Preparation and Characterization of BCN Nanotubes and their Sensitivity to NOx at Room Temperature

2012 ◽  
Vol 616-618 ◽  
pp. 1778-1782
Author(s):  
Ying Yang ◽  
Zhuan Fang Zhang ◽  
Kan Kan ◽  
Yun Long Ge ◽  
Yan Li Sun ◽  
...  

Novel BCN nanotubes (BCN NTs) for NOx gas sensor have been synthesized by the CVD method at room temperature. The BCN NTs have been investigated with XPS and TEM. The diameter of the BCN NTs is in the range of 20-50 nm and the tubes exhibit bamboolike structure. By using NOx as a probe molecule, the BCN NTs exhibit excellent sensing performance in terms of high response, fast response and good stability at room temperature. The outstanding performance in gas sensing of BCN NTs owes to their one-dimensional nanostructures, more defects and active sites doping carbon nanotubes with B, N. The possible gas sensing mechanism of the BCN NTs is explained by a model in which the effect of NOx adsorption on BCN nanotubes and the electronic transport properties increase after doping carbon nanotubes with B, N.

2021 ◽  
Vol 6 (1) ◽  
pp. 25
Author(s):  
Sanghamitra Ghosal ◽  
Partha Bhattacharyya

The systematic optimization of surface engineering (dimensionality) indeed plays a crucial role in achieving efficient vapor-sensing performance. Among various semiconducting metal oxides, owing to some of its unique features and advantages, ZnO has attracted researchers on a global scale due to its application in various fields, including chemical sensors. The concomitant optimization of the surface attributes (varying different dimensions) of ZnO have become a sensation for the entire research community. Moreover, the small thickness and extremely large surface of exfoliated 2D nanosheets render the gas sensing material an ideal candidate for achieving strong coupling with different gas molecules. However, temperature is a crucial factor in the field of chemical sensing. Recently, graphene-based gas sensors have attracted attention due to their variety of structures, unique sensing performances and room temperature working conditions. In this work, a highly sensitive and fast responsive low temperature (60 °C)-based ethanol sensor, based on RGO/2D ZnO nanosheets hybrid structure, is reported. After detailed characterizations, the vapor sensing potentiality of this sensor was tested for the detection of ethanol. The ethanol sensor offered the response magnitude of 89% (100 ppm concentration) with response and recovery time of 12 s/29 s, respectively. Due to excessively high number of active sites for VOC interaction, with high yield synthesis process and appreciably high carrier mobility, this has paved the way for developing future generation, miniaturized and flexible (wearable) vapor sensor devices, meeting the multidimensional requirements for traditional and upcoming (health/medical sector) applications. The underlying mechanistic framework for vapor sensing, using this hybrid junction, is explained with the Energy Band Diagram.


2007 ◽  
Vol 601 (13) ◽  
pp. 2832-2835 ◽  
Author(s):  
M. Commisso ◽  
A. Bonanno ◽  
M. Minniti ◽  
P. Barone ◽  
P. Riccardi ◽  
...  

2015 ◽  
Vol 10 (1) ◽  
pp. 13-20
Author(s):  
Elisabete Galeazzo ◽  
Marcos C. Moraes ◽  
Henrique E. M. Peres ◽  
Michel O. S. Dantas ◽  
Victor G. C. Lobo ◽  
...  

Intensive research has been focused on investigating new sensing materials, such as carbon nanotubes (CNT) because of their promising characteristics. However, there are challenges related to their application in commercial devices such as sensitivity, compatibility, and complexity of miniaturization, among others. We report the study of the electrical behavior of devices composed by multi-walled carbon nanotubes (MWCNT) deposited between aluminum electrodes on glass substrates by means of dielectrophoresis (DEP), which is a simple and cost-effective method. The devices were fabricated by varying the DEP process time. Remarkable changes in their electric resistance were noticed depending on the MWCNT quantities deposited. Other electrical properties of devices such as high sensitivity, fast response time and stability are also characterized in humid environment. A humidity sensing mechanism is proposed on the basis of charge transfer between adsorbed water molecules and the MWNTC surface or between water and the glass surface.


