Highly Sensitive p + n Metal Oxide Sensor Array for Low-Concentration Gas Detection

Nowadays, despite the easy fabrication and low cost of metal oxide gas sensors, it is still challenging for them to detect gases at low concentrations. In this study, resistance-matched p-type Cu2O and n-type Ga-doped ZnO, as well as p-type CdO/LaFeO3 and n-type CdO/Sn-doped ZnO sensors were prepared and integrated into p + n sensor arrays to enhance their gas-sensing performance. The materials were characterized by scanning electron microscopy, transmittance electron microscopy, and X-ray diffractometry, and gas-sensing properties were measured using ethanol and acetone as probes. The results showed that compared with individual gas sensors, the response of the sensor array was greatly enhanced and similar to the gas response product of the p- and n-type gas sensors. Specifically, the highly sensitive CdO/LaFeO3 and CdO/Sn-ZnO sensor array had a high response of 21 to 1 ppm ethanol and 14 to 1 ppm acetone, with detection limits of <0.1 ppm. The results show the effect of sensor array integration by matching the two sensor resistances, facilitating the detection of gas at a low concentration.

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Cocaine by-product detection with metal oxide semiconductor sensor arrays

RSC Advances ◽

10.1039/d0ra03687k ◽

2020 ◽

Vol 10 (47) ◽

pp. 28464-28477

Author(s):

Paula Tarttelin Hernández ◽

Stephen M. V. Hailes ◽

Ivan P. Parkin

Keyword(s):

Metal Oxide ◽

Gas Sensors ◽

Sensor Array ◽

Sensor Arrays ◽

Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

Semiconductor Sensor ◽

Gas Sensor Array ◽

Semiconductor Gas Sensors ◽

Metal Oxide Semiconductor Sensor

Metal oxide semiconductor gas sensors based on SnO2 and Cr2O3 were modified with zeolites H-ZSM-5, Na-A and H–Y to create a gas sensor array to detect cocaine by-product, methyl benzoate. SVMs were later used with a 4 sensor array to classify 9 gases of interest.

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Significant Enhancement of Hydrogen-Sensing Properties of ZnO Nanofibers through NiO Loading

Nanomaterials ◽

10.3390/nano8110902 ◽

2018 ◽

Vol 8 (11) ◽

pp. 902 ◽

Cited By ~ 18

Author(s):

Jae-Hyoung Lee ◽

Jin-Young Kim ◽

Ali Mirzaei ◽

Hyoun Kim ◽

Sang Kim

Keyword(s):

Metal Oxide ◽

Gas Sensors ◽

High Performance ◽

Gas Sensing ◽

Hydrogen Gas ◽

Electrospinning Technique ◽

Calcination Process ◽

Hydrogen Sensing ◽

Zno Nanofibers ◽

P Type

Metal oxide p-n heterojunction nanofibers (NFs) are among the most promising approaches to enhancing the efficiency of gas sensors. In this paper, we report the preparation of a series of p-NiO-loaded n-ZnO NFs, namely (1−x)ZnO-xNiO (x = 0.03, 0.05, 0.7, 0.1, and 0.15 wt%), for hydrogen gas sensing experiments. Samples were prepared through the electrospinning technique followed by a calcination process. The sensing experiments showed that the sample with 0.05 wt% NiO loading resulted in the highest sensing performance at an optimal sensing temperature of 200 °C. The sensing mechanism is discussed in detail and contributions of the p-n heterojunctions, metallization of ZnO and catalytic effect of NiO on the sensing enhancements of an optimized gas sensor are analyzed. This study demonstrates the possibility of fabricating high-performance H2 sensors through the optimization of p-type metal oxide loading on the surfaces of n-type metal oxides.

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Significant Enhancement of Hydrogen-Sensing Properties of ZnO Nanofibers through NiO Loading

10.20944/preprints201808.0354.v1 ◽

2018 ◽

Author(s):

Jae-Hyoung Lee ◽

Jin-Young Kim ◽

Ali Mirzaei ◽

Hyoun Woo Kim ◽

Sang Sub Kim

Keyword(s):

Metal Oxide ◽

Gas Sensors ◽

High Performance ◽

Gas Sensing ◽

Hydrogen Gas ◽

Electrospinning Technique ◽

Calcination Process ◽

Hydrogen Sensing ◽

Zno Nanofibers ◽

P Type

Metal oxide p-n heterojunction nanofibers (NFs) are among the most promising approaches to enhancing the efficiency of gas sensors. In this paper, we report the preparation of a series of p-NiO-loaded n-ZnO NFs, namely (1 − x) ZnO-xNiO (x = 0.03, 0.05, and 0.1 wt%), for hydrogen gas sensing experiments. Samples were prepared through the electrospinning technique followed by a calcination process. The sensing experiments showed that the sample with 0.05 wt% NiO loading resulted in the highest sensing performance at an optimal sensing temperature of 200 °C. The sensing mechanism is discussed in detail and contributions of the p-n heterojunctions, metallization of ZnO and catalytic effect of NiO on the sensing enhancements of an optimized gas sensor are analyzed. This study demonstrates the possibility of fabricating high-performance H2 sensors through the optimization of p-type metal oxide loading on the surfaces of n-type metal oxides.

