Pd-Loaded In2O3 Hollow Spheres with Enhanced Formaldehyde Sensing at Low Temperature

The porous Pd-loaded In2O3 hollow spheres were successfully prepared by simple one-step method with the template of carbon spheres. The effect of calcination temperatures on morphology, composition and gas sensing performance of the as-obtained products was discussed by a series of test methods. The sample calcined at 550∘C showed uniform porous hollow spheres with an average diameter of 100[Formula: see text]nm. Gas-sensing results exhibited that the Pd-In2O3 hollow spheres-based sensor possessed excellent sensing properties to formaldehyde, which include high response value (33), low working temperature (180∘C) and fast response and recovery time (12[Formula: see text]s and 22[Formula: see text]s). The enhanced HCHO-sensing properties of Pd-In2O3 composites were attributed to the special porous and hollow structure, abundant oxygen vacancies and the catalysis of palladium. Pd-loaded In2O3 hollow spheres had been proved to be an ideal material for detecting HCHO at a low working temperature.

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Fast Response Isopropanol Sensing Properties with Sintered BiFeO3 Nanocrystals

Materials ◽

10.3390/ma13173829 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3829 ◽

Cited By ~ 1

Author(s):

Hongxiang Xu ◽

Junhua Xu ◽

Junlin Wei ◽

Yamei Zhang

Keyword(s):

Gas Sensing ◽

Fast Response ◽

Gas Detection ◽

Detection Range ◽

Sensing Properties ◽

Working Temperature ◽

Sensing Material ◽

Gas Sensing Properties ◽

Response And Recovery ◽

Optimum Working

BiFeO3 nanocrystals were applied as the sensing material to isopropanol. The isopropanol sensor based on BiFeO3 nanocrystals shows excellent gas-sensing properties at the optimum working temperature of 240 °C. The sensitivity of as-prepared sensor to 100 ppm isopropanol is 31 and its response and recovery time is as fast as 6 and 17 s. The logarithmic curves of the sensitivity and concentration of BiFeO3 sensors are a very good linear in the low detection range of 2–100 ppm. In addition, the gas sensing mechanism is also discussed. The results suggest that the BiFeO3 nanomaterial can be potentially applied in isopropanol gas detection.

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Hierarchical Nanoheterostructure of Tungsten Disulfide Nanoflowers Doped with Zinc Oxide Hollow Spheres: Benzene Gas Sensing Properties and First-Principles Study

ACS Applied Materials & Interfaces ◽

10.1021/acsami.9b07021 ◽

2019 ◽

Vol 11 (34) ◽

pp. 31245-31256 ◽

Cited By ~ 25

Author(s):

Dongzhi Zhang ◽

Junfeng Wu ◽

Peng Li ◽

Yuhua Cao ◽

Zhimin Yang

Keyword(s):

Zinc Oxide ◽

First Principles ◽

Gas Sensing ◽

Hollow Spheres ◽

Tungsten Disulfide ◽

Sensing Properties ◽

First Principles Study ◽

Gas Sensing Properties

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Preparation of Nanostructured SnO2-NiO Composite Semiconductor for Gas Sensor Applications

International Journal of Advanced Research in Science, Communication and Technology ◽

10.48175/ijarsct-2134 ◽

2021 ◽

pp. 391-403

Author(s):

S. Kumar ◽

P. Gowthaman ◽

J. Deenathayalan

Keyword(s):

