Highly selective ppb-level detection of NH3 and NO2 gas using patterned porous channels of ITO nanoparticles

Lee, Dong Jin; Park, Jonghyurk; Kim, Hyun Soo; Lee, Dong Hoon; Park, Minjun; Chang, Hochan; Jin, Joon-Hyung; Sohn, Jong Ryeul; Heo, Kwang; Lee, Byung Yang

doi:10.1016/j.snb.2015.04.057

Cited by 20 publications

(13 citation statements)

References 35 publications

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“…As a result, the resistance of Co 3 O 4 /SnO 2 increased greatly (Figure S8a). However, when the gas sensor was exposed to NH 3 , the subsequent reaction releases electrons (2NH 3 + 3O – → N 2 + 3H 2 O + 3e – ) , into the conduction bands of SnO 2 and Co 3 O 4 , reducing the width of the depletion layer and decreasing the height of the potential barrier and resulting in a decrease of the resistance of Co 3 O 4 /SnO 2 -based gas sensors (Figure S8b). , Thus, the fabrication of hybrid composite materials with a unique structure is an effective strategy to improving the gas-sensor performance.…”

Section: Results and Discussionmentioning

confidence: 99%

Hybrid Co₃O₄/SnO₂ Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Wang

Lou

Zhang

et al. 2016

ACS Appl. Mater. Interfaces

157

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Novel hybrid Co3O4/SnO2 core-shell nanospheres have been effectively realized by a one-step hydrothermal, template-free preparation method. Our strategy involves a simple fabrication scheme that entails the coating of natural cross-link agents followed by electrostatic interaction between the positive charges of Sn and Co ions and the negative charge of glutamic acid. The core-shell architecture enables novel flexibility of gas sensor surfaces compared to commonly used bulk materials. The highly efficient charge transfer and unique structure are key to ensuring the availability of high response and rapid-response speed. It demonstrates how hybrid core-shell nanospheres can be used as an advance function material to fabricate electrical sensing devices that may be useful as gas sensors.

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Section: Results and Discussionmentioning

confidence: 99%

Hybrid Co₃O₄/SnO₂ Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Wang

Lou

Zhang

et al. 2016

ACS Appl. Mater. Interfaces

157

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“…The surrounding OTS regions are non-polar due to the methyl terminals of the OTS molecules. The NWs are thought to get adsorbed only on the polar SiO 2 regions by van der Waals interaction [40]. The selective assembly of ZnO NWs was also confirmed with energy-dispersive X-ray spectroscopy (EDS) (see Additional file 1: Figure S2).…”

Section: Resultsmentioning

confidence: 81%

“…The NWs were dispersed to 1 wt% concentration in dichlorobenzene (DCB) by sonication for 3 s. For preparing the molecularly patterned substrates, photoresist (AZ 5214E) was patterned on SiO2 (300-nm-thick SiO2 on 500-μm-thick p-doped Si wafer) substrate by typical photolithography method. Then, the substrate was dipped into 1:500 v / v octadecyltrichlorosilane (OTS) in hexane about 3 min [40]. During this process, a monolayer of OTS molecules was self-assembled on the surface of the exposed SiO 2 region to create a non-polar OTS region.…”

Section: Methodsmentioning

confidence: 99%

Facile fabrication of self-assembled ZnO nanowire network channels and its gate-controlled UV detection

et al. 2018

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We demonstrate a facile way to fabricate an array of gate-controllable UV sensors based on assembled zinc oxide nanowire (ZnO NW) network field-effect transistor (FET). This was realized by combining both molecular surface programmed patterning and selective NW assembly on the polar regions avoiding the nonpolar regions, followed by heat treatment at 300 °C to ensure stable contact between NWs. The ZnO NW network FET devices showed typical n-type characteristic with an on-off ratio of 105, transconductance around 47 nS, and mobility around 0.175 cm2 V− 1 s− 1. In addition, the devices showed photoresponsive behavior to UV light that can be controlled by the applied gate voltage. The photoresponsivity was found to be linearly proportional to the channel voltage Vds, showing maximum photoresponsivity at Vds = 7 V.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2774-0) contains supplementary material, which is available to authorized users.

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“…Direct ammonia slip is another technological threat, which requires NH 3 detection in air in a wide range of concentrations . The applicability of semiconductor metal oxides for these purposes has been demonstrated . However, practical implementation of such sensors is hampered by the instability of response and the influence of interfering gases.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Lewis Acidity of Cr‐Doped Nanocrystalline SnO₂: Effect on Surface NH₃ Oxidation and Sensory Detection Pattern

et al. 2019

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Understanding ammonia oxidation over metal oxide surfaces is crucial for improving its detection with resistive type gas sensors. Formation of NOx during this process makes sensor response and calibration unstable. Cr‐doping of nanocrystalline metal oxides has been reported to suppress NO2 sensitivity and improve response towards NH3, however the exact mechanism of such chromium action remained unknown. Herein, by using EPR spectroscopy we demonstrate formation of Cr(VI) lattice defects on the surface of nanocrystalline Cr‐doped SnO2. Enhancement of Cr‐doped SnO2 surface acidity and ammonia adsorption as a result has been revealed by using in situ IR spectroscopy. Moreover, a decrease in concentration of free electrons in the conduction band has been shown as a result of substitutional Cr(III) defects formation. Weaker NOx chemisorption during ammonia oxidation over SnO2 surface after Cr doping has been found with the use of mass‐spectrometry assisted NH3 thermo‐programmed desorption. The given example of surface acidity adjustment and electronic configuration by means of doping may find use in the design of new gas‐sensing metal oxide materials.

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Highly selective ppb-level detection of NH3 and NO2 gas using patterned porous channels of ITO nanoparticles

Cited by 20 publications

References 35 publications

Hybrid Co₃O₄/SnO₂ Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Hybrid Co₃O₄/SnO₂ Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Facile fabrication of self-assembled ZnO nanowire network channels and its gate-controlled UV detection

Enhancement of Lewis Acidity of Cr‐Doped Nanocrystalline SnO₂: Effect on Surface NH₃ Oxidation and Sensory Detection Pattern

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Highly selective ppb-level detection of NH3 and NO2 gas using patterned porous channels of ITO nanoparticles

Cited by 20 publications

References 35 publications

Hybrid Co3O4/SnO2 Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Hybrid Co3O4/SnO2 Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Facile fabrication of self-assembled ZnO nanowire network channels and its gate-controlled UV detection

Enhancement of Lewis Acidity of Cr‐Doped Nanocrystalline SnO2: Effect on Surface NH3 Oxidation and Sensory Detection Pattern

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Product

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Hybrid Co₃O₄/SnO₂ Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Hybrid Co₃O₄/SnO₂ Core–Shell Nanospheres as Real-Time Rapid-Response Sensors for Ammonia Gas

Enhancement of Lewis Acidity of Cr‐Doped Nanocrystalline SnO₂: Effect on Surface NH₃ Oxidation and Sensory Detection Pattern