scholarly journals Effects of palladium on the optical and hydrogen sensing characteristics of Pd-doped ZnO nanoparticles

2014 ◽  
Vol 5 ◽  
pp. 1261-1267 ◽  
Author(s):  
Anh-Thu Thi Do ◽  
Hong Thai Giang ◽  
Thu Thi Do ◽  
Ngan Quang Pham ◽  
Giang Truong Ho
Keyword(s):  
Gas Sensors ◽  
Continuous Monitoring ◽  
Gas Sensing ◽  
Deep Level ◽  
Green Emission ◽  
High Sensitivity ◽  
Response Characteristics ◽  
Hydrogen Sensing ◽  
Sensitivity And Selectivity ◽  
Sensing Characteristics

The effect of palladium doping of zinc oxide nanoparticles on the photoluminescence (PL) properties and hydrogen sensing characteristics of gas sensors is investigated. The PL intensity shows that the carrier dynamics coincides with the buildup of the Pd-related green emission. The comparison between the deep level emission and the gas sensing response characteristics allows us to suggest that the dissociation of hydrogen takes place at PdZn-vacancies ([Pd 2+(4d9)]). The design of this sensor allows for a continuous monitoring in the range of 0–100% LEL H2 concentration with high sensitivity and selectivity.

Structural Approach to Improve the Response Characteristics of Copper Phthalocyanine Thin Film-Based NO2Gas Sensor

1997 ◽  
Vol 488 ◽  
Author(s):  
Tadashi Nagasawa ◽  
Kenji Murakami ◽  
Kenzo Watanabe
Keyword(s):  
Copper Phthalocyanine ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Film Deposition ◽  
Gas Sensitivity ◽  
Vacuum Sublimation ◽  
Response Characteristics ◽  
Atomic Force ◽  
Film Microstructure ◽  
Sensing Characteristics

AbstractIn order to realize a high-sensitivity, low temperature operable NO2gas sensor, thin films of at-form copper phthalocyanine (α-CuPc) have been deposited by vacuum sublimation. In this study, we have attempted to improve the gas-sensing characteristics through a modification of the film microstructure. Firstly, the gas sensitivity is remarkably increased by an insertion of higher-sensitive layer (vanadyl Pc film) between the α-CuPc film and the glass substrate in the low gas concentration range. Secondly, a reversibility in cycles of gas doping and dedoping is improved by film deposition on hydrofluoric acid-treated substrate. It is found from atomic force microscope analyses that this phenomenon may be closely related to a modification of the film microstructure.

Fabricating ZnO Nanorods Sensor for Chemical Gas Detection at Room Temperature

2007 ◽  
Vol 7 (12) ◽  
pp. 4439-4442 ◽  
Author(s):  
Chuanwei Cheng ◽  
Guoyue Xu ◽  
Haiqian Zhang ◽  
Yan Luo
Keyword(s):  
Gas Sensors ◽  
Potential Application ◽  
Room Temperature ◽  
Gas Sensing ◽  
Zno Nanorods ◽  
High Sensitivity ◽  
Gas Detection ◽  
Highly Sensitive ◽  
Sensing Characteristics

We present a sensor fabricated by simply casting ZnO nanorods on a microelectrodes array for chemical gas detection at room temperature. The ammonia and ethanol gas sensing characteristics were carefully investigated. The sensor exhibited high sensitivity for both ammonia and ethanol gases. The response and recover time are less than 20 seconds, respectively. Present results demonstrate the potential application of ZnO nanorods for fabricating highly sensitive gas sensors.

Schottky diodes based on 2D materials for environmental gas monitoring: a review on emerging trends, recent developments and future perspectives

2021 ◽  
Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout
Keyword(s):  
Gas Sensing ◽  
2D Materials ◽  
Schottky Diodes ◽  
High Sensitivity ◽  
Future Perspectives ◽  
Working Temperature ◽  
Emerging Trends ◽  
Gas Sensing Properties ◽  
Recent Developments ◽  
Sensitivity And Selectivity

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.

scholarly journals Transforming Pt-SnO2 Nanoparticles into Pt-SnO2 Composite Nanoceramics for Room-Temperature Hydrogen-Sensing Applications

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2123
Author(s):  
Ming Liu ◽  
Caochuang Wang ◽  
Pengcheng Li ◽  
Liang Cheng ◽  
Yongming Hu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Sintering Temperature ◽  
Sno2 Nanoparticles ◽  
Hydrogen Sensing ◽  
Sensing Applications ◽  
Nanostructured Metal Oxides ◽  
Low Dimensional ◽  
Sensing Characteristics ◽  
Nanostructured Metal

