scholarly journals Enhanced Humidity Sensing Response of SnO2/Silicon Nanopillar Array by UV Irradiation

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2141 ◽  
Author(s):  
Wei Li ◽  
Linlin Wang ◽  
Yun Cai ◽  
Peifeng Pan ◽  
Jinze Li ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Response Time ◽  
Specific Surface ◽  
Uv Irradiation ◽  
Recovery Time ◽  
Room Temperature ◽  
Uv Light ◽  
Humidity Sensing ◽  
Potential Applications ◽  
Humidity Sensitivity

In this work, a silicon nanopillar array was created with nanosphere lithography. SnO2 film was deposited on this nanostructure by magnetron sputtering to form an SnO2/silicon nanopillar array sensor. The humidity sensitivity, response time, and recovery time were all measured at room temperature (25 °C) with UV or without UV irradiation. As a result, the humidity sensitivity properties were improved by enlarging the specific surface area with ordered nanopillars and irradiating with UV light. These results indicate that nanostructure sensors have potential applications in the field of sensors.

Fabrication, structural and humidity sensing properties of BaTiO3 nanofibers via electrospinning

2015 ◽  
Vol 29 (12) ◽  
pp. 1550066 ◽  
Author(s):  
Chen-Hao Sheng ◽  
Hong-Di Zhang ◽  
Shuai Chen ◽  
Jun-Cheng Zhang ◽  
Wen-Peng Han ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Recovery Time ◽  
Room Temperature ◽  
Electrospinning Technique ◽  
Humidity Sensing ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Humidity Sensitivity ◽  
Humidity Sensing Properties

Barium titanate (BTO) nanofibers were synthesized by electrospinning and followed calcination. The morphologies and microstructures of the nanofibers were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Calcinating temperature and process greatly influenced the surface morphology of the nanofibers. In addition, parallel BTO nanofibers were also successfully produced by a centrifugal electrospinning technique. And the humidity sensing properties of the nanofibers were measured. The results showed an ultrafast response time (~0.5 s) and a recovery time (~0.4 s) to humidity at room temperature, which revealed excellent humidity sensitivity performance.

scholarly journals Zn Doped α-Fe2O3: An Efficient Material for UV Driven Photocatalysis and Electrical Conductivity

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 273 ◽  
Author(s):  
Suman ◽  
Surjeet Chahal ◽  
Ashok Kumar ◽  
Parmod Kumar
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Uv Light ◽  
Sol Gel ◽  
High Energy ◽  
Lattice Parameter ◽  
Dielectric Behavior ◽  
Energy Storage Devices ◽  
Vis Spectroscopy ◽  
Potential Applications

Zinc (Zn) doped hematite (α-Fe2O3) nanoparticles with varying concentrations (pure, 2%, 4% and 6%) were synthesized via sol-gel method. The influence of divalent Zn ions on structural, optical and dielectric behavior of hematite were studied. X-ray diffraction (XRD) pattern of synthesized samples were indexed to rhombohedral R3c space group of hematite with 14–21 nm crystallite size. The lattice parameter (a and c) values increase upto Zn 4% and decrease afterwards. The surface morphology of prepared nanoparticles were explored using transmission electron microscopy (TEM). The band gap measured from Tauc’s plot, using UV-Vis spectroscopy, showed reduction in its values upto Zn 4% and the reverse trend was obtained in higher concentrations. The dielectric properties of pure and Zn doped hematite were investigated at room temperature and followed the same trends as that of XRD parameters and band gap. Photocatalytic properties of nanoparticles were performed for hazardous Rose bengal dye and showed effective degradation in the presence of UV light. Hence, Zn2+ doped hematite can be considered as an efficient material for the potential applications in the domain of photocatalysis and also higher value of dielectric constant at room temperature makes them applicable in high energy storage devices.

WO3-Based Sensor Based on Hall Effect for NO2 Detection: Designed and Investigation

2010 ◽  
Vol 148-149 ◽  
pp. 1042-1046
Author(s):  
Jin Yang Lin ◽  
Yong Ai Zhang ◽  
Ling Jie Wang ◽  
Tai Liang Guo
Keyword(s):  
Magnetic Field ◽  
Response Time ◽  
Hall Effect ◽  
Tungsten Trioxide ◽  
Recovery Time ◽  
Room Temperature ◽  
Gas Sensing ◽  
Test Chamber ◽  
Tungsten Filament ◽  
Gas Sensing Properties

