NO2 sensing properties of porous Au-incorporated tungsten oxide thin films prepared by solution process

Kim, Tae Hoon; Hasani, Amirhossein; Quyet, Le Van; Kim, Yeon Hoo; Park, Seo Yun; Lee, Mi Gyoung; Sohn, Woonbae; Nguyen, Thang Phan; Choi, Kyoung Soon; Kim, Soo Young; Jang, Ho Won

doi:10.1016/j.snb.2019.02.009

Cited by 52 publications

(34 citation statements)

References 72 publications

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“…The addition of precious metals to WO 3 is performed to improve the gas-sensor interaction, as well as the response and recovery times, and decrease the operating temperature. Gold is the most represented metal in the recently reported works, probably because Au-doped WO 3 -based sensors exhibit overall enhancement in NO 2 sensing performances (response, detection limit and response/recovery times) [317,318] but also because they are only slightly affected by humidity. In fact, measurement in a humid atmosphere is one drawback of the semiconductor oxide-based sensors, and WO 3 is no exception [319].…”

Section: Wo 3 -Based Sensor For No 2 Detectionmentioning

confidence: 99%

Tungsten-Based Catalysts for Environmental Applications

2021

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This review aims to give a general overview of the recent use of tungsten-based catalysts for wide environmental applications, with first some useful background information about tungsten oxides. Tungsten oxide materials exhibit suitable behaviors for surface reactions and catalysis such as acidic properties (mainly Brønsted sites), redox and adsorption properties (due to the presence of oxygen vacancies) and a photostimulation response under visible light (2.6–2.8 eV bandgap). Depending on the operating condition of the catalytic process, each of these behaviors is tunable by controlling structure and morphology (e.g., nanoplates, nanosheets, nanorods, nanowires, nanomesh, microflowers, hollow nanospheres) and/or interactions with other compounds such as conductors (carbon), semiconductors or other oxides (e.g., TiO2) and precious metals. WOx particles can be also dispersed on high specific surface area supports. Based on these behaviors, WO3-based catalysts were developed for numerous environmental applications. This review is divided into five main parts: structure of tungsten-based catalysts, acidity of supported tungsten oxide catalysts, WO3 catalysts for DeNOx applications, total oxidation of volatile organic compounds in gas phase and gas sensors and pollutant remediation in liquid phase (photocatalysis).

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Section: Wo 3 -Based Sensor For No 2 Detectionmentioning

confidence: 99%

Tungsten-Based Catalysts for Environmental Applications

2021

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“…MOS gas sensors are considered to be one of the most common materials for determining and measuring the concentration of gases in a combustion atmosphere . These MOS gas sensor devices offer an extensive variety of advantages over conventional analytical devices, such as low cost, short response time, easy fabrication process, and compact size . Despite these qualities, sufficient selectivity in MOS gas sensors has not been demonstrated.…”

Section: Chemoresistive Materials For E‐nosementioning

confidence: 99%

“…Metal oxides are weak in selectivity because they are sensitive simultaneously to reducing and oxidizing gases. Recently, certain methods to improve semiconductor metal oxide (SMO) selectivity, for example, (a) improving selectivity by doping metal oxides with catalytic metal, and (b) applying them to specific devices such as the Karlsruher Mikronase (KAMINA) platform were successfully employed. The implementation of an array of MOS sensors combined with appropriate pattern recognition and classification tools is one of the most promising approaches to compensate for this drawback.…”

Section: Chemoresistive Materials For E‐nosementioning

confidence: 99%

“…51,[60][61][62] These MOS gas sensor devices offer an extensive variety of advantages over conventional analytical devices, such as low cost, short response time, easy fabrication process, and compact size. [63][64][65] Despite these qualities, sufficient selectivity in MOS gas sensors has not been demonstrated. Metal oxides are weak in selectivity because they are sensitive simultaneously to reducing and oxidizing gases.…”

Section: Metal Oxidesmentioning

confidence: 99%

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Chemoresistive materials for electronic nose: Progress, perspectives, and challenges

