Synthesis of Au Nanoparticles Functionalized 1D α-MoO3 Nanobelts and Their Gas Sensing Properties

NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850115 ◽  
Author(s):  
Liwei Wang ◽  
Shaopeng Wang ◽  
Hao Fu ◽  
Yinghui Wang ◽  
Kefu Yu
Keyword(s):  
Electron Microscope ◽  
Au Nanoparticles ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Molecular Probe ◽  
Optimal Operating ◽  
Au Nps ◽  
X Ray ◽  
Sensing Properties ◽  
Optimal Operating Temperature

A novel sensor material of Au nanoparticles (NPs) functionalized 1D [Formula: see text]-MoO3 nanobelts (NBs) was fabricated by a facile lysine-assisted approach. The obtained Au/[Formula: see text]-MoO3 product was characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive X-ray (EDX), and X-ray photoelectron spectra (XPS). Then, in order to investigate the gas sensing performances of our samples, a comparative gas sensing study was carried out on both the [Formula: see text]-MoO3 NBs before and after Au NPs decoration by using ethanol vapor as the molecular probe. The results turned out that, after the functionalization of Au NPs, the sensor exhibited improved gas-sensing characteristics than the pure [Formula: see text]-MoO3, such as response and recovery time, optimal operating temperature (OT) and excellent selectivity. Take for example 200[Formula: see text]ppm of ethanol, the response/recovery times were 34[Formula: see text]s/43[Formula: see text]s and 5.7[Formula: see text]s/10.5[Formula: see text]s, respectively, while the optimal operating temperature (OT) was lower to 200[Formula: see text]C rather than 250[Formula: see text]C. Besides, the functionalized sensor showed a higher response to ethanol at 200[Formula: see text]C, and response was 1.6 times higher than the pure MoO3. The mechanism of such improved sensing properties was interpreted, which might be attributed to the spillover effect of Au NPs and the electronic metal-support interaction.

scholarly journals Effects of Niobium-Loading on Sulfur Dioxide Gas-Sensing Characteristics of Hydrothermally Prepared Tungsten Oxide Thick Film

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Viruntachar Kruefu ◽  
Anurat Wisitsoraat ◽  
Sukon Phanichphant
Keyword(s):  
Spin Coating ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sensor Response ◽  
X Ray Diffraction ◽  
Optimal Operating ◽  
Impregnation Process ◽  
X Ray ◽  
Transmission Electron ◽  
Sensing Characteristics

Nb-loaded hexagonal WO3nanorods with 0–1.0 wt% loading levels were successfully synthesized by a simple hydrothermal and impregnation process and characterized for SO2sensing. Nb-loaded WO3sensing films were produced by spin coating on alumina substrate with interdigitated gold electrodes and annealed at 450°C for 3 h in air. Structural characterization by X-ray diffraction, high-resolution transmission electron microscopy, and Brunauer-Emmett-Teller analysis showed that spherical, oval, and rod-like Nb nanoparticles with 5–15 nm mean diameter were uniformly dispersed on hexagonal WO3nanorods with 50–250 nm diameter and 100 nm–5 µm length. It was found that the optimal Nb loading level of 0.5 wt% provides substantial enhancement of SO2response but the response became deteriorated at lower and higher loading levels. The 0.50 wt% Nb-loaded WO3nanorod sensing film exhibits the best SO2sensing performances with a high sensor response of ~10 and a short response time of ~6 seconds to 500 ppm of SO2at a relatively low optimal operating temperature of 250°C. Therefore, Nb loading is an effective mean to improve the SO2gas-sensing performances of hydrothermally prepared WO3nanorods.

scholarly journals Acetone Gas Sensing Properties of a Multiple-Networked Fe2O3-Functionalized CuO Nanorod Sensor

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Sunghoon Park ◽  
Hyejoon Kheel ◽  
Gun-Joo Sun ◽  
Taegyung Ko ◽  
Wan In Lee ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Optimal Operating ◽  
Sensing Properties ◽  
Adsorption Sites ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Cuo Nanorods ◽  
Sensing Performance

Fe2O3-decorated CuO nanorods were prepared by Cu thermal oxidation followed by Fe2O3decoration via a solvothermal route. The acetone gas sensing properties of multiple-networked pristine and Fe2O3-decorated CuO nanorod sensors were examined. The optimal operating temperature of the sensors was found to be 240°C. The pristine and Fe2O3-decorated CuO nanorod sensors showed responses of 586 and 1,090%, respectively, to 1,000 ppm of acetone at 240°C. The Fe2O3-decorated CuO nanorod sensor also showed faster response and recovery than the latter sensor. The acetone gas sensing mechanism of the Fe2O3-decorated CuO nanorod sensor is discussed in detail. The origin of the enhanced sensing performance of the multiple-networked Fe2O3-decorated CuO nanorod sensor to acetone gas was explained by modulation of the potential barrier at the Fe2O3-CuO interface, highly catalytic activity of Fe2O3for acetone oxidation, and the creation of active adsorption sites by Fe2O3nanoparticles.

