scholarly journals Humidity Sensing and Photodetection Based on Tin Disulfide Nanosheets

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1028
Author(s):  
Der-Yuh Lin ◽  
Hung-Pin Hsu ◽  
Han-Sheng Hu ◽  
Yu-Cheng Yang ◽  
Chia-Feng Lin ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Electrode Spacing ◽  
X Ray Diffraction ◽  
Humidity Sensing ◽  
X Ray ◽  
Tin Disulfide ◽  
Human Respiration ◽  
Response And Recovery ◽  
H2o2 Oxidation ◽  
Measured Response

Tin disulfide has substantial importance for two-dimensional material-based optoelectronics and sensors due to its unique optoelectrical properties. In this report, we fabricate SnS2 nanosheets using the low-pressure thermal sulfurization process, whose crystal structure and surface morphology are confirmed by X-ray diffraction (XRD) and scanning electron microscope (SEM) measurements. From photoconductivity measurement and photocurrent mapping, we observe smaller electrode spacing of SnS2 thin films can enhance photodetection. Then, by the H2O2 oxidation processing, we transform SnS2 to SnO2 to detect humidity. The measured response and recovery time can be optimized to 5.6 and 1.0 s, respectively, shorter than those of commercial DHT11 humidity sensor of 32 and 34 s. At suitable bias, humidity sensor can detect human respiration properly at room temperature. Our results show that SnS2 nanosheets exhibit reasonable performance for emergent photodetector applications and humidity sensing.

scholarly journals Effects of Surfactants on the Performance ofCeO2Humidity Sensor

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Chunjie Wang ◽  
Aihua Zhang ◽  
Hamid Reza Karimi
Keyword(s):  
Recovery Time ◽  
Cetyltrimethylammonium Bromide ◽  
Humidity Sensor ◽  
X Ray Diffraction ◽  
Humidity Sensors ◽  
X Ray ◽  
Transmission Electron ◽  
Three Samples ◽  
Different Types ◽  
Response And Recovery

NanosizedCeO2powders were synthesized via hydrothermal method with different types of surfactants (polyethylene glycol (PEG), cetyltrimethylammonium bromide (CTAB), and sodium dodecylbenzenesulfonate (SDBS)). X-ray diffraction, Raman spectroscopy, and transmission electron microscopy were utilized to characterize the phase structures and morphologies of the products. The sample with CTAB as surfactant (CeO2-C) has the largest specific surface area and the smallest particle size among these three samples. The humidity sensor fabricated byCeO2-C shows higher performance than those usedCeO2-P andCeO2-S. The impedance of theCeO2-C sensor decreases by about five orders of magnitude with relative humidity (RH) changing from 15.7 to 95%. The response and recovery time are 7 and 7 s, respectively. These results indicate that the performance ofCeO2humidity sensors can be improved effectively by the addition of cationic surfactant.

scholarly journals Tin Disulfide-Coated Microfiber for Humidity Sensing with Fast Response and High Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Small Diameter ◽  
High Sensitivity ◽  
Large Change ◽  
Small Variation ◽  
Response Speed ◽  
Fast Response ◽  
Tin Disulfide ◽  
Recovery Times ◽  
Response And Recovery

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.

scholarly journals Highly Porous NiO Nanoflower-based Humidity Sensor Grown on Seedless Glass Substrate via One-Step Simplistic Immersion Method

2019 ◽  
Vol 9 (1) ◽  
pp. 5718-5722
Keyword(s):  
Humidity Sensor ◽  
Average Crystallite Size ◽  
Bandgap Energy ◽  
Voltage Measurement ◽  
X Ray Diffraction ◽  
Immersion Method ◽  
Glass Substrates ◽  
Response And Recovery ◽  
One Step ◽  
Highly Porous

A highly porous nickel oxide (NiO) nanoflower was deposited directly onto glass substrates by the simplistic immersion method. The nanostructural property of the NiO was studied by X-ray diffraction pattern and obtained high crystal quality after annealing at 500 °Ϲ with an average crystallite size of 15.5 nm. The optical characterization was measured by ultraviolet-visible spectroscopy, with an average transmittance of 58 %. The value of 3.63 eV was estimated and confirmed as NiO bandgap energy. The current-voltage measurement result indicates that the NiO nanoflower has good electrical properties with resistance, resistivity, and conductivity value of 2.31 MΩ, 2.12 Ω.cm, and 4.71 × 10-1 S.cm-1 , respectively. The NiO is capable of performing satisfactorily as humidity sensor with a sensitivity of 138 with the response and recovery time were estimated at 389 s and 172 s, respectively. Besides, this sensor has stability at a humidity level of 40 - 90% relative humidity.

