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Article
Publication date: 15 September 2021

Srinivas Rao Sriram, Saidireddy Parne, Venkata Satya Chidambara Swamy Vaddadi, Damodar Edla, Nagaraju P., Raji Reddy Avala, Vijayakumar Yelsani and Uday Bhasker Sontu

This paper aims to focus on the basic principle of WO3 gas sensors to achieve high gas-sensing performance with good stability and repeatability. Metal oxide-based gas

Abstract

Purpose

This paper aims to focus on the basic principle of WO3 gas sensors to achieve high gas-sensing performance with good stability and repeatability. Metal oxide-based gas sensors are widely used for monitoring toxic gas leakages in the environment, industries and households. For better livelihood and a healthy environment, it is extremely helpful to have sensors with higher accuracy and improved sensing features.

Design/methodology/approach

In the present review, the authors focus on recent synthesis methods of WO3-based gas sensors to enhance sensing features towards toxic gases.

Findings

This work has proved that the synthesis method led to provide different morphologies of nanostructured WO3-based material in turn to improve gas sensing performance along with its sensing mechanism.

Originality/value

In this work, the authors reviewed challenges and possibilities associated with the nanostructured WO3-based gas sensors to trace toxic gases such as ammonia, H2S and NO2 for future research.

Details

Sensor Review, vol. 41 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 5 January 2022

Thejas Ramakrishnaiah, Prasanna Gunderi Dhananjaya, Chaturmukha Vakwadi Sainagesh, Sathish Reddy, Swaroop Kumaraswamy and Naveen Chikkahanumajja Surendranatha

This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of…

Abstract

Purpose

This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of high-performance electrical and gas sensing materials operating at room temperature.

Design/methodology/approach

PANI/ferrite nanocomposites exhibit good electrical properties with lower dielectric losses. There are numerous reports on PANI and ferrite nanomaterial-based gas sensors which have good sensing response, feasible to operate at room temperature, requires less power and cost-effective.

Findings

This paper provides an overview of electrical and gas sensing properties of PANI/ferrite nanocomposites having improved selectivity, long-term stability and other sensing performance of sensors at room temperature.

Originality/value

The main purpose of this review paper is to focus on PANI/ferrite nanocomposite-based gas sensors operating at room temperature.

Details

Sensor Review, vol. 42 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 19 June 2017

Xuehai Guo, Guofeng Pan, Xin Ma, Xiangzhou Li, Ping He, Zhongqiu Hua and Haiqing Li

The purpose of this research is to synthesize Al2O3-ZnO thick films, study the effect of doping and optical excitation on their sensing properties and introduce an…

Abstract

Purpose

The purpose of this research is to synthesize Al2O3-ZnO thick films, study the effect of doping and optical excitation on their sensing properties and introduce an attractive candidate for acetone detection in practice.

Design/methodology/approach

ZnO nanoparticles doped with Al2O3 were prepared by sol-gel method and characterized via X-ray diffraction and field-emission scanning electron microscopy. The sensing properties to acetone were investigated with an irradiation of UV. The sensing mechanism was also discussed with UV-Vis spectroscopy.

Findings

The doping of Al2O3 promoted the sensing response and stability of ZnO nanoparticles. The optimum performance was obtained by 4.96 Wt.% Al2O3-ZnO. The response to acetone (1,000 ppm) was significantly increased to 241.81, even just at an operating temperature of 64°C. It was also demonstrated that optical excitation with UV irradiation greatly enhanced the sensing response and the sensitivity can reach up to 305.14.

Practical implications

The sensor fabricated from 4.96 Wt.% Al2O3-ZnO exhibited excellent acetone-sensing characteristics. It is promising to be applied in low power and miniature acetone gas sensors.

Originality/value

In the present research, the optimum performance was obtained by 4.96 Wt.% Al2O3-ZnO at a low operating temperature of 64°C. The sensing properties were enhanced significantly with optical excitation, and the sensing mechanism was discussed with UV-Vis spectroscopy which has been reported rarely before.

Details

Sensor Review, vol. 37 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 8 July 2022

Syafiqah Ishak, Shazlina Johari, Muhammad Mahyiddin Ramli and Darminto Darminto

This review aims to give an overview about zinc oxide (ZnO) based gas sensors and the role of doping in enhancing the gas sensing properties. Gas sensors based on ZnO thin…

Abstract

Purpose

This review aims to give an overview about zinc oxide (ZnO) based gas sensors and the role of doping in enhancing the gas sensing properties. Gas sensors based on ZnO thin film are preferred for sensing applications because of their modifiable surface morphology, very large surface-to-volume ratio and superior stability due to better crystallinity. The gas detection mechanism involves surface reaction, in which the adsorption of gas molecules on the ZnO thin film affects its conductivity and reduces its electrical properties. One way to enhance the gas sensing properties is by doping ZnO with other elements. A few of the common and previously used dopants include tin (Sn), nickel (Ni) and gallium (Ga).

Design/methodology/approach

In this brief review, previous works on doped-ZnO formaldehyde sensing devices are presented and discussed.

