scholarly journals Enhancing Formaldehyde Selectivity of SnO2 Gas Sensors with the ZSM-5 Modified Layers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3947
Author(s):  
Wei Wang ◽  
Qinyi Zhang ◽  
Ruonan Lv ◽  
Dong Wu ◽  
Shunping Zhang
Keyword(s):  
Gas Sensors ◽  
Indoor Air ◽  
High Performance ◽  
Screen Printing ◽  
Gas Sensing ◽  
Oxide Semiconductors ◽  
Screen Printing Method ◽  
Gas Sensing Properties ◽  
Zeolite Films ◽  
Insufficient Knowledge

High performance formaldehyde gas sensors are widely needed for indoor air quality monitoring. A modified layer of zeolite on the surface of metal oxide semiconductors results in selectivity improvement to formaldehyde as gas sensors. However, there is insufficient knowledge on how the thickness of the zeolite layer affects the gas sensing properties. In this paper, ZSM-5 zeolite films were coated on the surface of the SnO2 gas sensors by the screen printing method. The thickness of ZSM-5 zeolite films was controlled by adjusting the numbers of screen printing layers. The influence of ZSM-5 film thickness on the performance of ZSM-5/SnO2 gas sensors was studied. The results showed that the ZSM-5/SnO2 gas sensors with a thickness of 19.5 μm greatly improved the selectivity to formaldehyde, and reduced the response to ethanol, acetone and benzene at 350 °C. The mechanism of the selectivity improvement to formaldehyde of the sensors was discussed.

Hierarchically designed ZnO nanostructure based high performance gas sensors

RSC Advances ◽  
2014 ◽  
Vol 4 (90) ◽  
pp. 49521-49528 ◽  
Author(s):  
Mohammad R. Alenezi ◽  
T. H. Alzanki ◽  
A. M. Almeshal ◽  
A. S. Alshammari ◽  
M. J. Beliatis ◽  
...  
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
High Surface ◽  
Hierarchical Nanostructures ◽  
Sensing Properties ◽  
Zno Nanostructure ◽  
Gas Sensing Properties

Enhanced gas sensing properties of ZnO were achieved by designing hierarchical nanostructures with high surface-to-volume ratios and more exposed polar facets.

A review: electrical and gas sensing properties of polyaniline/ferrite nanocomposites

Sensor Review ◽  
2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Thejas Ramakrishnaiah ◽  
Prasanna Gunderi Dhananjaya ◽  
Chaturmukha Vakwadi Sainagesh ◽  
Sathish Reddy ◽  
Swaroop Kumaraswamy ◽  
...  
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Room Temperature ◽  
Gas Sensing ◽  
Cost Effective ◽  
Content Type ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Gas Sensing Properties

Purpose This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of high-performance electrical and gas sensing materials operating at room temperature. Design/methodology/approach PANI/ferrite nanocomposites exhibit good electrical properties with lower dielectric losses. There are numerous reports on PANI and ferrite nanomaterial-based gas sensors which have good sensing response, feasible to operate at room temperature, requires less power and cost-effective. Findings This paper provides an overview of electrical and gas sensing properties of PANI/ferrite nanocomposites having improved selectivity, long-term stability and other sensing performance of sensors at room temperature. Originality/value The main purpose of this review paper is to focus on PANI/ferrite nanocomposite-based gas sensors operating at room temperature.

scholarly journals Gas Sensors Based on Oxide Semiconductors with Porous Nanostructures

Proceedings ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 13
Author(s):  
Peng Sun
Keyword(s):  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Synergistic Effects ◽  
Response Speed ◽  
High Specific Surface Area ◽  
Oxide Semiconductor ◽  
Oxide Semiconductors ◽  
Sensing Properties ◽  
Porous Nanostructures

Gas sensor as a device composed of sensing material coupled with signal transducer, has been acknowledged as an analytical tool for detection and quantification of inflammable, explosive or toxic gases. The gas sensors based on nanostructured oxide semiconductor endowed with excellent sensing properties have exhibited great potential application in the fields of environmental monitoring, resource exploration, medical welfare, etc. It is well known that the sensing mechanism of sensor employing oxide semiconductors is mainly that the interactions between the surface adsorbed oxygen species and target gases lead to a change in the electrical conductivity. Therefore, the gas sensing properties of oxide semiconductors are closely related with their composition, crystalline size, and microstructure. In this regard, design and preparation of oxides with novel architectures will be increasingly important in the construction of high performance gas sensors. Due to high specific surface area, low density, and good surface permeability, porous nanostructures oxide semiconductor sensing materials have attracted growing interest in recent years. In our work, we successfully prepared various porous nanostructures oxides and their composites to the construction of high performances gas sensors with enhanced sensitivity, selectivity, as well as lowered detection limit. The subsequent gas sensing measurements explicitly revealed that these oxides and composites manifested superior sensing behaviors (like much higher sensitivity and faster response speed), which can be ascribed to the porous architectures and the synergistic effects.