Fabrication of TiO2 sensor using rapid breakdown anodization method to measure pressure, humidity and sense gases at room temperature

2019 ◽  
pp. 1694-1703
Author(s):  
Reem Saadi Khaleel ◽  
Mustafa Shakir Hashim
Keyword(s):  
Room Temperature ◽  
Average Pressure ◽  
Spherical Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Recovery Times ◽  
Sensitivity And Selectivity ◽  
Response And Recovery ◽  
Anodization Method ◽  
Rapid Breakdown Anodization

Rapid breakdown anodization (RBA) process was used to fabricate TiO2 sensor to measure pressure and humidity and sense gases at room temperature. This chemical process transformed Ti to its oxide (TiO2) as a powder with amorphous phase as X ray diffraction (XRD) technique confirmed.  This oxide consisted from semi spherical nanoparticles and titania nanotubes (TNTs) as Scanning electron microscope (SEM) technique showed.  TiO2 powder was deposited on Ti substrates by using electrophoretic deposition (EPD) method.   Average pressure sensitivity was 0.34 MΩ/bar and hysteresis area was 1.4 MΩ .bar. Resistance of TiO2 decreased exponentially with the increasing of relative humidity (RH%). The sensitivity% of TiO2 for RH% was greater than 70% in the range of (50-95). TiO2 was tested as a sensor for Ammonia, Ethanol and Methanol. Its sensitivity and selectivity towards Ammonia were the greatest but the shortest response and recovery times were recorded toward Methanol.

Detection of accumulated continuously ethanol concentration by ZnO–SnO2 composite nanorods sensor

2021 ◽  
pp. 2150395
Author(s):  
Xiang-Bing Li ◽  
Da-Qian Mo ◽  
Xiao-Yan Niu ◽  
Qian-Qian Zhang ◽  
Shu-Yi Ma ◽  
...  
Keyword(s):  
Recovery Time ◽  
Ethanol Concentration ◽  
Physical Adsorption ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Atomic Force ◽  
Electrospinning Method ◽  
Response And Recovery ◽  
Composite Nanorods

ZnO–SnO2 composite nanorods with rough surfaces were synthesized via a coaxially nested needle electrospinning method. The morphology and nanostructure were characterized by scanning electron microscopy, atomic force microscope, EDS mapping, nitrogen physical adsorption, and X-ray diffraction. The synthesis mechanisms of ZnO–SnO2 nanorods were discussed, which combined the gas sensitivity advantages of different materials. ZnO–SnO2 nanorods sensor with good ethanol gas sensitivity achieved accurate measurement of continuous ethanol concentration. The sensor exhibited good selectivity to ethanol in the presence of formaldehyde, methanol, acetone, acetic acid, benzene, and xylene at 290[Formula: see text]C. The response and recovery time to 100 ppm ethanol were about 13 and 35 s, respectively. The energy band, barrier, charge transfer of ZnO–SnO2 composite material was discussed, and its optimization of gas sensitivity was analyzed in detail.

scholarly journals Synthesis of ZnO-CuO flower-like hetero-nanostructures as volatile organic compounds (VOCs) sensor at room temperature

2018 ◽  
Vol 36 (3) ◽  
pp. 452-459
Author(s):  
Raad S. Sabry ◽  
Roonak Abdul Salam A. Alkareem
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Room Temperature ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Volatile Organic ◽  
Recovery Times ◽  
Coating Methods ◽  
Response And Recovery

AbstractZnO-CuO flower-like hetero-nanostructures were successfully prepared by combining hydrothermal and dip coating methods. Flower-like hetero-nanostructures of ZnO-CuO were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and UV-Vis. The sensing properties of ZnO-CuO flower-like hetero-nanostructures to volatile organic compounds (VOCs) were evaluated in a chamber containing acetone or isopropanol gas at room temperature. The sensitivity of ZnO-CuO flower-like hetero-nanostructures to VOCs was enhanced compared to that of pure leafage-like ZnO nanostructures. Response and recovery times were about 5 s and 6 s to 50 ppm acetone, and 10 s and 8 s to 50 ppm isopropanol, respectively. The sensing performance of ZnO-CuO flower-like hetero-nanostructures was attributed to the addition of CuO that led to formation of p-n junctions at the interface between the CuO and ZnO. In addition, the sensing mechanism was briefly discussed.

