Fabrication and Morphological Control of a Palladium Film with a Three-Dimensional Nano-Network Structure as a Hydrogen Gas Sensing Material using Organic Acid Chelation

MRS Advances ◽  
2019 ◽  
Vol 4 (5-6) ◽  
pp. 319-324
Author(s):  
Takuji Ube ◽  
Akizumi Kawamoto ◽  
Tomoya Nishi ◽  
Takashi Ishiguro
Keyword(s):  
Organic Acid ◽  
Network Structure ◽  
Gas Sensing ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Strong Acid ◽  
Alloy Film ◽  
Hydrogen Gas ◽  
Sensing Material ◽  
Sensitivity And Selectivity

ABSTRACTNano-porous palladium (Pd) thin films could potentially be applied to hydrogen gas sensing materials with high sensitivity and selectivity. In our previous study, a nano-porous Pd film was fabricated with a three-dimensional network structure from an AlPd mother alloy film by a dealloying method using the chelating ability of an organic acid. This process was simple and environmentally friendly because it only required organic acid in a ppm concentration, and did not exhaust a strong acid waste solution, including heavy metal ions. This method was modified to improve the Pd purity of the dealloyed specimen, reaction rate, and morphology control. In this study, the existence of a composition undulation pattern was shown in the AlPd mother alloy film, and its effects on the morphology of the dealloyed specimen were evaluated. Furthermore, this pattern could be controlled by N2 gas addition to the Ar sputtering gas during the preparation of the AlPd mother alloy film.

scholarly journals Hydrogen Gas Sensing Using Palladium-Graphene Nanocomposite Material Based on Surface Acoustic Wave

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Nguyen Hai Ha ◽  
Nguyen Hoang Nam ◽  
Dang Duc Dung ◽  
Nguyen Huy Phuong ◽  
Phan Duy Thach ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Gas Sensing ◽  
Specific Interaction ◽  
High Sensitivity ◽  
Fast Response ◽  
Hydrogen Gas ◽  
Chemical Route ◽  
Response Recovery ◽  
Sensing Material

We report the fabrication and characterization of surface acoustic wave (SAW) hydrogen sensors using palladium-graphene (Pd-Gr) nanocomposite as sensing material. The Pd-Gr nanocomposite as sensing layer was deposited onto SAW delay line sensor-based interdigitated electrodes (IDTs)/aluminum nitride (AlN)/silicon (Si) structure. The Pd-Gr nanocomposite was synthesized by a chemical route and deposited onto SAW sensors by air-brush spraying. The SAW H2 sensor using Pd-Gr nanocomposite as a sensing layer shows a frequency shift of 25 kHz in 0.5% H2 concentration at room temperature with good repeatability and stability. Moreover, the sensor showed good linearity and fast response/recovery within ten seconds with various H2 concentrations from 0.25 to 1%. The specific interaction between graphene and SAW transfer inside AlN/Si structures yields a high sensitivity and fast response/recovery of SAW H2 sensor based on Pd-Gr/AlN/Si structure.

Schottky diodes based on 2D materials for environmental gas monitoring: a review on emerging trends, recent developments and future perspectives

2021 ◽  
Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout
Keyword(s):  
Gas Sensing ◽  
2D Materials ◽  
Schottky Diodes ◽  
High Sensitivity ◽  
Future Perspectives ◽  
Working Temperature ◽  
Emerging Trends ◽  
Gas Sensing Properties ◽  
Recent Developments ◽  
Sensitivity And Selectivity

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.

Efficient chemosensors for toxic pollutants based on photoluminescent Zn(II) and Cd(II) metal-organic networks

2021 ◽  
Author(s):  
Luis David Rosales-Vazquez ◽  
Alejandro Dorazco-González ◽  
Victor Sanchez-Mendieta
Keyword(s):  
Optical Sensors ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Environmental Research ◽  
Toxic Pollutants ◽  
Sensitivity And Selectivity ◽  
Metal Organic ◽  
Analytical Tools ◽  
Organic Networks

Optical sensors with high sensitivity and selectivity, as important analytical tools for chemical and environmental research, can be accomplished by straightforward synthesis of luminescent one-, two- and three-dimensional Zn(II) and...

scholarly journals Fabrication of Transition-metal (Zn, Mn, Cu)-based MOFs as Efficient Sensor Materials for Detection of H2 Gas by Clad Modified Fiber Optic Gas Sensor Technique

