Fabrication of Fe doped reduced graphene oxide (rGO) decorated WO3 based low temperature ppm level acetone sensor: Unveiling sensing mechanism by impedance spectroscopy

Sen, Sovandeb; Maity, Sourav; Kundu, Susmita

doi:10.1016/j.snb.2022.131706

Cited by 24 publications

(6 citation statements)

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“…Due to the work function of ZnO (4.3 eV) being lower than that of WO 3 (5.8 eV), , when contact between ZnO and WO 3 occurs, a grain boundary barrier exists at the interface between ZnO nanorods and WO 3 nanosheets, forming an n–n isotype heterojunction, causing the energy band to bend upwards and transferring electrons from ZnO to WO 3 until the two Fermi energy levels reach equilibrium, which forms an electron depletion layer on the surface of ZnO and WO 3 . The grain boundary barrier has been proven to be a stimulus for the enhancement of gas sensing performance. , When ZnO/WO 3 sensors contact air, O 2 molecules adsorb to the material surface and capture electrons from the ZnO conduction band to form negative oxygen species (O 2 – , O – , and O 2– ), with O – being the predominant adsorbed oxygen species at an optimum operating temperature of 180 °C . When exposed to a NO 2 atmosphere, NO 2 adsorbs on the surfaces of ZnO and WO 3 and captures electrons from their conduction bands to form NO 2 – , subsequently, the adsorbed NO 2 – (ads) ions react with the adsorbed O – ions, which results in the formation of a thick electron depletion layer on the surfaces of ZnO and WO 3 , thereby leading to a sharp increase in material resistance.…”

Section: Resultsmentioning

confidence: 99%

“…51,52 When ZnO/ WO 3 sensors contact air, O 2 molecules adsorb to the material ), with O − being the predominant adsorbed oxygen species at an optimum operating temperature of 180 °C. 53 When exposed to a NO 2 atmosphere, NO 2 adsorbs on the surfaces of ZnO and WO 3 and captures electrons from their conduction bands to form NO 2 − , subsequently, the adsorbed NO 2 − (ads) ions react with the adsorbed O − ions, which results in the formation of a thick electron depletion layer on the surfaces of ZnO and WO 3 , thereby leading to a sharp increase in material resistance. The specific reaction equation is shown below 54 NO NO…”

Section: Structure and Morphology Of As-preparedmentioning

confidence: 99%

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Heterojunctions of ZnO-Nanorod-Decorated WO₃ Nanosheets Coated with ZIF-71 for Humidity-Independent NO₂ Sensing

Qian,

Fang,

Gui

et al. 2023

ACS Appl. Nano Mater.

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NO2 is a very dangerous and toxic gas and is prone to cause acid rain in high humidity environments, so it is essential to prepare a real-time monitoring and humidity immunity NO2 sensor. WO3 nanomaterials are commonly applied to detect NO2, but their poor immunity to humidity is still a critical limitation for the application. ZnO-nanorod-decorated WO3 nanosheets coated with ZIF-71 (ZnO@ZIF-71/WO3) composites prepared by an in situ growth method displayed excellent gas sensing performance and good humidity immunity to detect NO2. Compared to WO3 nanosheets and ZnO-nanorod-decorated WO3 nanosheets (ZnO/WO3) heterojunction composites grown on ceramic substrates in situ, ZnO@ZIF-71/WO3 presented excellent selectivity, good long-term stability, and a remarkably high response of about 947.96 to 100 ppm NO2 at 180 °C, which is 3.07 times higher than that of the ZnO/WO3 sensor and 4.59 times higher than that of the pure WO3 sensor. Even at a relative humidity of 85%, the response of ZnO@ZIF-71/WO3 to NO2 remained essentially constant. The functional ZIF-71 layer not only improved the humidity immunity of ZnO@ZIF-71/WO3 but also enhanced the sensitivity and selectivity performance to NO2 at low operating temperatures. The ZnO@ZIF-71/WO3 sensor still provided a response of 88.41 to 100 ppm NO2 at room temperature.

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Section: Resultsmentioning

confidence: 99%

Section: Structure and Morphology Of As-preparedmentioning

confidence: 99%

Heterojunctions of ZnO-Nanorod-Decorated WO₃ Nanosheets Coated with ZIF-71 for Humidity-Independent NO₂ Sensing

Qian,

Fang,

Gui

et al. 2023

ACS Appl. Nano Mater.