Author(s):  
Huynh Anh Hoang ◽  
Huynh Quyen

Since the end of the 20th century, nanomaterials such as carbon nanotubes (CNTs) have been considered as one of the greatest achievements in the field of material science. Nowadays, further research on CNTs is still being conducted to unfold the full potential of this material. Generally, CNTs production methods have been extensively studied, specifically on CNTs synthesis route via liquefied hydrocarbon gas in the presence of a catalyst. From the synthesized material, further investigation including characterization and investigation of this nano size system’s effects on the physics, chemical, mechanical rules applied to macroscopic (bulk materials) and microscopic systems (atoms, molecules). In this present work, we demonstrated the research results of the synthesis of nano-carbon materials from a liquefied hydrocarbon gas (Liquefied Petroleum Gas: LPG) and its application to red phenol absorption in the liquid phase. CNTs used in this study were synthesized by chemical vapor deposition (CVD) method with Fe /ℽ-Al2O3 as the catalyst. The research results demonstrated that CNTs synthesized from LPG in this work were reported to be multi-walled tubes (MWCNTs: Multi-Walled Carbon Nanotubes) with physical characteristics including average internal and external diameters were of 6 nm and 17 nm, respectively. The measured specific surface suggested by BET data was 200 m2/g. The experimental study of red phenol adsorption by MWCNTs showed that the adsorption process followed both Freundlich and Langmuir isotherm adsorption models with the maximum monolayer adsorption capacity of 47.2 mg/g. The research results again showed that it was possible to synthesize MWCNTs from hydrocarbon gas sources via the CVD method by utilizing catalysts. Additionally, red phenol absorption via such material had shown to follow both Freundlich and Langmuir isotherm model, which allow further characterization of this material using Raman, EDX, SEM, TEM, BET, in order to extend the library database on the characterization of the reported synthesized material.


Author(s):  
Monika Kwoka ◽  
Michal A. Borysiewicz ◽  
Pawel Tomkiewicz ◽  
Anna Piotrowska ◽  
Jacek Szuber

In this paper a novel type of a highly sensitive gas sensor device based on the surface photovoltage effect is described. The developed surface photovoltage gas sensor is based on a reverse Kelvin probe approach. As the active gas sensing electrode the porous ZnO nanostructured thin films are used deposited by the direct current (DC) reactive magnetron sputtering method exhibiting the nanocoral surface morphology combined with an evident surface nonstoichiometry related to the unintentional surface carbon and water vapor contaminations. Among others, the demonstrated SPV gas sensor device exhibits a high sensitivity of 1 ppm to NO2 with a signal to noise ratio of about 50 and a fast response time of several seconds under the room temperature conditions.


2009 ◽  
Vol 2009 ◽  
pp. 1-24 ◽  
Author(s):  
Yun Wang ◽  
John T. W. Yeow

Gas sensors have attracted intensive research interest due to the demand of sensitive, fast response, and stable sensors for industry, environmental monitoring, biomedicine, and so forth. The development of nanotechnology has created huge potential to build highly sensitive, low cost, portable sensors with low power consumption. The extremely high surface-to-volume ratio and hollow structure of nanomaterials is ideal for the adsorption of gas molecules. Particularly, the advent of carbon nanotubes (CNTs) has fuelled the inventions of gas sensors that exploit CNTs' unique geometry, morphology, and material properties. Upon exposure to certain gases, the changes in CNTs' properties can be detected by various methods. Therefore, CNTs-based gas sensors and their mechanisms have been widely studied recently. In this paper, a broad but yet in-depth survey of current CNTs-based gas sensing technology is presented. Both experimental works and theoretical simulations are reviewed. The design, fabrication, and the sensing mechanisms of the CNTs-based gas sensors are discussed. The challenges and perspectives of the research are also addressed in this review.


Nanoscale ◽  
2020 ◽  
Vol 12 (33) ◽  
pp. 17185-17190 ◽  
Author(s):  
Naoyuki Kanda ◽  
Yusuke Nakanishi ◽  
Dan Liu ◽  
Zheng Liu ◽  
Tsukasa Inoue ◽  
...  

Confinement of van der Waals materials inside 1D carbon nanotubes leads to properties not observed in the bulk.


2010 ◽  
Vol 663-665 ◽  
pp. 393-396
Author(s):  
Fu Ru Zhong ◽  
Xiao Yi Lv ◽  
Zhen Hong Jia

We have investigated the morphology and photoluminescence (PL) of Zinc Oxide (ZnO) and Zinc sulphide (ZnS) compound grown on porous silicon at room temperature. Under different excitation wavelengths (320 nm, 340nm, 370 nm), the photoluminescence (PL) spectra of PS-ZnS-ZnO composites were different, and at 550nm there is a strong photoluminescence peak. Energy dispersive spectroscopy (EDS) has been carried out to evaluate the existing of ZnO/ZnS compound. In addition, the scanning electron microscopy (SEM) observation shows that the morphology of the PS-ZnS-ZnO composites was well grown on porous silicon.


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