The Experts below are selected from a list of 38343 Experts worldwide ranked by ideXlab platform
Abdulqader D. Faisal - One of the best experts on this subject based on the ideXlab platform.
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Ethanol Gas Sensor Fabrication Based on ZnO Flower Like Nanorods
Engineering and Technology Journal, 2020Co-Authors: Abdulqader D. Faisal, Mofeed Abdul Latif Jaleel, Fahad Zaher KamalAbstract:Zinc oxide flower-like nanorods (ZnO NRs) was successfully synthesized via the hydrothermal method. The growth process was conducted with seed layer concentrations of 20mM. The as-synthesized nanostructures were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), and ultraviolet-visible (UV-VIS) spectrophotometer. The analysis results revealed a pure Wurtzite ZnO hexagonal nanostructures with preferred orientation (002) along the c-direction. The calculated band gap of average crystallite size is 3.2eV and 25 nm respectively. New designed, constructed and successfully calibrated for ethanol gas sensing was found. The ethanol gas Sensor was fabricated at room temperature based on the ZnO NRs film. The synthesized materials proved to be a good candidate for the ethanol gas Sensor. The optimum results of the gas Sensor measurements of the synthesized gas Sensor are as follows, the sensitivity, response time, and recovery time at 25 °C are 60%, 80 Seconds and 80 seconds respectively, and at 200 °C are 70%, 60 seconds and 50 seconds respectively.
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Synthesis of gold-coated branched ZnO nanorods for gas Sensor Fabrication
Journal of Nanoparticle Research, 2020Co-Authors: Ameen Thamer, Abdulqader D. Faisal, Ali L. Abed, Wafaa K. KhalefAbstract:In this work, atypical zinc oxide nanorods (ZnO NRs) on quartz substrates were successfully synthesized using simple, low-cost, and environmentally friendly hydrothermal method. The ZnO NRs were grown on a pre-seeded seed layer of ZnO nanocrystals using the spin coating process. Gold nanoparticles (Au NPs) were sputtered on the ZnO NRs film. The structure and morphology of the produced nanostructures were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analysis revealed that the ZnO NRs were single crystalline with hexagonal wurtzite structure grown with preferred orientation of (002). The SEM morphology shows a semi-hierarchical ZnO NRs with an estimated diameter of 200–400 nm and length of 4–5 μm. The optical properties of the ZnO NRs film were investigated using UV-visible spectrophotometers. The obtained bandgap of ZnO film was 3.0 eV. Electrical and thermal properties were also measured. The resistance changes versus temperature variation of ZnO NRs were given a semiconductor behavior. The gas Sensor was fabricated based on bare ZnO NRs and Au NPs/ZnO NRs hybrid. The second nanostructure exhibited an enhanced Sensor sensitivity toward ethanol gas at an optimized working temperature of 325 °C.
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Synthesis of ZnO comb-like nanostructures for high sensitivity $$\hbox {H}_{2}$$ H
Bulletin of Materials Science, 2017Co-Authors: Abdulqader D. FaisalAbstract:Zinc oxide (ZnO) comb-like nanostructures were successfully synthesized on the silicon substrate without a catalyst via chemical vapour deposition. The morphology and crystal structure of the product were characterized by scanning electron microscope and X-ray diffractometer. In this research, a simple gas Sensor was fabricated based on the principle of change in resistivity due to oxygen vacancies, which makes its surface chemically and electrically active. The fabricated ZnO nanostructures proved to be quite sensitive to low concentration of $$\hbox {H}_{2}\hbox {S}$$ H 2 S gas at room temperature. The sensitivity and response time were measured as a function of gas concentrations. Small response time (48–22 s) and long recovery time (540 s) were found at $$\hbox {H}_{2}\hbox {S}$$ H 2 S gas concentrations of 0.1–4 ppm, respectively. ZnO comb-like structures are considered as the most suitable materials for gas Sensor Fabrication due to their high sensing properties. These nanostructures growth and $$\hbox {H}_{2}\hbox {S}$$ H 2 S gas sensing mechanism were also discussed.