2021 ◽  
Author(s):  
M Nagoor Meeran ◽  
S.P. Saravanan ◽  
H.H Hegazy
Keyword(s):  
Transition Metal ◽  
Fiber Optic ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Long Term Stability ◽  
Sensing Material ◽  
Sensor Technique ◽  
Recent Developments ◽  
Metal Organic ◽  
Elevated Surface

Abstract Recent research demonstrate that promising gas sensing materials are called metal-organic structures (MOFs) and their products due to their tunable form, elevated surface area, and extremely porous structure and physisorption towards gases with relatively low temperature.In this report, recent developments in transition-metal (Zn, Mn, Cu)-based MOFs and their derivatives are synthesized as sensing materials. The sensors samples were analyzed by XRD, SEM, TEM, BET and XPS in order to know the textural, structural and electronic state of the samples. Fiber optic clad modified sensors were fabricated and tested gas sensing properties towards H2 gas with various concentrations (0-1000 ppm). Among the three sensing material, Zn doped MOFs sensor showed outstanding selectivity with high sensitivity (115 counts/kpa) towards H2 gas. Moreover, it has shown high response (20 s) and recovery time (27 s) as well as long term stability. The designed sensors may be required to apply to the production of an outstanding sensor for H2 for commercial uses.

Easy-to-Fabricate K2Pd(SO3)2-Dyed Polyester Fabric with Highly Selective and Fast Response to Carbon Monoxide

2021 ◽  
Vol 21 (8) ◽  
pp. 4400-4405
Author(s):  
Junyeop Lee ◽  
Nam Gon Do ◽  
Dong Hyuk Jeong ◽  
Sae-Wan Kim ◽  
Maeum Han ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Color Change ◽  
High Sensitivity ◽  
Cost Effective ◽  
Fast Response ◽  
Polyester Fabric ◽  
High Porosity ◽  
Sensing Material ◽  
Sensitivity And Selectivity ◽  
And Performance

Carbon monoxide (CO) is an odorless, colorless, tasteless, extremely flammable, and highly toxic gas. It is produced when there is insufficient oxygen supply during the combustion of carbon to produce carbon dioxide (CO2). CO is produced from operating engines, stoves, or furnaces. CO poisoning occurs when CO accumulates in the bloodstream and can result in severe tissue damage or even death. Many types of CO sensors have been reported, including electrochemical, semiconductor metal-oxide, catalytic combustion, thermal conductivity, and infrared absorption-type for the detection of CO. However, despite their excellent selectivity and sensitivity, issues such as complexity, power consumption, and calibration limit their applications. In this study, a fabricbased colorimetric CO sensor is proposed to address these issues. Potassium disulfitopalladate (II) (K2Pd(SO3)2) is dyed on a polyester fabric as a sensing material for selective CO detection. The sensing characteristics and performance are investigated using optical instruments such as RGB sensor and spectrometer. The sensor shows immediate color change when exposed to CO at a concentration that is even lower than 20 ppm before 2 min. The fast response time of the sensor is attributed to its high porosity to react with CO. This easy-to-fabricate and cost-effective sensor can detect and prevent the leakage of CO simultaneously with high sensitivity and selectivity toward CO.

A metal-organic framework featuring highly sensitive fluorescence sensing for Al3+ ion

CrystEngComm ◽  
2021 ◽  
Author(s):  
Yang Qiao ◽  
Zeqi Li ◽  
Mei-Hui Yu ◽  
Ze Chang ◽  
Xian-He Bu
Keyword(s):  
Metal Ions ◽  
Human Health ◽  
Metal Organic Framework ◽  
High Sensitivity ◽  
Fluorescence Sensing ◽  
Sensing Material ◽  
Highly Sensitive ◽  
Sensitivity And Selectivity ◽  
Metal Organic ◽  
Organic Framework

High sensitivity and selectivity for detection of metal ions are very important to protect human health. Fluorescent metal-organic framework (MOF) as a new sensing material has attracted more and more...

scholarly journals Highly Sensitive, Selective, Flexible and Scalable Room-Temperature NO2 Gas Sensor Based on Hollow SnO2/ZnO Nanofibers

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6475
Author(s):  
Jiahui Guo ◽  
Weiwei Li ◽  
Xuanliang Zhao ◽  
Haowen Hu ◽  
Min Wang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Positive Impact ◽  
High Sensitivity ◽  
Detection Sensitivity ◽  
Pure Sno2 ◽  
Flexible Devices ◽  
Low Concentrations ◽  
Highly Sensitive ◽  
Sensitivity And Selectivity

