Drastically Enhanced Ammonia Sensing of Pt/ZnO Ordered Porous Ultra-Thin Films

Li, Zhou; Yi, Jianxin

doi:10.1016/j.snb.2020.128217

Cited by 46 publications

(28 citation statements)

References 45 publications

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“…The specific oxygen species and their relative amount have a remarkable influence on the reaction capacity of one material with target gas molecules . In view of this, the O 1s core level spectra for pure ZnO and C10–ZnO to C16–ZnO were thoroughly deconvoluted, and the fitted data are exhibited in Figures S6 and S5c–f, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…ZnO as well as SnO 2 are the first sensing materials used in SMO-based gas sensors. In particular, ZnO is a polar crystal that fails to achieve a perfect stoichiometric ratio. , Generally, there exist natural dominant defects composed of zinc interstitials (Zn i ) and oxygen vacancies (V O ) as electron donors in ZnO crystals. , There exist additional intrinsic defects, such as oxygen interstitials (O i ), zinc vacancies (V Zn ), and zinc/oxygen antisites (Zn O /O Zn ). , Given these unique advantages, a multitude of ZnO nanostructures have been exploited to detect almost all kinds of harmful gases, such as volatile organic compounds (VOCs), NH 3 , H 2 S, SO 2 , CO, H 2 , NO 2 , etc. However, although these ZnO-based gas sensors exhibit good gas-sensing properties, they usually only work at high temperatures.…”

Section: Introductionmentioning

confidence: 99%

“…10,11 There exist additional intrinsic defects, such as oxygen interstitials (O i ), zinc vacancies (V Zn ), and zinc/oxygen antisites (Zn O /O Zn ). 10,11 Given these unique advantages, a multitude of ZnO nanostructures have been exploited to detect almost all kinds of harmful gases, such as volatile organic compounds (VOCs), 12 NH 3 , 13 H 2 S, 14 SO 2 , 15 CO, 16 H 2 , 17 NO 2 , 18 etc. However, although these ZnO-based gas sensors exhibit good gas-sensing properties, they usually only work at high temperatures.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO₂ Gas Sensing

Zhang

Xia

Zhang

et al. 2022

ACS Appl. Nano Mater.

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The oriented design and controllable preparation of sensing materials are extremely important and meaningful attributes that not only contribute to the realization of desirable gas-sensing properties but also facilitate the validation of the sensing mechanism. Because of the spatial effect derived from micelle assemblies formed by surfactant molecules under certain circumstances, radial growth of ZnO crystals is successfully suppressed in this work, which leads to the formation of ZnO nanowires with a larger aspect ratio. Furthermore, anionic surfactants of the same series but with longer carbon chains were utilized to create a greater spatial effect, which leads to more serious radial inhibition and, eventually, ever-increasing aspect ratios for the products. Except for a change in morphology, multiple characterization methods, such as XRD, FT-IR, and XPS, confirm the in situ doping/functionalization of surfactant molecules into ZnO crystals during the preparation process, which, on one hand, provide important evidence for the analysis of the product formation mechanism, and, on the other hand, serve as active sites for light-enhanced sensing. In subsequent gas-sensing tests, all surfactant−induced ZnO samples were applied as sensing materials to detect NO 2 at room temperature (RT, 25 °C) in the dark, which show an increased response with increasing aspect ratio. In particular, at RT, the response toward 10 ppm NO 2 of C16−ZnO with the highest aspect ratio reaches 271% in the dark, which is 24.64 times higher than that of pure ZnO without surfactant-assisted synthesis. Under UV irradiation, the response of C16−ZnO toward 10 ppm NO 2 is further enhanced to 602% at RT, and this magnitude (2.22 times) of response improvement compared with that in the dark is maximal among all surfactant−induced ZnO samples. Moreover, the response/recovery time of C16−ZnO toward 10 ppm NO 2 at RT is found to be drastically decreased from 393/953 s in the dark to 58/91 s under UV irradiation.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO₂ Gas Sensing

Zhang

Xia

Zhang

et al. 2022

ACS Appl. Nano Mater.