Park

Kim

et al. 2019

InfoMat

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151

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An electronic nose (e‐nose) is a device that can detect and recognize odors and flavors using a sensor array. It has received considerable interest in the past decade because it is required in several areas such as health care, environmental monitoring, industrial applications, automobile, food storage, and military. However, there are still obstacles in developing a portable e‐nose that can be used for a wide variety of applications. For practical applications of an e‐nose, it is necessary to collect a massive amount of data from various sensing materials that can transduce interactions with molecules reliably and analyze them via pattern recognition. In addition, the possibility of miniaturizing the e‐nose and operating it with low power consumption should be considered. Moreover, it should work efficiently over a long period of time. To satisfy these requirements, several different chemoresistive material platforms including metal oxides, organics such as polymers and carbon‐based materials, and two‐dimensional materials were investigated as sensor elements for an e‐nose. As an individual material has limited selectivity, there is a continuing effort to improve the selectivity and gas sensing properties through surface decoration and compositional and structural variations. To produce a reliable e‐nose, which can be used for practical applications, researches in various fields have to be harmonized. This paper reviews the progress of research on e‐noses based on a chemoresistive gas sensor array and discusses the inherent challenges and potential solutions.

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“…One of the most widely studied material happens to be WO 3 for its high selectivity for gas species like NO 2 . [ 2–6 ] Multiple sensing mechanisms for WO 3 have been reported but the cross‐sensitivity and baseline drift issue introduced by the presence of humidity in the atmosphere has rendered the entire concept of gas sensing in metal oxides elusive. The basic mechanism for gas sensing has already been established as the bonding of the oxygen atoms onto the surface of semiconductor films, wherein the oxygen atoms extract an electron from the conduction band leading to a decrease or increase in resistance for a p‐type or n‐type semiconductor, respectively.…”

Section: Introductionmentioning

confidence: 99%

Reduction of Humidity Effect in WO₃ Thin Film‐Based NO₂ Sensor Using Physiochemical Optimization

Ghosh

Ilango

Prajapati

et al. 2020

Crystal Research and Technology

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In this work, the effect of humidity on WO3 thin films is studied. Two thin films of higher and lower oxidation states are characterized and studied for their interaction with water molecules on the metal oxide sensing surface. The film with higher oxidation is found to be more immune to humidity effect and hence, further used to reduce the same effect using absorbent filters and Nichrome deposited heater mesh. With the use of a Nichrome heater mesh, by increasing mesh temperature from 30 to 90 °C, there is a 63% reduction in absolute humidity at the sensor die. This in turn stabilizes the NO2 sensor response, by decreasing the humidity dependent (40% RH to 90% RH) peak current variation for 3 ppm NO2 exposure, from 65% to 26%. High‐temperature ageing at a temperature of 90 °C and 90% RH is found to be effective in significantly reducing humidity effect on sensor current output and only 8.4% change in peak current is observed for 3 ppm NO2 at variable humidity, which stabilizes the sensor current drift due to humidity variation.

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NO2 sensing properties of porous Au-incorporated tungsten oxide thin films prepared by solution process

Cited by 52 publications

References 72 publications

Tungsten-Based Catalysts for Environmental Applications

Tungsten-Based Catalysts for Environmental Applications

Chemoresistive materials for electronic nose: Progress, perspectives, and challenges

Reduction of Humidity Effect in WO₃ Thin Film‐Based NO₂ Sensor Using Physiochemical Optimization

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NO2 sensing properties of porous Au-incorporated tungsten oxide thin films prepared by solution process

Cited by 52 publications

References 72 publications

Tungsten-Based Catalysts for Environmental Applications

Tungsten-Based Catalysts for Environmental Applications

Chemoresistive materials for electronic nose: Progress, perspectives, and challenges

Reduction of Humidity Effect in WO3 Thin Film‐Based NO2 Sensor Using Physiochemical Optimization

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Product

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Reduction of Humidity Effect in WO₃ Thin Film‐Based NO₂ Sensor Using Physiochemical Optimization