- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Hydrogen Sensor Based on Tunable Diode Laser Absorption Spectroscopy
摘要： A laser-based hydrogen (H2) sensor using wavelength modulation spectroscopy (WMS) was developed for the contactless measurement of molecular hydrogen. The sensor uses a distributed feedback (DFB) laser to target the H2 quadrupole absorption line at 2121.8 nm. The H2 absorption line exhibited weak collisional broadening and strong collisional narrowing effects. Both effects were investigated by comparing measurements of the absorption linewidth with detailed models using different line profiles including collisional narrowing effects. The collisional broadening and narrowing parameters were determined for pure hydrogen as well as for hydrogen in nitrogen and air. The performance of the sensor was evaluated and the sensor applicability for H2 measurement in a range of 0–10 %v of H2 was demonstrated. A precision of 0.02 %v was achieved with 1 m of absorption pathlength (0.02 %v·m) and 1 s of integration time. For the optimum averaging time of 20 s, precision of 0.005 %v·m was achieved. A good linear relationship between H2 concentration and sensor response was observed. A simple and robust transmitter–receiver configuration of the sensor allows in situ installation in harsh industrial environments.
关键词： laser spectroscopy,WMS,diode laser,TDLAS,absorption spectroscopy,hydrogen sensor,hydrogen,gas sensor
更新于2025-09-11 14:15:04
-
Probing the Electronic Properties of Monolayer MoS <sub/>2</sub> via Interaction with Molecular Hydrogen
摘要： This work presents a detailed experimental investigation of the interaction between molecular hydrogen (H2) and monolayer MoS2 field effect transistors (MoS2 FET), aiming for sensing application. The MoS2 FET exhibits a response to H2 that covers a broad range of concentration (0.1–90%) at a relatively low operating temperature range (300–473 K). Most important, H2 sensors based on MoS2 FETs show desirable properties such as full reversibility and absence of catalytic metal dopants (Pt or Pd). The experimental results indicate that the conductivity of MoS2 monotonically increases as a function of the H2 concentration due to a reversible charge transferring process. It is proposed that such process involves dissociative H2 adsorption driven by interaction with sulfur vacancies in the MoS2 surface (VS). This description is in agreement with related density functional theory studies about H2 adsorption on MoS2. Finally, measurements on partially defect-passivated MoS2 FETs using atomic layer deposited aluminum oxide consist of an experimental indication that the VS plays an important role in the H2 interaction with the MoS2. These findings provide insights for future applications in catalytic process between monolayer MoS2 and H2 and also introduce MoS2 FETs as promising H2 sensors.
关键词： hydrogen gas sensor,gas interaction,hydrogen detection,monolayer MoS2,field effect transistors
更新于2025-09-10 09:29:36
-
Hydrogen gas sensing properties of WO3 sputter-deposited thin films enhanced by on-top deposited?CuO nanoclusters
摘要： Magnetron-based gas aggregation cluster source (GAS) was used to prepare high-purity CuO (cupric oxide) nanoclusters on top of sputter-deposited thin film of tungsten trioxide (WO3). The material was assembled as a conductometric hydrogen gas sensor and its response was tested and evaluated. It is demonstrated that addition of CuO clusters noticeably enhances the sensitivity of the pure WO3 thin film. With an increasing amount of CuO clusters the sensitivity of CuO/WO3 system rises further. When CuO clusters form a sufficiently thick and compact layer, the resistance response is reversed. Based on the sensorial behavior, conventional and near-ambient pressure X-Ray photoemission spectroscopies, and resistivity measurements, we propose that the sensing mechanism is based on the formation of nano-sized p-n junctions in between p-type CuO and n-type WO3. The advantages of the GAS technique for preparing sensorial and/or catalytically active materials are emphasized.
关键词： Hydrogen gas sensor,Gas aggregation cluster source,Magnetron sputtering,Tungsten oxide,Nanocomposites,Cupric oxide
更新于2025-09-10 09:29:36
-
Pd Nanoparticle Film on a Polymer Substrate for Transparent and Flexible Hydrogen Sensor
摘要： Alongside the rise in fully automated equipment and the wearable devices, there is currently a high demand for optically transparent and flexible gas sensors operating at room temperature. Nanoparticle films are ideal H2-sensing materials that can be coupled with flexible substrates because of their discrete nanogranular structure and unique interparticle electrical responsiveness. In this work, we present an optically transparent and flexible H2 sensor based on a Pd nanoparticle film, prepared on a polyethylene terephthalate sheet using a straightforward nanocluster deposition technique. Hundreds of bending cycles demonstrated that the sensor has good electrical stability and mechanical robustness without significant degradation in H2-sensing performance. The H2-sensing behaviors under bent state were systematically evaluated. The loading of tensile and compressive strains under bent state produced a positive and negative influence, respectively, on the sensing performances. The possible influence mechanism of the tensile and compressive strains on H2-sensing performance was attributed to the changes in the percolation network topology and the interparticle space induced by the strains. The ability to detect an H2 concentration as low as 15 ppm, dynamic response range as wide as 0?10% and sub-10 s response time were achieved. In addition, the sensor can be operated in the relative humidity range of 0?90% at room temperature. These results demonstrate that the sensor exhibits significant potential for next-generation transparent and flexible H2 detector.
关键词： flexible,palladium nanoparticle,transparent,hydrogen gas sensor,nanogranular
更新于2025-09-09 09:28:46