Gas Sensor ◽

Composite Nanofibers ◽

Volume Fraction ◽

Gas Sensing ◽

Precipitation Method ◽

Response Sensitivity ◽

X Ray ◽

Sensing Properties ◽

Working Temperature ◽

Gas Sensing Properties

Electro spinning technology combined with chemical precipitation method and high-temperature calcination was used to prepare SnO2-NiO composite semiconductor nanofibers with different Sn content. Scanning electron microscope (SEM), X-ray diffractometer (XRD) and energy dispersive X-ray spectrometer (EDS) were used to characterize the morphology, structure and content of various elements of the sample. Using ethanol as the target gas, the gas sensing properties of SnO2-NiO nanofibers and the influence of Sn content on the gas sensing properties of composite nanofibers were explored. The research results show that SnO2-NiO composite nanofibers have a three-dimensional network structure, and the SnO2 composite can significantly enhance the gas sensitivity of NiO nanofibers. With increase of SnO2 content, the response sensitivity of composite fibers to ethanol gas increases, and the response sensitivity of composite nanofibers with the highest response to ethanol gas with a volume fraction of 100×10-6 at the optimal working temperature of 160℃ are13.4;It is 8.38 times the maximum response sensitivity of NiO nanofibers. Compared with the common ethanol gas sensor MQ-3 on the market, SnO2-NiO composite nanofibers have a lower optimal working temperature and higher response sensitivity, which has certain practical application value

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A Review of Carbon Nanotubes-Based Gas Sensors

Journal of Sensors ◽

10.1155/2009/493904 ◽

2009 ◽

Vol 2009 ◽

pp. 1-24 ◽

Cited By ~ 255

Author(s):

Yun Wang ◽

John T. W. Yeow

Keyword(s):

Carbon Nanotubes ◽

Gas Sensors ◽

Gas Sensing ◽

Low Cost ◽

High Surface ◽

Hollow Structure ◽

Volume Ratio ◽

Fast Response ◽

Sensing Technology ◽

Structure Of Nanomaterials

Gas sensors have attracted intensive research interest due to the demand of sensitive, fast response, and stable sensors for industry, environmental monitoring, biomedicine, and so forth. The development of nanotechnology has created huge potential to build highly sensitive, low cost, portable sensors with low power consumption. The extremely high surface-to-volume ratio and hollow structure of nanomaterials is ideal for the adsorption of gas molecules. Particularly, the advent of carbon nanotubes (CNTs) has fuelled the inventions of gas sensors that exploit CNTs' unique geometry, morphology, and material properties. Upon exposure to certain gases, the changes in CNTs' properties can be detected by various methods. Therefore, CNTs-based gas sensors and their mechanisms have been widely studied recently. In this paper, a broad but yet in-depth survey of current CNTs-based gas sensing technology is presented. Both experimental works and theoretical simulations are reviewed. The design, fabrication, and the sensing mechanisms of the CNTs-based gas sensors are discussed. The challenges and perspectives of the research are also addressed in this review.

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A Two‐Step Method Synthesis and Gas Sensing Properties of CoSnO 3 Nanoparticles

ChemistrySelect ◽

10.1002/slct.201901631 ◽

2019 ◽

Vol 4 (25) ◽

pp. 7591-7595 ◽

Cited By ~ 1

Author(s):

Ting Li ◽

Zhidong Lin ◽

Ping Fu ◽

Shenggao Wang ◽

Zhe Chen ◽

...

Keyword(s):

Gas Sensing ◽

Step Method ◽

Sensing Properties ◽

Gas Sensing Properties

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Excellent Gas Sensing of CdS Nanowires Decorated with Ag Nanoparticles

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2019.16720 ◽

2019 ◽

Vol 19 (11) ◽

pp. 7083-7088 ◽

Cited By ~ 1

Author(s):

Nan Zhang ◽

Xiaohui Ma ◽

Shengping Ruan ◽

Yanyang Yin ◽

Chuannan Li ◽

...