Findings

Most devices provided good sensing performance with low detection limits. The reported operating temperatures were within the range of 200̊C –400̊C. The performance of the gas sensors can be improved by modifying their nanostructures and/or adding dopants.

Originality/value

As of yet, a specific review on formaldehyde gas sensors based on ZnO metal semiconductors has not been done.

Details

Sensor Review, vol. 42 no. 5
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 8 January 2018

Yuxin Miao, Guofeng Pan, Caixuan Sun, Ping He, Guanlong Cao, Chao Luo, Li Zhang and Hongliang Li

The purpose of this paper is to study the effect of doping, annealing temperature and visible optical excitation on CuO-ZnO nanocomposites’ acetone sensing properties and…

Abstract

Purpose

The purpose of this paper is to study the effect of doping, annealing temperature and visible optical excitation on CuO-ZnO nanocomposites’ acetone sensing properties and introduce an attractive candidate for acetone detection at about room temperature.

Design/methodology/approach

ZnO nanoparticles doped with CuO were prepared by sol-gel method, and the structure and morphology were characterized via X-ray diffraction, scanning electron microscope, energy dispersive spectroscopy and Brunauer-Emmett-Teller. The photoelectric responses of CuO-ZnO nanocomposites to cetone under the irradiation of visible light were investigated at about 30°C. The photoelectric response mechanism was also discussed with the model of double Schottky.

Findings

The doping of CuO enhanced performance of ZnO nanoparticles in terms of the photoelectric responses and the gas response and selectivity to acetone of ZnO nanoparticles, in addition, decreasing the operating temperature to about 30ºC. The optimum performance was obtained by 4.17% CuO-ZnO nanocomposites. Even at the operating temperature, about 30ºC, the response to 1,000 ppm acetone was significantly increased to 579.24 under the visible light irradiation.

Practical implications

The sensor fabricated by 4.17% CuO-ZnO nanocomposites exhibited excellent acetone-sensing characteristics at about 30ºC. It is promising to be applied in low power and miniature acetone gas sensors.

Originality/value

In the present research, a new nanocomposite material of CuO-ZnO was prepared by Sol-gel method. The optimum gas sensing properties to acetone were obtained by 4.17% CuO-ZnO nanocomposites at about 30ºC operating temperature when it was irradiated by visible light with the wavelength more than 420 nm.

Details

Sensor Review, vol. 38 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 10 June 2014

Shaohong Wei, Youjuan Zhang and Meihua Zhou

The purpose of this paper is to synthesize SnO2–ZnO hollow nanofibers, study their sensing properties and introduce an attractive candidate for formaldehyde detection in…

Abstract

Purpose

The purpose of this paper is to synthesize SnO2–ZnO hollow nanofibers, study their sensing properties and introduce an attractive candidate for formaldehyde detection in practice.

Design/methodology/approach

Pure and SnO2–ZnO hollow nanofibers were synthesized by electrospinning method and characterized via X-ray diffraction, field-emission scanning electron microscopy and Fourier transform infrared spectroscopy. The formaldehyde-sensing properties were investigated.

Findings

The optimum performance was obtained at 260°C by the 14 at.% SnO2–ZnO hollow nanofiber sensor. The sensor could detect formaldehyde down to 0.1 ppm with rapid response–recovery time (4-6 s and 7-9 s, respectively), high sensitivity, good selectivity and stability. The relationship between the sensor’s sensitivity and formaldehyde concentration suggests that the adsorbed oxygen species on the sensor’s surface is O2−. The prominent sensing properties are attributed to the one dimensional hollow nanofiber structures and the promoting effects of SnO2.

Practical implications

The sensor fabricated from 14 at.% SnO2–ZnO fibers exhibits excellent formaldehyde-sensing characteristics. It can be used for formaldehyde detection in practice.

Social implications

The electrospinning method is a very simple and convenient method for fabricating hollow nanofibers and the sensing material is of low cost.

Originality/value

To the best of the authors’ knowledge, studies on formaldehyde sensing of SnO2–ZnO hollow nanofibers have not been reported before.

Details

Sensor Review, vol. 34 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 15 April 2020

Bassam Abdallah, Mahmoud Kakhia and Walaa Zetoune

This study aims to carry out the deposition of zinc sulfide (ZnS) thick films on glass and silicon (100) substrates using radio frequency (RF) magnetron sputtering method…

Abstract

Purpose

This study aims to carry out the deposition of zinc sulfide (ZnS) thick films on glass and silicon (100) substrates using radio frequency (RF) magnetron sputtering method at different powers. Film structure has been analyzed by X-ray diffraction (XRD); the patterns showed that the films possesses a cubic structure with (111) preferred orientation. Photoluminance (PL) intensity of the films has been related to the crystallinity, which is varied with the power.