Novel tungsten oxide sensors were fabricated based on Hall Effect and their NO2 gas sensing properties were examined. Tungsten trioxide was grown by vapor evaporation of metal tungsten filament in an oxygen atmosphere. A WO3 thick film was deposited on the four Au electrode to be a WO3 sensor. The sensor was tested between magnetic field in a plastic test chamber. The gas sensing experiment revealed that at the NO2 concentration of 40 ppm, a sensitivity of 3.27, a response time of 36 s, and a recovery time of 45 s were observed at room-temperature. The effect of WO3 based on Hall Effect on the sensing characteristic is discussed.

scholarly journals UV irradiation effect on the electrical properties of Pb2MoO5 single crystal

2018 ◽  
Vol 26 (2) ◽  
pp. 63-66
Author(s):  
I. P. Volnyanskaya ◽  
M. P. Trubitsyn ◽  
D. M. Volnianskii ◽  
D. S. Bondar
Keyword(s):  
Electrical Properties ◽  
Single Crystal ◽  
Uv Irradiation ◽  
Room Temperature ◽  
Uv Light ◽  
Dipole Moments ◽  
Irradiation Effect ◽  
Deep Traps ◽  
Temperature Dependences ◽  
Ac Field

Electrical properties of Pb2MoO5 single crystal were studied in AC field (f=1 kHz) after irradiation with UV light (290 K). It was found that UV irradiation caused appearance of maximums on permittivity ε and conductivity σ temperature dependences, which were observed around 530 K. The anomalies of ε and σ vanished after annealing at 700 K and could be restored by subsequent UV irradiation performed at room temperature. The magnitude of ε and σ peaks increased for higher exposition time. Above 600 K conductivity σ was practically independent on irradiation. It is proposed that photoelectrons induced by UV light, are trapped by Mo located -within the oxygen tetrahedrons with vacancy VO in one of the vertexes. The dipole moments of (MoO3) groups reorient at VO hopping through the tetrahedron vertexes. Annealing at 700 K thermally decomposes (MoO3)- complexes. For T>600 K behavior of σ(T) is determined by conduction currents and nearly insensitive to UV irradiation. At high temperatures the photoelectrons do not contribute to conductivity since they are bound in (MoO3)- centers, recombine with holes or re-captured by more deep traps.

Ultrafast Response Humidity Sensor Based on Electrospun Porous BaTiO3 Nanofibers

2013 ◽  
Vol 319 ◽  
pp. 43-48 ◽  
Author(s):  
Hong Di Zhang ◽  
Chen Hao Sheng ◽  
Bin Sun ◽  
Yun Ze Long
Keyword(s):  
Electron Microscope ◽  
Recovery Time ◽  
Room Temperature ◽  
Humidity Sensor ◽  
Humidity Sensing ◽  
X Ray ◽  
Transmission Electron ◽  
Porous Microstructure ◽  
Humidity Sensing Properties ◽  
Scanning Electron

Nanocrystalline and porous barium titanate (BaTiO3) nanofibers with diameter 200-400 nm were synthesized via electrospinning and followed calcinations. The morphology and microstructure of the nanofibers were characterized using field emission scanning electron microscope, X-ray diffractometer and transmission electron microscope, respectively. And the electrical and humidity sensing properties of the nanofibers were also measured. The results reveal that the BaTiO3 nanofibers have a conductivity of about 0.3 S/cm, and show an ultrafast response time (~0.7 s) and a recovery time (~0.4 s) to humidity at room temperature. In addition, the sensing mechanism was also discussed briefly based on its nanocrystalline and porous microstructure of the electrospun material.

scholarly journals Photoreductive synthesis of monodispersed Au nanoparticles with citric acid as reductant and surface stabilizing reagent

RSC Advances ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 6187-6192 ◽  
Author(s):  
Yasuhiro Shiraishi ◽  
Haruki Tanaka ◽  
Hirokatsu Sakamoto ◽  
Satoshi Ichikawa ◽  
Takayuki Hirai
Keyword(s):  
Citric Acid ◽  
Uv Irradiation ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Uv Light

UV irradiation of water containing HAuCl4 and citric acid at room temperature successfully produces monodispersed Au nanoparticles. The size of Au particles is easily tuned by the intensity of UV light and the amount of citric acid.

scholarly journals β12 Phase Borophene Enhanced PANI Gas Sensor for CO and NH3 Detection

2021 ◽  
Author(s):  
Nevin Taşaltın ◽  
Cihat Taşaltın ◽  
Gülsen Baytemir ◽  
Selcan Karakuş
Keyword(s):  
Response Time ◽  
Recovery Time ◽  
Room Temperature ◽  
Critical Issue ◽  
Ammonia Concentration ◽  
Gas Detection ◽  
Medical Attention ◽  
Lung Failure ◽  
Sensitive Sensor ◽  
Co Gas

