite size, specific surface area, and hole carrier concentration caused by W doping.
Acetone sensing and modelling by low-cost NiO nanowalls
Materials Letters, 2019
NiO nanowalls were grown by low-cost chemical bath deposition (CBD) method and thermal annealing. SEM analysis showed a high surface area and porous thin film formed by a network of~20 nm thick and 270 nm tall nanosheets. NiO nanowalls were prepared onto interdigitated electrodes and applied for acetone sensing. The response transients at various temperatures were recorded an successfully modelled by two adsorption sites. Both sites are active below 250°C, while only the site with shorter response time is active above 250°C. At the optimal temperature of 250°C, the sensor demonstrated high sensitivity to acetone (1-40 ppm), a low limit of detection (LoD) of~200 ppb and good selectivity. These unique features combined with the low-cost and simple fabrication process make it a cheap and efficient acetone sensor.
Nanostructured Metal Oxide-Based Acetone Gas Sensors: A Review
Sensors
Acetone is a well-known volatile organic compound that is widely used in different industrial and domestic areas. However, it can have dangerous effects on human life and health. Thus, the realization of sensitive and selective sensors for recognition of acetone is highly important. Among different gas sensors, resistive gas sensors based on nanostructured metal oxide with high surface area, have been widely reported for successful detection of acetone gas, owing to their high sensitivity, fast dynamics, high stability, and low price. Herein, we discuss different aspects of metal oxide-based acetone gas sensors in pristine, composite, doped, and noble metal functionalized forms. Gas sensing mechanisms are also discussed. This review is an informative document for those who are working in the field of gas sensors.
High performance acetone sensor based on ZnO nanorods modified by Au nanoparticles
Journal of Alloys and Compounds, 2019
Modification with Au nanparticles on the surface of semiconductor metal oxide (SMO) is a simple and effective mean to improve the sensing performance of pristine SMO sensor. ZnO nanorods are prepared via a simple precipitation reaction and subsequently modified by catalytic Au nanoaparticles with effect on the surface through an ammonia deposition method. The gas response of sensor based on ZnO nanorods modified by Au nanoparticles is improved by 6.6 times to 100 ppm acetone at the optimal operating temperature of 172 o C, which is reduced from 219 o C for pristine ZnO sensor. Meanwhile, the response/recovery time is shortened to 1 s/ 20 s from 13 s/ 29 s. In addition, the sensing enhancement mechanism can be attributed to the electronic and chemical sensitization effects of Au nanoparticles.
Ceramics International, 2020
It is of great significance to monitor internal faults of transformer and ensure its normal and safe operation. Usually, acetylene (C 2 H 2) is considered as the characteristic gas caused by discharge failure in transformer. Using gas sensor technology to analyze dissolved gases in transformer oil is an important strategy. Recently, metal oxide semiconductor (MOS) heterojunctions with tailored microstructures have been developed to fabricate high quality gas sensors for gas detection. In this paper, hierarchical flower-like NiO/ZnO heterostructures assembled with 2D nanosheets have been synthesized by a facile hydrothermal method and calcination process. Noticeably, the introduction of different contents of NiO (3.0 at%, 5.0 at% and 10.0 at%) leads to different assembly manners of the building nanosheets into hierarchical flower-like structures, thus affecting the gas performances. Given this, a variety of microscopic characterization methods were used to observe and compare the differences in the structures and morphologies of the composites. Through the gas sensing test, it was found that the 5.0 at% NiO-modified ZnO based sensor exhibited superior sensing performances to C 2 H 2 compared with that of others. The enhanced properties may be attributed to the formation of p-n heterojunctions as well as high porosity of the nanosheets. This promising approach is versatile for the applications of high-quality gas sensors.
Acetone gas sensor based on α-Ag2WO4 nanorods obtained via a microwave-assisted hydrothermal route
Journal of Alloys and Compounds, 2016
Ag 2 WO 4 nanorod-like structures via a microwave-assisted hydrothermal method to be used as an acetone gas sensor. The nanorods showed excellent gas-sensing performance, evidenced by their sensor response and repeatability, as well as a good range of detection (0.5-20.0 ppm). The manuscript also proposes an easy and efficient way of obtaining 1-D α-Ag 2 WO 4 nanorods that exhibit remarkable acetone sensing properties.
Chemoresistive Gas Sensors for Sub-ppm Acetone Detection
Procedia Engineering, 2016
New sensors for detecting acetone directly in the exhaled breath have been developed. Several metal oxide materials, ZnO in different nano-morphologies, WO 3 pure and Zr-loaded and Ti x Sn 1-x O 2 solid solutions, have been considered for comparing the functional properties of the corresponding thick films with respect to the target gas. ZnO nano-sheets and bipyramidal nanoaggregates exhibited the large responses towards acetone, however ZnO aggregates of nanocrystals, Zr-WO 3 and Ti x Sn 1-x O 2 showed better performances as regards the influence of humidity on the acetone response.
Nitric Dioxide and Acetone Sensors Based on Iron Oxide Nanoparticles
Sensor Letters, 2013
The Fe 2 O 3 and CoFe 2 O 4 nanoparticle-based Langmuir-Blodgett films for sensing of nitric dioxide (NO 2 ) and acetone vapours have been explored. Both the sensitivity of the chemiresistors and dynamic properties, such as the response/recovery time, have been probed in dependence of the number of nanoparticle monolayers and working temperatures. The response of 23 at the NO 2 concentration of 1 ppm, i.e., approaching the canine detection limit, has been monitored implying the appropriateness for the detection of nitrate-based explosives. monolayers and thereby the controlled formation of the sensing film with targeted number of monolayers enabling to explore the effect of the film thickness on sensing properties.
2012
New medical diagnostic methods such as non-invasive breath analysis bear the potential of drastically reducing medical costs as a greater amount of automatization is possible. Here, an asymmetric electrode assembly is described that increases the SnO2sensitivity and selectivity to acetone, a tracer for diabetes type-1, and reduces the resistance of the nanostructured SnO2layer. Gold nanoparticles serving as nanoelectrodes are stochastically deposited by flame spray pyrolysis (FSP) below a functional film decreasing the effective length of the resistive components. The feasibility of this assembly is demonstrated with solid state sensors having controlled resistance and exceptionally high sensitivity and selectivity to acetone. Au nanoparticles also enable detection of acetone at relatively low temperature with still high sensor response and signal to noise ratio.