Simple Synthesis of Mesoporous SnO2 Microspheres and their Gas Sensing Properties

2014 ◽  
Vol 1044-1045 ◽  
pp. 96-99
Author(s):  
Zhi Peng Sun ◽  
Yi Lu
Keyword(s):  
Electron Microscope ◽  
Gas Sensing ◽  
Resorcinol Formaldehyde ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Sensitivity And Selectivity ◽  
20 Nm ◽  
Tin Tetrachloride

In this work, uniform mesoporous SnO2microspheres have been prepared via a facile and scalable method using tin tetrachloride pentahydrate (SnCl4·5H2O) and resorcinol-formaldehyde gel (RF gel) as starting materials. Furthermore, the structure and morphology of the as-prepared product were characterized by scanning electron microscope (SEM), Transmission electron microscope (TEM) and X-ray diffractometer (XRD). The results revealed that as-synthesized microspheres were around 500 nm in size and composed of large amount of SnO2nanoparticles with diameters of 10-20 nm. Gas sensors based on mesoporous SnO2microspheres were fabricated, and their gas sensing properties were tested for response to methane, butane, H2and CO gas. The sensor exhibited better sensitivity and selectivity to H2vapors at 300 °C than that of the conventional SnO2materials. The enhancement in gas sensing properties was attributed to their unique nanostructures.

Decoration of Gold Nanoparticles on TiO2 Thin Films for Enhanced Response of Ethanol Gas Sensors

2014 ◽  
Vol 979 ◽  
pp. 251-254 ◽  
Author(s):  
Benjarong Samransuksamer ◽  
Mati Horprathum ◽  
Pitak Eiamchai ◽  
Viyapol Patthanasettakul ◽  
Anurat Wisitsoraat ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensors ◽  
Au Nanoparticles ◽  
Operating Temperature ◽  
Element Composition ◽  
Dc Magnetron Sputtering ◽  
Au Nps ◽  
X Ray ◽  
Gas Concentration ◽  
Average Size

This work investigated the decoration of the gold (Au) nanoparticles (NPs) on the TiO2 thin films for the applications in ethanol gas sensors. The Au-decorated TiO2 thin films (Au-TiO2) were prepared by the DC magnetron sputtering on the silicon (100) wafers and alumina substrates, interdigitated with Au electrodes. The distribution and size of Au nanoparticles were controlled by varying the sputtering time. Morphologies and element composition of the Au-TiO2 films were examined by field-emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX) respectively. The FE-SEM micrographs when the sputtering time was increased, the average size of the Au NPs was also increased. On the other hand, the distribution of the Au NPs was decreased. The change in size and distribution of the Au NPs consequently improved the response of ethanol gas sensors. The prepared Au-TiO2 was tested, in comparison with TiO2 reference films, as the ethanol sensors at 250-350oC in 50-1,000 ppm gas concentration. The results showed that the TiO2 thin film with Au-decorated at 6 sec sputtering time yielded the highest response of 514 at 350oC operating temperature and 1,000 ppm gas concentration.

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

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

A Novel Tungsten Trioxide Based Gas Sensor for Indoor Formaldehyde Detection

2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Material ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Gas Response

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.

TUNGSTEN-DOPED TiO2 NANOLAYERS WITH IMPROVED CO2 GAS SENSING PROPERTIES FOR ENVIRONMENTAL APPLICATIONS

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850024 ◽  
Author(s):  
MALIHEH SABERI ◽  
ALI AKBAR ASHKARRAN
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sol Gel ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Vis Spectroscopy ◽  
Gas Sensing Properties ◽  
Tungsten Concentration

Tungsten-doped TiO2 gas sensors were successfully synthesized using sol–gel process and spin coating technique. The fabricated sensor was characterized by field emission scanning electron microscopy (FE-SEM), ultraviolet visible (UV–Vis) spectroscopy, transmission electron microscopy (TEM), X-Ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Gas sensing properties of pristine and tungsten-doped TiO2 nanolayers (NLs) were probed by detection of CO2 gas. A series of experiments were conducted in order to find the optimum operating temperature of the prepared sensors and also the optimum value of tungsten concentration in TiO2 matrix. It was found that introducing tungsten into the TiO2 matrix enhanced the gas sensing performance. The maximum response was found to be (1.37) for 0.001[Formula: see text]g tungsten-doped TiO2 NLs at 200[Formula: see text]C as an optimum operating temperature.

In situ growth of WO3 nanotube arrays and their H2S gas sensing properties for reduced operating temperature

2020 ◽  
Vol 271 ◽  
pp. 127716
Author(s):  
Xiaoguang San ◽  
Yiming Lu ◽  
Guosheng Wang ◽  
Dan Meng ◽  
Xiaohui Gong ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Operating Temperature ◽  
Nanotube Arrays ◽  
In Situ Growth ◽  
Sensing Properties ◽  
Gas Sensing Properties
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