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

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.

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

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 902 ◽  
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.

scholarly journals Enhanced Hydrogen Detection in ppb-Level by Electrospun SnO2-Loaded ZnO Nanofibers

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 726 ◽  
Author(s):  
Jae-Hyoung Lee ◽  
Jin-Young Kim ◽  
Jae-Hun Kim ◽  
Sang Kim
Keyword(s):  
Gas Sensor ◽  
High Performance ◽  
Hydrogen Gas ◽  
Hydrogen Sensors ◽  
Excellent Performance ◽  
Electrospinning Technique ◽  
Hydrogen Sensing ◽  
Working Temperature ◽  
Highly Sensitive ◽  
Zno Nanofibers

High-performance hydrogen sensors are important in many industries to effectively address safety concerns related to the production, delivering, storage and use of H2 gas. Herein, we present a highly sensitive hydrogen gas sensor based on SnO2-loaded ZnO nanofibers (NFs). The xSnO2-loaded (x = 0.05, 0.1 and 0.15) ZnO NFs were fabricated using an electrospinning technique followed by calcination at high temperature. Microscopic analyses demonstrated the formation of NFs with expected morphology and chemical composition. Hydrogen sensing studies were performed at various temperatures and the optimal working temperature was selected as 300 °C. The optimal gas sensor (0.1 SnO2 loaded ZnO NFs) not only showed a high response to 50 ppb hydrogen gas, but also showed an excellent selectivity to hydrogen gas. The excellent performance of the gas sensor to hydrogen gas was mainly related to the formation of SnO2-ZnO heterojunctions and the metallization effect of ZnO.

High performance hydrogen gas sensors based on PdO-decorated p-type CoV2O6 nanoparticles

2020 ◽  
Vol 324 ◽  
pp. 128744
Author(s):  
M. Moschogiannaki ◽  
L. Zouridi ◽  
J. Sukunta ◽  
S. Phanichphant ◽  
E. Gagaoudakis ◽  
...  
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Hydrogen Gas ◽  
Hydrogen Gas Sensors ◽  
P Type

scholarly journals ppb-Level Selective Hydrogen Gas Detection of Pd-Functionalized In2O3-Loaded ZnO Nanofiber Gas Sensors

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4276 ◽  
Author(s):  
Jae-Hyoung Lee ◽  
Jae-Hun Kim ◽  
Jin-Young Kim ◽  
Ali Mirzaei ◽  
Hyoun Woo Kim ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Strong Response ◽  
Pd Nanoparticle ◽  
Highly Sensitive ◽  
Hydrogen Gas Sensors ◽  
Zno Nanofibers ◽  
Gas Response ◽  
Hydrogen Gas Detection

Pd nanoparticle-functionalized, xIn2O3 (x = 0.05, 0.1, and 0.15)-loaded ZnO nanofibers were synthesized by an electrospinning and ultraviolet (UV) irradiation method and assessed for their hydrogen gas sensing properties. Morphological and chemical analyses revealed the desired morphology and chemical composition of the synthesized nanofibers. The optimal gas sensor namely Pd-functionalized, 0.1In2O3-loaded ZnO nanofibers showed a very strong response to 172–50 ppb hydrogen gas at 350 °C, which is regarded as the optimal sensing temperature. Furthermore, the gas sensors showed excellent selectivity to hydrogen gas due to the much lower response to CO and NO2 gases. The enhanced gas response was attributed to the excellent catalytic activity of Pd to hydrogen gas, and the formation of Pd/ZnO and In2O3/ZnO heterojunctions, ZnO–ZnO homojunction, as well as the formation of PdHx. Overall, highly sensitive and selective hydrogen gas sensors can be produced based on a simple methodology using a synergistic effect from Pd functionalization and In2O3 loading in ZnO nanofibers.