Keyword(s):

Relative Humidity ◽

Ag Nanoparticles ◽

Gas Sensing ◽

Average Diameter ◽

Sensing Properties ◽

Gas Sensing Properties ◽

Cds Nanowires ◽

The Stability ◽

Ethanol Sensing ◽

The One

In this study, CdS nanowires (NWs)/Ag nanoparticle materials (CdS@Ag) with Schottky junction were synthesized by a simple process. The Ag nanoparticles with a diameter of 3–10 nm were uniformly scattered on the surface of CdS NWs with an average diameter of 30 nm. The gas sensing properties and the effect of Ag content and relative humidity on the ethanol sensing properties of CdS NWs were investigated in detail. When the relative humidity was below 60% RH, the sensor, especially the one based on [email protected], exhibited an enhanced ethanol sensing response and selectivity compared with that of pristine CdS NWs, which was believed that Ag catalyzed the reaction between ionized oxygen species and ethanol. However, excessive Ag content does not mean a higher response and even decreased the response. Also, the stability of CdS NWs and CdS@Ag NWs was also investigated, which were almost stable for four months.

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Effects of Preparing Conditions on NO2-Sensing Properties of Sputtered WO3 Nano-Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.1680 ◽

2013 ◽

Vol 690-693 ◽

pp. 1680-1684

Author(s):

Feng Yun Sun ◽

Ming Hu ◽

Peng Sun

Keyword(s):

Gas Sensing ◽

High Sensitivity ◽

Fast Response ◽

Optimal Parameters ◽

Working Pressure ◽

Sensing Properties ◽

Dc Reactive Magnetron Sputtering ◽

Experiment Method ◽

Discharge Gas ◽

Gas Ratio

WO3 nano-films were deposited on Al2O3 substrate by dc reactive magnetron sputtering method. The effects of preparing conditions, such as the discharge gas ratio (Ar:O2), working pressure, sputtering time and annealing temperature on microstructure, crystalline state and NO2-sensing properties of WO3 nano-films were investigated by orthogonal trial experiment method. The optimum technological conditions were determined by orthogonal test and extreme difference analysis. The crystallization, morphology and composition of WO3 thin film obtained at the optimal parameters were studied by XRD, SEM and XPS. The gas sensing mechanism was also studied. WO3 nano-film shows high sensitivity, fast response, good selectivity at the best operating temperature 200°C.

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MOFs-Derived Porous NiFe2O4 Nano-Octahedrons with Hollow Interiors for an Excellent Toluene Gas Sensor

Nanomaterials ◽

10.3390/nano9081059 ◽

2019 ◽

Vol 9 (8) ◽

pp. 1059 ◽

Cited By ~ 4

Author(s):

Yanlin Zhang ◽

Chaowei Jia ◽

Qiuyue Wang ◽

Quan Kong ◽

Gang Chen ◽

...

Keyword(s):

Gas Sensing ◽

Metal Organic Framework ◽

Fast Response ◽

Sensing Properties ◽

Gas Sensing Properties ◽

Metal Organic ◽

Response And Recovery ◽

Nife2o4 Nanoparticles ◽

Gas Molecules ◽

Ppm Level

Toluene is extensively used in many industrial products, which needs to be effectively detected by sensitive gas sensors even at low-ppm-level concentrations. Here, NiFe2O4 nano-octahedrons were calcinated from NiFe-bimetallic metal-organic framework (MOFs) octahedrons synthesized by a facile refluxing method. The co-existence of p-Phthalic acid (PTA) and 3,3-diaminobenzidine (DAB) promotes the formation of smooth NiFe-bimetallic MOFs octahedrons. After subsequent thermal treatment, a big weight loss (about 85%) transformed NiFe2O4 nanoparticles (30 nm) into NiFe2O4 porous nano-octahedrons with hollow interiors. The NiFe2O4 nano-octahedron based sensor exhibited excellent gas sensing properties for toluene with a nice stability, fast response, and recovery time (25 s/40 s to 100 ppm toluene), and a lower detection limitation (1 ppm) at 260 °C. The excellent toluene-sensing properties can not only be derived from the hollow interiors combined with porous nano-octahedrons to favor the diffusion of gas molecules, but also from the efficient catalytic activity of NiFe2O4 nanoparticles.

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