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“… [ 99 ] The Fe doping of WO 3 increased the response to 10 ppm acetone from 1.2% for pure WO 3 to 78% for Fe doped WO 3 at 130 °C, as evidenced by the experimental data. [ 100 ] Ho 3+ The 3 mol% Ho-doped WO 3 sensor exhibited a 5-fold increase in acetone sensitivity compared to pure WO 3 , with maximum response of 15.2–100 ppm acetone at 200 °C. [ 101 ] In The 5 wt% In-doped WO 3 sensor exhibited an 11.2-fold increase in response to 50 ppm TEA at 115 °C compared to pure WO 3 .…”

Section: Strategies For Improving Wo 3 Gas Sensor ...mentioning

confidence: 99%

Innovations in WO3 gas sensors: Nanostructure engineering, functionalization, and future perspectives

Li,

Fu,

Karimi-Maleh

et al. 2024

Heliyon

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“…Excellent selectivity, adequate reproducibility and stability. Limit of detection: 1 ppm [113] Various morphologies of WO 3 (spheres, nanorods, flowers and sea urchins)…”

Section: Materials Used For the Development Of Wo 3 -Based Sensors Re...mentioning

confidence: 99%

The Role of Nano-Sensors in Breath Analysis for Early and Non-Invasive Disease Diagnosis

Lagopati,

Valamvanos,

Proutsou

et al. 2023

Chemosensors

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Early-stage, precise disease diagnosis and treatment has been a crucial topic of scientific discussion since time immemorial. When these factors are combined with experience and scientific knowledge, they can benefit not only the patient, but also, by extension, the entire health system. The development of rapidly growing novel technologies allows for accurate diagnosis and treatment of disease. Nanomedicine can contribute to exhaled breath analysis (EBA) for disease diagnosis, providing nanomaterials and improving sensing performance and detection sensitivity. Through EBA, gas-based nano-sensors might be applied for the detection of various essential diseases, since some of their metabolic products are detectable and measurable in the exhaled breath. The design and development of innovative nanomaterial-based sensor devices for the detection of specific biomarkers in breath samples has emerged as a promising research field for the non-invasive accurate diagnosis of several diseases. EBA would be an inexpensive and widely available commercial tool that could also be used as a disease self-test kit. Thus, it could guide patients to the proper specialty, bypassing those expensive tests, resulting, hence, in earlier diagnosis, treatment, and thus a better quality of life. In this review, some of the most prevalent types of sensors used in breath-sample analysis are presented in parallel with the common diseases that might be diagnosed through EBA, highlighting the impact of incorporating new technological achievements in the clinical routine.

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Fabrication of Fe doped reduced graphene oxide (rGO) decorated WO3 based low temperature ppm level acetone sensor: Unveiling sensing mechanism by impedance spectroscopy

Cited by 24 publications

References 78 publications

Heterojunctions of ZnO-Nanorod-Decorated WO₃ Nanosheets Coated with ZIF-71 for Humidity-Independent NO₂ Sensing

Heterojunctions of ZnO-Nanorod-Decorated WO₃ Nanosheets Coated with ZIF-71 for Humidity-Independent NO₂ Sensing

Innovations in WO3 gas sensors: Nanostructure engineering, functionalization, and future perspectives

The Role of Nano-Sensors in Breath Analysis for Early and Non-Invasive Disease Diagnosis

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Fabrication of Fe doped reduced graphene oxide (rGO) decorated WO3 based low temperature ppm level acetone sensor: Unveiling sensing mechanism by impedance spectroscopy

Cited by 24 publications

References 78 publications

Heterojunctions of ZnO-Nanorod-Decorated WO3 Nanosheets Coated with ZIF-71 for Humidity-Independent NO2 Sensing

Heterojunctions of ZnO-Nanorod-Decorated WO3 Nanosheets Coated with ZIF-71 for Humidity-Independent NO2 Sensing

Innovations in WO3 gas sensors: Nanostructure engineering, functionalization, and future perspectives

The Role of Nano-Sensors in Breath Analysis for Early and Non-Invasive Disease Diagnosis

Contact Info

Product

Resources

About

Heterojunctions of ZnO-Nanorod-Decorated WO₃ Nanosheets Coated with ZIF-71 for Humidity-Independent NO₂ Sensing

Heterojunctions of ZnO-Nanorod-Decorated WO₃ Nanosheets Coated with ZIF-71 for Humidity-Independent NO₂ Sensing