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

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.

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sweejiang Yoo ◽  
Xin Li ◽  
Yuan Wu ◽  
Weihua Liu ◽  
Xiaoli Wang ◽  
...  

Reduced graphene oxide (rGO) based chemiresistor gas sensor has received much attention in gas sensing for high sensitivity, room temperature operation, and reversible. Here, for the first time, we present a promising chemiresistor for ammonia gas detection based on tannic acid (TA) functionalized and reduced graphene oxide (rGOTA functionalized). Green reductant of TA plays a major role in both reducing process and enhancing the gas sensing properties ofrGOTA functionalized. Our results showrGOTA functionalizedonly selective to ammonia with excellent respond, recovery, respond time, and recovery times.rGOTA functionalizedelectrical resistance decreases upon exposure to NH3where we postulated that it is due to n-doping by TA and charge transfer betweenrGOTA functionalizedand NH3through hydrogen bonding. Furthermore,rGOTA functionalizedhinders the needs for stimulus for both recovery and respond. The combination of greener sensing material and simplicity in overall sensor design provides a new sight for green reductant approach of rGO based chemiresistor gas sensor.


2019 ◽  
Vol 288 ◽  
pp. 625-633 ◽  
Author(s):  
Hwan-Seok Jeong ◽  
Min-Jae Park ◽  
Soo-Hun Kwon ◽  
Hyo-Jun Joo ◽  
Hyuck-In Kwon

2015 ◽  
Vol 654 ◽  
pp. 94-98 ◽  
Author(s):  
Roman Yatskiv ◽  
María Verde ◽  
Jan Grym

Arrays of vertically well aligned ZnO nanorods (NRs) were prepared on nanostructured ZnO films using a low temperature hydrothermal method. We propose the use of the low cost, environmentally friendly electrophoretic deposition technique (EPD) as seeding procedure, which allows the obtaining of homogeneous, well oriented nanostructured ZnO thin films. ZnO nanorod arrays were covered with graphite in order to prepare graphite/ZnO NRs junctions. These nanostructured junctions showed promising current-voltage rectifying characteristics and gas sensing properties at room temperature.


Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6475
Author(s):  
Jiahui Guo ◽  
Weiwei Li ◽  
Xuanliang Zhao ◽  
Haowen Hu ◽  
Min Wang ◽  
...  

Semiconducting metal oxides can detect low concentrations of NO2 and other toxic gases, which have been widely investigated in the field of gas sensors. However, most studies on the gas sensing properties of these materials are carried out at high temperatures. In this work, Hollow SnO2 nanofibers were successfully synthesized by electrospinning and calcination, followed by surface modification using ZnO to improve the sensitivity of the SnO2 nanofibers sensor to NO2 gas. The gas sensing behavior of SnO2/ZnO sensors was then investigated at room temperature (~20 °C). The results showed that SnO2/ZnO nanocomposites exhibited high sensitivity and selectivity to 0.5 ppm of NO2 gas with a response value of 336%, which was much higher than that of pure SnO2 (13%). In addition to the increase in the specific surface area of SnO2/ZnO-3 compared with pure SnO2, it also had a positive impact on the detection sensitivity. This increase was attributed to the heterojunction effect and the selective NO2 physisorption sensing mechanism of SnO2/ZnO nanocomposites. In addition, patterned electrodes of silver paste were printed on different flexible substrates, such as paper, polyethylene terephthalate and polydimethylsiloxane using a facile screen-printing process. Silver electrodes were integrated with SnO2/ZnO into a flexible wearable sensor array, which could detect 0.1 ppm NO2 gas after 10,000 bending cycles. The findings of this study therefore open a general approach for the fabrication of flexible devices for gas detection applications.