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Metal-oxide based ammonia gas sensors: A review

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681210999200718005402 ◽

2020 ◽

Vol 10 ◽

Author(s):

Priya Gupta ◽

Savita Maurya ◽

Narendra Kumar Pandey ◽

Vernica Verma

Keyword(s):

Metal Oxide ◽

Metal Oxides ◽

Gas Sensor ◽

Gas Sensors ◽

Review Paper ◽

Gas Sensing ◽

Gas Sensitivity ◽

Ammonia Gas ◽

Ammonia Sensing ◽

Ammonia Gas Sensors

: This review paper encompasses a study of metal-oxide and their composite based gas sensors used for the detection of ammonia (NH3) gas. Metal-oxide has come into view as an encouraging choice in the gas sensor industry. This review paper focuses on the ammonia sensing principle of the metal oxides. It also includes various approaches adopted for increasing the gas sensitivity of metal-oxide sensors. Increasing the sensitivity of the ammonia gas sensor includes size effects and doping by metal or other metal oxides which will change the microstructure and morphology of the metal oxides. Different parameters that affect the performances like sensitivity, stability, and selectivity of gas sensors are discussed in this paper. Performances of the most operated metal oxides with strengths and limitations in ammonia gas sensing application are reviewed. The challenges for the development of high sensitive and selective ammonia gas sensor are also discussed.

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Advanced development of metal oxide nanomaterials for H2 gas sensing applications

Materials Advances ◽

10.1039/d0ma00880j ◽

2021 ◽

Author(s):

Yushu Shi ◽

Huiyan Xu ◽

Tongyao Liu ◽

Shah Zeb ◽

Yong Nie ◽

...

Keyword(s):

Metal Oxide ◽

Gas Sensors ◽

Gas Sensing ◽

The Past ◽

Sensing Applications ◽

The Future ◽

Metal Oxide Nanomaterials ◽

Nanomaterials Synthesis ◽

Advanced Development

The scheme of the structure of this review includes an introduction from the metal oxide nanomaterials’ synthesis to application in H2 gas sensors—a vision from the past to the future.

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Electrophoretic deposition of Au NPs on CNT networks for sensitive NO2 detection

Journal of Sensors and Sensor Systems ◽

10.5194/jsss-3-245-2014 ◽

2014 ◽

Vol 3 (2) ◽

pp. 245-252 ◽

Cited By ~ 3

Author(s):

E. Dilonardo ◽

M. Penza ◽

M. Alvisi ◽

C. Di Franco ◽

D. Suriano ◽

...

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Gas Sensing ◽

Spectroscopic Characterization ◽

Core Diameter ◽

Au Nps ◽

Transmission Electron ◽

P Type ◽

Reducing Gases ◽

The Impact

Abstract. In the present study, Au-surfactant core-shell colloidal nanoparticles (NPs) with controlled dimension and composition were synthesized by sacrificial anode electrolysis. Transmission electron microscopy (TEM) revealed that Au NPs core diameter is between 8 and 12 nm, as a function of the electrosynthesis conditions. Moreover, surface spectroscopic characterization by X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of nanosized gold phase. Controlled amounts of Au NPs were then deposited electrophoretically on carbon nanotube (CNT) networked films. The resulting hybrid materials were morphologically and chemically characterized using TEM, SEM (scanning electron microscopy) and XPS analyses, which revealed the presence of nanoscale gold, and its successful deposition on CNTs. Au NP/CNT networked films were tested as active layers in a two-pole resistive NO2 sensor for sub-ppm detection in the temperature range of 100–200 °C. Au NP/CNT exhibited a p-type response with a decrease in the electrical resistance upon exposure to oxidizing NO2 gas and an increase in resistance upon exposure to reducing gases (e.g. NH3). It was also demonstrated that the sensitivity of the Au NP/CNT-based sensors depends on Au loading; therefore, the impact of the Au loading on gas sensing performance was investigated as a function of the working temperature, gas concentration and interfering gases.

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Curating Metal-Organic Frameworks to Compose Robust Gas Sensor Arrays in Dilute Conditions

10.26434/chemrxiv.8179244.v2 ◽

2019 ◽

Author(s):

Arni Sturluson ◽

Rachel Sousa ◽

Yujing Zhang ◽

Melanie T. Huynh ◽

Caleb Laird ◽

...

Keyword(s):

Sensor Array ◽

Gas Sensing ◽

Metal Organic Frameworks ◽

Sensor Arrays ◽

Gas Composition ◽

Composition Space ◽

The Matrix ◽

Metal Organic ◽

Analyte Detection ◽

Value Decomposition

Metal-organic frameworks (MOFs)-- tunable, nano-porous materials-- are alluring recognition elements for gas sensing. Mimicking human olfaction, an array of cross-sensitive, MOF-based sensors could enable analyte detection in complex, variable gas mixtures containing confounding gas species. Herein, we address the question: given a set of MOF candidates and their adsorption properties, how do we select the optimal subset to compose a sensor array that accurately and robustly predicts the gas composition via monitoring the adsorbed mass in each MOF? We first mathematically formulate the MOF-based sensor array problem under dilute conditions. Instructively, the sensor array can be viewed as a linear map from gas composition space to sensor array response space defined by the matrix H of Henry coefficients of the gases in the MOFs. Characterizing this mapping, the singular value decomposition of H is a useful tool for evaluating MOF subsets for sensor arrays, as it determines the sensitivity of the predicted gas composition to measurement error, quantifies the magnitude of the response to changes in composition, and recovers which direction in gas composition space elicits the largest/smallest response. To illustrate, on the basis of experimental adsorption data, we curate MOFs for a sensor array with the objective of determining the concentration of CO2 and SO2 in the gas phase.

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