Semiconducting metal oxides can detect low concentrations of NO2 and other toxic gases, which have been widely investigated in the field of gas sensors. However, most studies on the gas sensing properties of these materials are carried out at high temperatures. In this work, Hollow SnO2 nanofibers were successfully synthesized by electrospinning and calcination, followed by surface modification using ZnO to improve the sensitivity of the SnO2 nanofibers sensor to NO2 gas. The gas sensing behavior of SnO2/ZnO sensors was then investigated at room temperature (~20 °C). The results showed that SnO2/ZnO nanocomposites exhibited high sensitivity and selectivity to 0.5 ppm of NO2 gas with a response value of 336%, which was much higher than that of pure SnO2 (13%). In addition to the increase in the specific surface area of SnO2/ZnO-3 compared with pure SnO2, it also had a positive impact on the detection sensitivity. This increase was attributed to the heterojunction effect and the selective NO2 physisorption sensing mechanism of SnO2/ZnO nanocomposites. In addition, patterned electrodes of silver paste were printed on different flexible substrates, such as paper, polyethylene terephthalate and polydimethylsiloxane using a facile screen-printing process. Silver electrodes were integrated with SnO2/ZnO into a flexible wearable sensor array, which could detect 0.1 ppm NO2 gas after 10,000 bending cycles. The findings of this study therefore open a general approach for the fabrication of flexible devices for gas detection applications.

Structure and Characteristics of Electrospun ZnO Nanofibers for Gas Sensing

2020 ◽  
Vol 16 (2) ◽  
pp. 187-195
Author(s):  
Tang-Yu Lai ◽  
Te-Hua Fang ◽  
Yu-Jen Hsiao ◽  
En-Yu Kuo
Keyword(s):  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Oxide Semiconductor ◽  
Woven Fabric ◽  
Membrane Thickness ◽  
One Dimensional ◽  
Sensing Mechanism ◽  
Sensing Material

Background:: A sensing material of zinc oxide (ZnO) was investigated for its use in the electrospun nanofibers for gas sensing. The metal oxide semiconductor gas sensor response is caused by the oxygen that undergoes a chemical reaction on the surface of an oxide, resulting in a change in the measured resistance. Objective:: One-dimensional nanofibers gas sensor have high sensitivity and diverse selectivity. Methods:: One-dimensional nanofiber by an electrospinning method was collected and a sensing membrane was formed. In addition, the gas sensing mechanism was discussed and verified by X-ray photoelectron spectroscopy (XPS). Results:: The ZnO nanofiber membrane had an optimum crystalline phase with a lattice spacing of 0.245 nm and a non-woven fabric structure at a calcination temperature of 500°C, whereas the nanofiber diameter and membrane thickness were about 100 nm and 8 μm, respectively. At an operating temperature of 200°C, the sensing material exhibited good recovery and reproducibility in response to Carbon monoxide (CO), and the concentration was also highly discernible. In addition, the reduction in the peak of OIII at 531.5 to 532.5 eV according to the analysis of XPS was consistent with the description of the sensing mechanism. Conclusion:: The gas sensor of ZnO nanofiber membranes has high sensitivity and diverse selectivity, which can be widely applied in potential applications in various sensors and devices.

scholarly journals An Effective Optical Dual Gas Sensor for Simultaneous Detection of Oxygen and Ammonia

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5124 ◽  
Author(s):  
Sajal Biring ◽  
Annada Sankar Sadhu ◽  
Moumita Deb
Keyword(s):  
Gas Sensor ◽  
Fluorescent Dyes ◽  
Low Cost ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Eosin Y ◽  
Practical Applications ◽  
Sensing Material ◽  
Dual Sensor ◽  
Sensitivity And Selectivity

The development of a simple, low-cost sensor for the effective sensing of multiple gases in industrial or residential zones has been in high demand in recent days. In this article, we have proposed an optical sensor for the dual sensing of oxygen (O2) and ammonia (NH3) gases, which consists of oxygen and ammonia-sensitive fluorescent dyes coated individually on both sides of a glass substrate. An ethyl cellulose (EC) matrix doped with platinum (II) meso-tetrakis (pentafluorophenyl) porphyrin (PtTFPP) serves as the oxygen-sensing material, whereas the NH3-sensing material includes an eosin Y fluorescent indicator immobilized within a cellulose acetate (CA) matrix. Both the oxygen and ammonia-sensitive materials were excited by the same LED light source with a 405 nm peak wavelength, while the corresponding emissions were detected separately for the selective sensing of the gases under study. The dual gas sensor exhibits maximum sensitivities of around 60 and 20 for oxygen and ammonia gases, respectively. The high sensitivity and selectivity of the proposed optical dual sensor suggests the feasibility of the simultaneous sensing of oxygen and ammonia for practical applications.

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