2020 ◽  
Vol 65 ◽  
pp. 145-155
Author(s):  
Hadi Riyahi Madvar ◽  
Zoheir Kordrostami ◽  
Samaneh Hamedi

A resistive ethanol gas sensor with a high sensitivity has been proposed. The fabricated gas sensor has a very promising response and recovery at room temperature. The proposed sensor has been fabricated by depositing sensitive nanostructured material on printed circuit board interdigitated electrodes. As the sensitive material, ZnO nanorods of high uniformity have been synthesized by hydrothermal method and then decorated by PbS nanoparticles. The synthesized decorated nanorods were characterized by X-ray diffraction and scanning electron microscope which confirmed the formation of the desired nanostructures. The ethanol gas sensing properties of the ZnO nanorods decorated with PdS nanoparticles was measured in a test chamber. The minimum ethanol concentration detected by the sensor has been 10 ppm. The results showed the higher sensitivity of the proposed sensor to the ethanol at room temperature compared to similar works.


Author(s):  
Zhuo Liu ◽  
He Lv ◽  
Ying Xie ◽  
Jue Wang ◽  
Jiahui Fan ◽  
...  

The very diverse two-dimensional (2D) materials have bloomed in NO2 gas sensing application that provide new opportunities and challenges in function oriented gas sensors. In this work, a 2D/2D/2D structure...


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Vo Thanh Duoc ◽  
Dang Thi Thanh Le ◽  
Nguyen Duc Hoa ◽  
Nguyen Van Duy ◽  
Chu Manh Hung ◽  
...  

Room-temperature gas sensors are attracting attention because of their low power consumption, safe operation, and long-term stability. Herein, ZnO nanorods (NRs) and nanowires (NWs) were on-chip grown via a facile hydrothermal method and used for room-temperature NO2 gas sensor applications. The ZnO NRs were obtained by a one-step hydrothermal process, whereas the NWs were obtained by a two-step hydrothermal process. To obtain ZnO NW sensor, the length of NRs was controlled short enough so that none of the nanorod-nanorod junction was made. Thereafter, the NWs were grown from the tips of no-contact NRs to form nanowire-nanowire junctions. The gas-sensing characteristics of ZnO NRs and NWs were tested against NO2 gas at room temperature for comparison. The gas-sensing characteristics of the sensors were also tested at different applied voltages to evaluate the effect of the self-activated gas-sensing performance. Results show that the diameter of ZnO NRs and NWs is the dominant parameter of their NO2 gas-sensing performance at room temperature. In addition, self-activation by local heating occurred for both sensors, but because the NWs were smaller and sparser than the NRs, local heating thus required a lower applied voltage with maximal response compared with the NRs.


2004 ◽  
Vol 828 ◽  
Author(s):  
Song-Kap Duk ◽  
Duk-Dong Lee

ABSTRACTIn the study, low power micro gas sensors operated at room temperature for the detection of NH3 and NOx gases are proposed. As candidate material of gas sensor for NH3 gas detection at room temperature, polyaniline(PANi) synthesized by chemical polymerization was selected. And Te(Tellurium) thin film was used for NOx gas detection at room temperature. By using these sensing materials, micro gas sensors for room temperature operation were prepared and measured the response characteristics for NH3 and NOx.In case of PANi sensor, the structure was inverted staggered FET type having advantage of useful one for Lab-On-a-Chip. The operating principle of the sensor is based on the change in work function of PANi film caused by adsorption of gas molecules in air on the film surface. The change in work function was measured indirectly from that in gate voltage of the FET device. The responses to various gases (NH3, CH4, Methanol and CH3CN) were obtained in gate voltage step mode in R.H. 30%. And in case of Te sensor, the sensing material was thermally evaporated on glass substrate. The thickness and annealing temperature were 500 Å −2000 Å and 100 °C −300 °C, respectively. The Te-based micro gas sensor exhibited high sensitivity to NOx and good selectivity against CO and hydro-carbon gases. And by adding Ti to Te film, the sensor has a good selectivity to CO gas.


2014 ◽  
Vol 5 ◽  
pp. 1261-1267 ◽  
Author(s):  
Anh-Thu Thi Do ◽  
Hong Thai Giang ◽  
Thu Thi Do ◽  
Ngan Quang Pham ◽  
Giang Truong Ho

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.


Sign in / Sign up

Export Citation Format

Share Document