Many low-dimensional nanostructured metal oxides (MOXs) with impressive room-temperature gas-sensing characteristics have been synthesized, yet transforming them into relatively robust bulk materials has been quite neglected. Pt-decorated SnO2 nanoparticles with 0.25–2.5 wt% Pt were prepared, and highly attractive room-temperature hydrogen-sensing characteristics were observed for them all through pressing them into pellets. Some pressed pellets were further sintered over a wide temperature range of 600–1200 °C. Though the room-temperature hydrogen-sensing characteristics were greatly degraded in many samples after sintering, those samples with 0.25 wt% Pt and sintered at 800 °C exhibited impressive room-temperature hydrogen-sensing characteristics comparable to those of their counterparts of as-pressed pellets. The variation of room-temperature hydrogen-sensing characteristics among the samples was explained by the facts that the connectivity between SnO2 grains increases with increasing sintering temperature, and Pt promotes oxidation of SnO2 at high temperatures. These results clearly demonstrate that some low-dimensional MOX nanocrystals can be successfully transformed into bulk MOXs with improved robustness and comparable room-temperature gas-sensing characteristics.

High sensitivity and selectivity chlorine gas sensors based on 3D open porous SnO2 synthesized by solid-state method

2019 ◽  
Vol 45 (16) ◽  
pp. 20566-20574 ◽  
Author(s):  
Weiming Zhang ◽  
Qiang Li ◽  
Chao Wang ◽  
Jiangwei Ma ◽  
Chao Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Gas Sensors ◽  
High Sensitivity ◽  
Solid State Method ◽  
Chlorine Gas ◽  
Sensitivity And Selectivity ◽  
State Method

scholarly journals Discriminable Sensing Response Behavior to Homogeneous Gases Based on n-ZnO/p-NiO Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 785 ◽  
Author(s):  
Wen-Dong Zhou ◽  
Davoud Dastan ◽  
Jing Li ◽  
Xi-Tao Yin ◽  
Qi Wang
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Sol Gel ◽  
High Sensitivity ◽  
Oxide Semiconductor ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
P Type ◽  
Type Response ◽  
Properties Of Composites

Metal oxide semiconductor (MOS) gas sensors have the advantages of high sensitivity, short response-recovery time and long-term stability. However, the shortcoming of poor discriminability of homogeneous gases limits their applications in gas sensors. It is well-known that the MOS materials have similar gas sensing responses to homogeneous gases such as CO and H2, so it is difficult for these gas sensors to distinguish the two gases. In this paper, simple sol–gel method was employed to obtain the ZnO–xNiO composites. Gas sensing performance results illustrated that the gas sensing properties of composites with x > 0.425 showed a p-type response to both CO and H2, while the gas sensing properties of composites with x < 0.425 showed an n-type response to both CO and H2. However, it was interesting that ZnO–0.425NiO showed a p-type response to CO but an discriminable response (n-type) to H2, which indicated that modulating the p-type or n-type semiconductor concentration in p-n composites could be an effective method with which to improve the discriminability of this type of gas sensor regarding CO and H2. The phenomenon of the special gas sensing behavior of ZnO–0.425NiO was explained based on the experimental observations and a range of characterization techniques, including XRD, HRTEM and XPS, in detail.

scholarly journals Preparation of Flower-Like Cu-WO3Nanostructures and Their Acetone Gas Sensing Performance

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hao Zhou ◽  
Dong-Yao Xu ◽  
Hai-Qing Zuo ◽  
Wei Liu ◽  
Shuang Lin
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
High Sensitivity ◽  
Test System ◽  
Static State ◽  
Acetone Concentration ◽  
Detection Range ◽  
Gas Sensing Properties ◽  
Linear Fit

Urchin-like Cu-W18O49and flower-like Cu-WO3structures were successfully synthesized using a hydrothermal process followed by calcination. The synthesized products were characterized using XRD, SEM, and TEM. The results revealed that the as-prepared urchin-like and flower-like samples with monoclinic structures, which were approximately 1 μm and 1-2 μm, respectively, possessed microflower architecture assembled by the nanosheet. In addition, the gas sensing properties of monoclinic-structured Cu-WO3to acetone were measured using a static state gas sensing test system. The sensor based on the flower-like Cu-WO3nanostructures, which were calcined at 600°C, exhibited high sensitivity toward 10 ppm acetone at an optimum temperature of 110°C, and the maximum sensitivity reached 40, which was approximately four times higher than that of urchin-like WO3that was annealed at 300°C. The sensitivity was improved by increasing the acetone concentration. The detection limit was as low as 1 ppm. Using linear fit, the sensor was determined to be sufficiently sensitive to detect acetone in a detection range of 1 to 10 ppm even in the presence of interfering gases, which suggests that this type of sensor has excellent selectivity and has the potential for use in acetone gas sensors in the future.

Semiconductor dimethylamine gas sensors with high sensitivity and selectivity

1995 ◽  
Vol 25 (1-3) ◽  
pp. 375-379 ◽  
Author(s):  
Yuji Takao ◽  
Masahiko Nakanishi ◽  
Tomohiro Kawaguchi ◽  
Yasuhiro Shimizu ◽  
Makoto Egashira
Keyword(s):  
Gas Sensors ◽  
High Sensitivity ◽  
Sensitivity And Selectivity
Sign in / Sign up

Export Citation Format

Share Document