Design/methodology/approach

Scanning electron microscope (SEM) images have been used to discover the films’ morphology. The stoichiometry has been confirmed by energy dispersive X-ray spectroscopy (EDX) analysis. MicroRaman spectroscopy has been used to validate the film structure. Gas-sensing studies were carried out by means of a static gas chamber to sense acetone, ethanol, methanol, H2O and NH3 vapor in air ambient.

Findings

ZnS has a stoichiometric and cubic structure. The band gaps and photoluminance intensity of the films are correlated with the crystallinity, which is varied with the power. The EDX analysis approved the stoichiometry of the prepared films. Acetone, ethanol, humidity (H2O), methanol and NH3 vapor gases were used to justify the sensing properties at 25°C of the thickest ZnS film.

Originality/value

High-quality ZnS films have been obtained at different powers without annealing. Gases sensing properties at 25°C are justified for deposited ZnS films using acetone, ethanol, humidity (H2O), methanol and NH3 vapor gases. It reveals good response for NH3 and humidity vapors at room temperature; the sensing functioning at this temperature was attractive in recent research.

Details

World Journal of Engineering, vol. 17 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 20 March 2017

Md.Masud Rana, Dauda Sh. Ibrahim, M.R. Mohd Asyraf, S. Jarin and Amanullah Tomal

This review paper aims to focus on recent advances of carbon nanotubes (CNTs) to produce gas sensors. Gas sensors are widely used for monitoring hazardous gas leakages and…

2480

Abstract

Purpose

This review paper aims to focus on recent advances of carbon nanotubes (CNTs) to produce gas sensors. Gas sensors are widely used for monitoring hazardous gas leakages and emissions in the industry, households and other areas. For better safety and a healthy environment, it is highly desirable to have gas sensors with higher accuracy and enhanced sensing features.

Design/methodology/approach

In this review, the authors focus on recent contributions of CNTs to the technology for developing different types of gas sensors. The design, fabrication process and sensing mechanism of each gas sensor are summarized, together with their advantages and disadvantages.

Findings

Nowadays, CNTs are well-known materials which have attracted a significant amount of attention owing to their excellent electrical, electronic and mechanical properties. On exposure to various gases, their properties allow the detection of gases using different methods. Therefore, over recent years, researchers have developed several different types of gas sensors along with other types of sensors for temperature, strain, pressure, etc.

Originality/value

The main purpose of this review is to introduce CNTs as candidates for future research in the field of gas sensing applications and to focus on current technical challenges associated with CNT-based gas sensors.

Details

Sensor Review, vol. 37 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 5 December 2017

Mohammadali Eslamian, Alireza Salehi and Zohreh Sadat Miripour

Indium tin oxide (ITO) thin film as a gas sensor has a good stability and performance. The purpose of this paper is to compare the effect of depositing different metal…

165

Abstract

Purpose

Indium tin oxide (ITO) thin film as a gas sensor has a good stability and performance. The purpose of this paper is to compare the effect of depositing different metal layers in various structures on the gas sensing properties of ITO toward ethanol and carbon dioxide.

Design/methodology/approach

In this work, the authors have investigated the effect of depositing an ITO layer by Electron Beam Evaporation technique under, on top and in the middle of the metal layers. Surface morphology and the response of the fabricated sensors were compared and the changes in the response of the sensors to ethanol and carbon dioxide gases were studied at various gas concentrations and operating temperatures. The sensing mechanism and result of the other studies were also discussed.

Findings

Comparing various sensor structures reported in this study showed that the ITO nanorods which grow over distinct Ag nano-islands in the ITO/Ag structure has the highest response of 420 per cent to ethanol which is 6 times more than the single-layer ITO sensor. Further, gold nanoparticles on ITO nanorods in Au/ITO/Ag structure produce a very complex structure that exhibits the best response of 150 per cent to carbon dioxide which is 6.5 times more than the single-layer ITO sensor. The response and the recovery times were improved also.

Originality/value

Different ITO-metal gas sensor structures were studied and compared toward ethanol and carbon dioxide. Response enhancement and various surface changes through a series of experiments and analysis were discussed and compared to the literature.

Details

Sensor Review, vol. 38 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 14 January 2014

Robert Bogue

– This paper aims to provide a detailed review of gas sensor research which exploits the properties of nanomaterials and nanostructures.

1882

Abstract

Purpose

This paper aims to provide a detailed review of gas sensor research which exploits the properties of nanomaterials and nanostructures.

Design/methodology/approach

Following an introduction, this paper discusses developments in gas sensors based on carbon nanotubes, titanium dioxide nanotubes, graphene, nanocrystalline diamond and a range of metal oxide nanomaterials. It concludes with a discussion of this research and its commercial potential and a list of references to the research considered in the main text.

Findings

Gas sensors based on a multitude of nanomaterials are the subject of a global research effort which has generated an extensive literature. Prototype devices have been developed which respond to numerous important gases at concentrations which correspond well with industrial requirements. Other critical performance characteristics have been studied extensively and the results suggest commercial prospects for these technologies.

Originality/value

This paper provides details of the highly topical field of nanomaterial-based gas sensor research.

Details

Sensor Review, vol. 34 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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