scholarly journals Nanocrystalline Hexagonal Shaped CdS Thin Films for Photoconducting Application

2014 ◽  
Vol 36 ◽  
pp. 153-167
Author(s):  
S.M. Patil ◽  
P.H. Pawar
Keyword(s):  
Thin Films ◽  
Cadmium Sulphide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analytical Technique ◽  
Deposition Parameters ◽  
Cds Thin Films ◽  
Response And Recovery ◽  
Nanocrystalline Thin Films

Nanocrystalline thin films of cadmium sulphide were prepared by chemical bath deposition technique onto glass substrate at 60 °C. The deposition parameters were optimized to obtain good quality of nanocrystalline thin films such as, time, precursor concentration, temperature of deposition and pH of the solution. The studies on crystal structure, composition, surface morphology, electrical conductivity and photoconductivity of the films were carried out by using different analytical technique. Characterization includes X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray analysis (EDAX), Electrical and photoconductivity. The response and recovery time of the thin film were measured and presented.

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.

Humidity sensing properties of spray deposited Fe doped TiO2 thin film

2021 ◽  
Vol 42 (12) ◽  
pp. 122805
Author(s):  
Dipak L Gapale ◽  
Pranav P. Bardapurkar ◽  
Sandeep A. Arote ◽  
Sanjaykumar Dalvi ◽  
Prashant Baviskar ◽  
...  
Keyword(s):  
Spray Pyrolysis Technique ◽  
Structural Parameters ◽  
Texture Coefficient ◽  
Volume Percentage ◽  
Humidity Sensing ◽  
X Ray ◽  
Sensing Properties ◽  
Dislocation Densities ◽  
Response And Recovery ◽  
Humidity Sensing Properties

Abstract In the present work, ferrite (Fe) doped TiO2 thin films with different volume percentage (vol%) were synthesized using a spray pyrolysis technique. The effect of Fe doping on structural properties such as crystallite size, texture coefficient, microstrain, dislocation densities etc. were evaluated from the X ray diffratometry (XRD) data. XRD data revealed a polycrystalline anatase TiO2 phase for sample synthesized up to 2 vol% and mixed anatase and rutile crystalline phase for sample synthesized at 4 vol% Fe doped TiO2. The crystalline size was observed to decrease with increase in Fe dopant vol% and also other structural parameters changes with Fe dopant percentage. In the present work, electrical resistance was observed to decrease with a rise in Fe dopant vol% and temperature of the sample. Thermal properties like temperature coefficient of resistance and activation energy also showed strong correlation with Fe dopant vol%. Humidity sensing properties of the synthesized sample altered with a change in Fe dopant vol%. In the present paper, maximum sensitivity of about 88.7% for the sample synthesized with 2 vol% Fe doped TiO2 and also the lowest response and recovery time of about 52 and 3 s were reported for the same sample.

Acetylene Sensing by ZnO/TiO2 Nanoparticles

2020 ◽  
Vol 15 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Zhi-Cheng Zhong ◽  
Zhao-Jun Jing ◽  
Kui-Yuan Liu ◽  
Tong Liu
Keyword(s):  
Gas Sensors ◽  
Operating Temperature ◽  
Sol Gel ◽  
Fast Response ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Recovery Times ◽  
Response And Recovery ◽  
Hydrothermal Methods

We adopted the sol–gel and hydrothermal methods to prepare the TiO2 nanomaterials doped with ZnO. We adopted X-ray diffraction, scanning electron microscopy, and the Brunauer–Emmett–Teller method to investigate the materials’ structures and morphologies. The results showed that the prepared TiO2 nanomaterials had uniform size and good dispersibility. Gas sensors were fabricated and their performances in acetylene sensing were assessed. The results show that the sensor prepared with the ZnO/TiO2 nanomaterial doped with 10 wt% ZnO gave fast response and recovery times for acetylene gas at different concentrations. When the operating temperature was 280 °C, the gas sensor detected 200 ppm acetylene gas with a response sensitivity of 9.9, a response time of 5 s, and a recovery time of 2 s.

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