Abstract In cases where the carbon monoxide concentration reaches to 50 ppm, and ammonia concentration reaches to 25 ppm in indoor ambient, the symptoms such as lung failure, heart failure, brain damage are present, and urgent medical attention is required. Therefore, the development of a rapid and sensitive sensor in order to detect the level of CO and NH3 gases is the critical issue for health and the environment. In this study, borophene nanosheets with the β12 phased crystalline structure are produced by ultrasonic sonication. Using borophene nanosheets, Borophene and PANI: Borophene sensors are fabricated to investigate the CO and NH3 gas detection at room temperature. It has been observed that borophene enhances the CO and NH3 gas detection performance of PANI. The results reveal that borophene sensor detected 6 ppm CO gas with 30 s response time and 40 s recovery time, and 50 ppb NH3 gas with 40 s response time and 60 s recovery time at room temperature. On the other hand, PANI: Borophene sensor detected 6 ppm CO gas with 300 s response time and 320 s recovery time and 50 ppb NH3 gas with 100 s response time and 120 s recovery time at room temperature.

Room-Temperature ZnO Nanoparticle Ethanol Gas Sensors under UV Illumination

2012 ◽  
Vol 486 ◽  
pp. 39-43 ◽  
Author(s):  
S.P. Chang
Keyword(s):  
Gas Sensor ◽  
Gas Sensors ◽  
Spin Coating ◽  
Room Temperature ◽  
Uv Light ◽  
Light Illumination ◽  
Zno Nanoparticle ◽  
Uv Illumination ◽  
Potential Applications ◽  
Nanoparticle Film

A zinc oxide (ZnO) nanoparticle gas sensor was formed by spin coating. We annealed the film at 400, 600, and 800°C for 1 h in air to create a gas sensor. The responses of the gas sensor to ethanol under UV light illumination were investigated. We found that the ZnO nanoparticle film annealed at 800°C had the highest sensitivity. This can be attributed to the fact that the defects of ZnO nanoparticle film annealed at 800°C are considerably more than those for the film annealed at other temperatures. This study demonstrates that ZnO nanoparticles have potential applications as room-temperature ethanol sensors.

Growth and humidity-dependent electrical properties of bulk-like MoS2 thin films on Si

RSC Advances ◽  
2015 ◽  
Vol 5 (91) ◽  
pp. 74329-74335 ◽  
Author(s):  
Y. J. Liu ◽  
L. Z. Hao ◽  
W. Gao ◽  
Y. M. Liu ◽  
G. X. Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Magnetron Sputtering ◽  
Molybdenum Disulfide ◽  
Room Temperature ◽  
Dc Magnetron Sputtering ◽  
Humidity Sensing ◽  
Si Substrates ◽  
Sensing Characteristics

Bulk-like molybdenum disulfide (MoS2) thin films were deposited on Si substrates using a dc magnetron sputtering technique and n-MoS2/p-Si junctions show excellent humidity sensing characteristics at room temperature.

Magnetic and Magneto-Optical Properties of Sputtered Co-CeO2 Thin Films on Al2O3 (0001) Substrates with (100) Orientation

2011 ◽  
Vol 687 ◽  
pp. 117-121 ◽  
Author(s):  
Yuan Qiang Song ◽  
Huai Wu Zhang ◽  
Ying Li Liu ◽  
Yuan Xun Li ◽  
Qi Ye Wen
Keyword(s):  
Optical Properties ◽  
Magnetron Sputtering ◽  
Faraday Rotation ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Optical Measurements ◽  
Magnetic Oxide ◽  
Out Of Plane ◽  
Potential Applications ◽  
Optical Applications

Diluted magnetically doped CeO2 films is an attractive dilute magnetic oxide which would facilitate the practical realization of spintronic devices and may also be used to explore novel magneto-optical applications. In this experiments, 3 at% cobalt-doped CeO2 films with the stoichiometry of Ce0.97Co0.03O2-δ (CCO) were deposited by magnetron sputtering methods on Al2O3 (0001) substrates. The structural, magnetic, and magneto-optical properties were investigated. The results indicate that CCO films with CeO2 (100) orientation can readily be obtained via magnetron sputtering on Al2O3 (0001) substrates. Films are ferromagnetic at room temperature, which is anisotropic with an out-of-plane magnetization easy axis. Magneto-optical measurements exhibit a giant Faraday rotation of about 4800 deg/cm at 650 nm wavelength in out-of-plane direction. The excellent room-temperature ferromagnetism and the giant Faraday rotation in CCO films show highly potential applications in novel magneto-optical devices as well as in spintronics.

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