Semiconductor Gas Sensors for Environmental Monitoring

2006 ◽  
Vol 45 ◽  
pp. 1818-1827 ◽  
Author(s):  
M.C. Carotta ◽  
E. Ferrari ◽  
A. Giberti ◽  
C. Malagù ◽  
Marco Nagliati ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Screen Printing ◽  
Gas Sensing ◽  
Surface Barrier ◽  
Barrier Potential ◽  
Semiconductor Oxides ◽  
Screen Printing Technique ◽  
Gas Sensing Properties ◽  
Printing Technique ◽  
Semiconductor Gas Sensors

The main semiconductor oxides for gas sensing have been examined, describing the synthesis processes and the morphological and structural properties. The powders have been deposited as thick films through screen-printing technique to achieve gas sensors. The sensing layers have been studied with regard to semiconductor behaviour, surface barrier potential heights and gas sensing properties. The interaction of humidity with semiconductor oxides has been considered with the aim to compensate, using an algorithm, its effect in gas detection. Finally, nitrogen oxides monitoring, contemporaneously performed in several sites of Italy, has been described.

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 Oxygen-Deficient Stannic Oxide/Graphene for Ultrahigh-Performance Supercapacitors and Gas Sensors

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 372
Author(s):  
Liyang Lin ◽  
Susu Chen ◽  
Tao Deng ◽  
Wen Zeng
Keyword(s):  
Energy Storage ◽  
Gas Sensors ◽  
High Performance ◽  
Gas Sensing ◽  
Synthesis Method ◽  
Rate Capability ◽  
Stannic Oxide ◽  
Energy Storage Devices ◽  
Graphene Nanocomposites ◽  
Storage Devices

The metal oxides/graphene nanocomposites have great application prospects in the fields of electrochemical energy storage and gas sensing detection. However, rational synthesis of such materials with good conductivity and electrochemical activity is the topical challenge for high-performance devices. Here, SnO2/graphene nanocomposite is taken as a typical example and develops a universal synthesis method that overcome these challenges and prepares the oxygen-deficient SnO2 hollow nanospheres/graphene (r-SnO2/GN) nanocomposite with excellent performance for supercapacitors and gas sensors. The electrode r-SnO2/GN exhibits specific capacitance of 947.4 F g−1 at a current density of 2 mA cm−2 and of 640.0 F g−1 even at 20 mA cm−2, showing remarkable rate capability. For gas-sensing application, the sensor r-SnO2/GN showed good sensitivity (~13.8 under 500 ppm) and short response/recovering time toward methane gas. These performance features make r-SnO2/GN nanocomposite a promising candidate for high-performance energy storage devices and gas sensors.

scholarly journals Advanced Strategies to Improve Performances of Molybdenum-Based Gas Sensors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Angga Hermawan ◽  
Ni Luh Wulan Septiani ◽  
Ardiansyah Taufik ◽  
Brian Yuliarto ◽  
Suyatman ◽  
...  
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
Low Cost ◽  
Molybdenum Oxides ◽  
Exhaled Breath ◽  
Sensor Applications ◽  
Theoretical Investigations ◽  
Gas Sensing Properties ◽  
Future Challenges ◽  
Made In

AbstractMolybdenum-based materials have been intensively investigated for high-performance gas sensor applications. Particularly, molybdenum oxides and dichalcogenides nanostructures have been widely examined due to their tunable structural and physicochemical properties that meet sensor requirements. These materials have good durability, are naturally abundant, low cost, and have facile preparation, allowing scalable fabrication to fulfill the growing demand of susceptible sensor devices. Significant advances have been made in recent decades to design and fabricate various molybdenum oxides- and dichalcogenides-based sensing materials, though it is still challenging to achieve high performances. Therefore, many experimental and theoretical investigations have been devoted to exploring suitable approaches which can significantly enhance their gas sensing properties. This review comprehensively examines recent advanced strategies to improve the nanostructured molybdenum-based material performance for detecting harmful pollutants, dangerous gases, or even exhaled breath monitoring. The summary and future challenges to advance their gas sensing performances will also be presented.

A Novel Tungsten Trioxide Based Gas Sensor for Indoor Formaldehyde Detection

2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Material ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Gas Response

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.

A Strategy to Improve O2 Gas Response of La-SnO2 Nanofibers Based Sensor through Temperature Modulation

2019 ◽  
Vol 944 ◽  
pp. 657-665
Author(s):  
Ya Xiong ◽  
Hui Li ◽  
Tian Chao Guo ◽  
Qing Zhong Xue
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Operation Mode ◽  
Temperature Modulation ◽  
Oxide Semiconductors ◽  
Oxygen Ions ◽  
Isothermal Test ◽  
Sensor Temperature ◽  
Heating Energy Consumption ◽  
Gas Response

Generally sensing mechanisms of gas sensors based on metal-oxide semiconductors greatly depend on temperature, suggesting temperature modulation can be applied as a vital method to effectively enhance the sensor response. In this paper, we reported a strategy of quick-cooling operating temperature mode in the course of gas sensing process to elevate the O2 gas response while maintaining low heating energy consumption. La-SnO2 nanofibers synthesized by electrospinning were chosen as gas sensing materials. The O2 gas responses by employing quick-cooling operation mode are significantly improved compared with those obtained by traditional isothermal test. The improved O2 response is contributed to a higher coverage of negatively charged oxygen ions as a result of quick cooling. Our research offers a facile route to detect gas at low temperature with high response. More importantly, the strategy demonstrated here could also be extended to other gas sensor as long as its gas response is related to the sensor temperature.

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