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“…NH3 molecule reacts with the adsorbed ions of oxygen, causing the release of the trapped electrons and narrowing the space charge [51]. The adsorption of NH3 is enhanced by the transfer of charge due to the presence of oxygen ions on the AGNR surface which may be presented as [52]:…”

Section: The Detailed Description Of the Different Examined Nanostruc...mentioning

confidence: 99%

Adsorption of Ammonia on Zrox Modified Graphene Nanoribbon: A First-Principles Investigation

Ayesh

2022

SSRN Journal

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“…Therefore, the detection and early warning of ammonia gas is necessary. Since ammonia gas applications are usually in a harsh environment such as corrosive, traditional electrochemical sensors are widely used due to their high measurement accuracy [ 2 , 3 , 4 , 5 ], but have many shortcomings such as short life, easy contamination and poor repeatability. A sensor capable of overcoming the above disadvantages and capable of performing timely, effective and stable ammonia gas detection is undoubtedly a research hotspot.…”

Section: Introductionmentioning

confidence: 99%

Ammonia Gas Sensor Based on Graphene Oxide-Coated Mach-Zehnder Interferometer with Hybrid Fiber Structure

Fan

Deng

Wei

et al. 2021

Sensors

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A graphene oxide-coated in-fiber Mach-Zehnder interferometer (MZI) formed with a multimode fiber-thin core fiber-multimode fiber (MMF-TCF-MMF) is proposed and experimentally demonstrated for ammonia gas (NH3) sensing. The MZI structure is composed of two segments of MMF of length 2 mm, with a flame-tapered TCF between them as the sensing arm. The MMFs act as mode couplers to split and recombine light owing to the core diameter mismatch with the other fibers. A tapered TCF is formed by the flame melting taper method, resulting in evanescent wave leakage. A layer of graphene oxide (GO) is applied to the tapered region of the TCF to achieve gas adsorption. The sensor operates on the principle of changing the effective refractive index of the cladding mode of a fiber through changing the conductivity of the GO coating by adsorbed NH3 molecules, which gives rise to a phase shift and shows as the resonant dip shifts in the transmission spectrum. So the concentration of the ammonia gas can be obtained by measuring the dip shift. A wavelength-shift sensitivity of 4.97 pm/ppm with a linear fit coefficient of 98.9% is achieved for ammonia gas concentrations in the range of 0 to 151 ppm. In addition, we performed a repetitive dynamic response test on the sensor by charging/releasing NH3 at concentration of 200 ppm and a relative humidity test in a relative humidity range of 35% to 70%, which demonstrates the reusability and stability of the sensor.

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Drastically Enhanced Ammonia Sensing of Pt/ZnO Ordered Porous Ultra-Thin Films

Cited by 46 publications

References 45 publications

ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO₂ Gas Sensing

ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO₂ Gas Sensing

Adsorption of Ammonia on Zrox Modified Graphene Nanoribbon: A First-Principles Investigation

Ammonia Gas Sensor Based on Graphene Oxide-Coated Mach-Zehnder Interferometer with Hybrid Fiber Structure

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Drastically Enhanced Ammonia Sensing of Pt/ZnO Ordered Porous Ultra-Thin Films

Cited by 46 publications

References 45 publications

ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO2 Gas Sensing

ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO2 Gas Sensing

Adsorption of Ammonia on Zrox Modified Graphene Nanoribbon: A First-Principles Investigation

Ammonia Gas Sensor Based on Graphene Oxide-Coated Mach-Zehnder Interferometer with Hybrid Fiber Structure

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Product

Resources

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ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO₂ Gas Sensing

ZnO Nanowires with Increasing Aspect Ratios for Room-Temperature NO₂ Gas Sensing