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Synthesis of ZnO comb-like nanostructures for high sensitivity $$\hbox {H}_{2}$$S gas Sensor Fabrication at room temperature
Bulletin of Materials Science, 2017Co-Authors: Abdulqader D. FaisalAbstract:Zinc oxide (ZnO) comb-like nanostructures were successfully synthesized on the silicon substrate without a catalyst via chemical vapour deposition. The morphology and crystal structure of the product were characterized by scanning electron microscope and X-ray diffractometer. In this research, a simple gas Sensor was fabricated based on the principle of change in resistivity due to oxygen vacancies, which makes its surface chemically and electrically active. The fabricated ZnO nanostructures proved to be quite sensitive to low concentration of \(\hbox {H}_{2}\hbox {S}\) gas at room temperature. The sensitivity and response time were measured as a function of gas concentrations. Small response time (48–22 s) and long recovery time (540 s) were found at \(\hbox {H}_{2}\hbox {S}\) gas concentrations of 0.1–4 ppm, respectively. ZnO comb-like structures are considered as the most suitable materials for gas Sensor Fabrication due to their high sensing properties. These nanostructures growth and \(\hbox {H}_{2}\hbox {S}\) gas sensing mechanism were also discussed.
John P. Hart - One of the best experts on this subject based on the ideXlab platform.
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Screen-printed electrochemical Sensors for monitoring metal pollutants
TrAC Trends in Analytical Chemistry, 2003Co-Authors: Kevin C. Honeychurch, John P. HartAbstract:This review describes current developments in the design and Fabrication of disposable screen-printed Sensors for the electrochemical determination of trace metals in biological, environmental and industrial samples. Specific emphasis is placed on Sensor-Fabrication methods, operating details and performance characteristics for selected applications.
Kevin C. Honeychurch - One of the best experts on this subject based on the ideXlab platform.
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Screen-printed electrochemical Sensors for monitoring metal pollutants
TrAC Trends in Analytical Chemistry, 2003Co-Authors: Kevin C. Honeychurch, John P. HartAbstract:This review describes current developments in the design and Fabrication of disposable screen-printed Sensors for the electrochemical determination of trace metals in biological, environmental and industrial samples. Specific emphasis is placed on Sensor-Fabrication methods, operating details and performance characteristics for selected applications.
Weili Wei - One of the best experts on this subject based on the ideXlab platform.
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Recent advances in graphene quantum dots for sensing
Materials Today, 2013Co-Authors: Hanjun Sun, Weili WeiAbstract:Graphene quantum dots (GQDs) are a kind of 0D material with characteristics derived from both graphene and carbon dots (CDs). Combining the structure of graphene with the quantum confinement and edge effects of CDs, GQDs possess unique properties. In this review, we focus on the application of GQDs in electronic, photoluminescence, electrochemical and electrochemiluminescence Sensor Fabrication, and address the advantages of GQDs on physical analysis, chemical analysis and bioanalysis. We have summarized different techniques and given future perspectives for developing smart sensing based on GQDs.
Jai P. Mittal - One of the best experts on this subject based on the ideXlab platform.
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Macroporous silicon based capacitive affinity Sensor—Fabrication and electrochemical studies
Sensors and Actuators B: Chemical, 2004Co-Authors: Chirayath A. Betty, R. Lal, Dinesh K. Sharma, J. V. Yakhmi, Jai P. MittalAbstract:We report the Fabrication and characterization of capacitive immunoSensors based on electrolyte-insulator-porous silicon (EIS) structures. The Sensor structure, gold\silicon\porous silicon\SiO2\aminosilane\glutaraldehyde\antibody\phosphate-buffered-saline (PBS)\platinum, is fabricated with a low thermal budget process and is found to be five times more sensitive than an immunoSensor on polished silicon with identical die area. Macroporous silicon was prepared by electrochemical etching of polished (100) oriented p-type silicon wafers and characterized using SEM, optical microscopy, cyclic voltammetry and impedance spectroscopy. Columnar macroporous structures of different column densities and column sizes were used as the Sensor substrates. The capacitive immunoSensors were fabricated by anodic oxidation of these porous silicon substrates to form oxide followed by covalent immobilization of antibody (mouse IgG). Antibody-analyte (goat anti-mouse IgG) interactions were monitored via fluorescence microscopy and by change in the measured capacitance. Sensor response was dependent on both the porous silicon column structure and oxide quality. (C) 200