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

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2710
Author(s):  
Jianghua Luo ◽  
Yishan Jiang ◽  
Feng Xiao ◽  
Xin Zhao ◽  
Zheng Xie
Keyword(s):  
Electron Microscopy ◽  
Metal Oxide ◽  
Gas Sensors ◽  
Sensor Array ◽  
Gas Sensing ◽  
Sensor Arrays ◽  
Low Concentration ◽  
Highly Sensitive ◽  
Doped Zno ◽  
P Type

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.

scholarly journals Superior Hydrogen Sensing Property of Porous NiO/SnO2 Nanofibers Synthesized via Carbonization

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1250 ◽  
Author(s):  
Hongcheng Liu ◽  
Feipeng Wang ◽  
Kelin Hu ◽  
Bin Zhang ◽  
Li He ◽  
...  
Keyword(s):  
High Performance ◽  
Surface Reaction ◽  
Gas Sensing ◽  
Hydrogen Gas ◽  
Pure Sno2 ◽  
Hydrogen Sensing ◽  
Adsorption Sites ◽  
Electrospinning Method ◽  
Sensor Devices ◽  
Different Grain Size

In this paper, the porous NiO/SnO2 nanofibers were synthesized via the electrospinning method along with the carbonization process. The characterization results show that the pristine SnO2-based nanofibers can form porous structure with different grain size by carbonization. The hydrogen gas-sensing investigations indicate that the NiO/SnO2 sensor exhibits more prominent sensing properties than those of pure SnO2 sensor devices. Such enhanced performance is mainly attributed to the porous nanostructure, which can provide large active adsorption sites for surface reaction. Moreover, the existence of p-n heterojunctions between NiO and SnO2 also plays a key role in enhancing gas-sensing performances. Finally, the H2 sensing mechanism based on the NiO/SnO2 nanocomposite was proposed for developing high-performance gas sensor devices.

Metal-oxide based ammonia gas sensors: A review

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.

P-type Co3O4 nanoarrays decorated on the surface of n-type flower-like WO3 nanosheets for high-performance gas sensing

2019 ◽  
Vol 288 ◽  
pp. 104-112 ◽  
Author(s):  
Yanghai Gui ◽  
Lele Yang ◽  
Kuan Tian ◽  
Hongzhong Zhang ◽  
Shaoming Fang
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
P Type ◽  
Co3o4 Nanoarrays

scholarly journals Optimization of a Low-Power Chemoresistive Gas Sensor: Predictive Thermal Modelling and Mechanical Failure Analysis

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 783 ◽  
Author(s):  
Andrea Gaiardo ◽  
David Novel ◽  
Elia Scattolo ◽  
Michele Crivellari ◽  
Antonino Picciotto ◽  
...  
Keyword(s):  
Low Power ◽  
Failure Analysis ◽  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Mechanical Failure ◽  
Sensing Applications ◽  
Theoretical Approaches ◽  
Sensing Material ◽  
Silicon Bulk

The substrate plays a key role in chemoresistive gas sensors. It acts as mechanical support for the sensing material, hosts the heating element and, also, aids the sensing material in signal transduction. In recent years, a significant improvement in the substrate production process has been achieved, thanks to the advances in micro- and nanofabrication for micro-electro-mechanical system (MEMS) technologies. In addition, the use of innovative materials and smaller low-power consumption silicon microheaters led to the development of high-performance gas sensors. Various heater layouts were investigated to optimize the temperature distribution on the membrane, and a suspended membrane configuration was exploited to avoid heat loss by conduction through the silicon bulk. However, there is a lack of comprehensive studies focused on predictive models for the optimization of the thermal and mechanical properties of a microheater. In this work, three microheater layouts in three membrane sizes were developed using the microfabrication process. The performance of these devices was evaluated to predict their thermal and mechanical behaviors by using both experimental and theoretical approaches. Finally, a statistical method was employed to cross-correlate the thermal predictive model and the mechanical failure analysis, aiming at microheater design optimization for gas-sensing applications.

scholarly journals Advanced development of metal oxide nanomaterials for H2 gas sensing applications

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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