Microstructure Dependence of Hydrogen Sensing Properties of Palladium Functionalized Tungsten Oxide Films

2012 ◽  
Vol 1406 ◽  
Author(s):  
Meng Zhao ◽  
Jian-Xing Huang ◽  
Chung-Wo Ong
Keyword(s):  
Surface Roughness ◽  
Tungsten Oxide ◽  
Recovery Time ◽  
Film Surface ◽  
Sensor Technology ◽  
Sensing Properties ◽  
Hydrogen Sensing ◽  
Palladium Coating ◽  
Detection Response ◽  
Sputtering Pressure

ABSTRACTTungsten oxide (WO3) films were prepared by using magnetron sputtering. Substrate temperature and sputtering pressure were adjusted to vary the microstructure. The films were found to contain nanoclusters; while their size L, and porosity θ and surface roughness zRMS of the film can be varied. After adding a palladium coating on the film surface, the hydrogen (H2) sensing properties of the films, including sensitivity of detection, response time and recovery time were measured. Their dependences on L, θ and zRMS were analyzed and interpreted. The information achieved is useful for improving H2 sensor technology.

Sputtering pressure dependence of hydrogen-sensing effect of palladium films

2009 ◽  
Vol 24 (6) ◽  
pp. 1919-1927 ◽  
Author(s):  
Chung Wo Ong ◽  
Yu Ming Tang
Keyword(s):  
Electrical Resistivity ◽  
Magnetron Sputtering ◽  
Mean Free Path ◽  
Induced Response ◽  
Resistivity Ratio ◽  
Hydrogen Sensing ◽  
The Mean ◽  
Sputtering Pressure ◽  
Specific Volumes ◽  
Hydride Phases

The electrical resistivity ρ of palladium (Pd) films prepared by using magnetron sputtering at different pressures φ ranging from 2 to 15 mTorr showed very different hydrogen (H)-induced response. This reaction is because the mean free path of the particles in vacuum changes substantially with φ, such that the structure of the deposits is altered accordingly. A film prepared at a moderate φ value of 6 mTorr has a moderate strength. After a few hydrogenation-dehydrogenation cycles, some cracks are generated because of the great difference in the specific volumes of the metal and hydride phases. Breathing of the cracks in subsequent switching cycles occurred, which led to the response gain of ρ, defined as the resistivity ratio of the dehydrogenated-to-hydrogenated states during a cycle, to increase to 17. This result demonstrates the attractiveness of using the Pd films in H2 detection application. The H-induced resistive response of the films prepared at other φ values was found to be much smaller.

The Microstructure and Electrical Property of Porous Cu Film on Soft PVDF Substrate

2012 ◽  
Vol 472-475 ◽  
pp. 1451-1454
Author(s):  
Xue Hui Wang ◽  
Wu Tang ◽  
Ji Jun Yang
Keyword(s):  
Electrical Properties ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
X Ray ◽  
Cu Films ◽  
Cu Film ◽  
Diffraction Peaks ◽  
Sputtering Pressure ◽  
Effect Method

The porous Cu film was deposited on soft PVDF substrate by magnetron sputtering at different sputtering pressure. The microstructure and electrical properties of Cu films were investigated as a function of sputtering pressure by X-ray diffraction XRD and Hall effect method. The results show that the surface morphology of Cu film is porous, and the XRD revealed that there are Cu diffraction peaks with highly textured having a Cu-(220) or a mixture of Cu-(111) and Cu-(220) at sputtering pressure 0.5 Pa. The electrical properties are also severely influenced by sputtering pressure, the resistivity of the porous Cu film is much larger than that fabricated on Si substrate. Furthermore, the resistivity increases simultaneously with the increasing of Cu film surface aperture, but the resistivity of Cu film still decreases with the increasing grain size. It can be concluded that the crystal structure is still the most important factor for the porous Cu film resistivity.

Hydrogen sensing properties of Pt-Au bimetallic nanoparticles loaded on ZnO nanorods

2017 ◽  
Vol 241 ◽  
pp. 895-903 ◽  
Author(s):  
Faying Fan ◽  
Jiajun Zhang ◽  
Jiao Li ◽  
Na Zhang ◽  
RunRun Hong ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Zno Nanorods ◽  
Sensing Properties ◽  
Hydrogen Sensing

scholarly journals Optical Hydrogen Sensing Properties of Nanostructured Pd/MoO3 Films

2011 ◽  
Vol 9 (1) ◽  
pp. 16-20 ◽  
Author(s):  
M. H. Yaacob ◽  
J. Yu ◽  
K. Latham ◽  
K. Kalantar-zadeh ◽  
W. Wlodarski
Keyword(s):  
Sensing Properties ◽  
Hydrogen Sensing

scholarly journals Synthesis, Characterization, and NH3 Sensing Properties of (Zn0.7 Mn0.3-x Cex Fe2O4) Nano-Ferrite

2021 ◽  
Vol 2114 (1) ◽  
pp. 012040
Author(s):  
Laith Saheb ◽  
Tagreed M. Al-Saadi
Keyword(s):  
Recovery Time ◽  
Particle Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Properties ◽  
Auto Combustion ◽  
Cubic Structure ◽  
Sensing Characteristics ◽  
Combustion Technique ◽  
Higher Sensitivity

Abstract This study includes the preparation of novel nano ferrite (Zn0.7 Mn0.3-x Cex Fe2O4) by using the auto combustion technique. For the following molar values, the percentage x was calculated: 0.0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3. The nano-ferrite was calcined for 2 hours at 500°C. The energy dispersive x-ray spectroscopy (EDX), X-ray diffraction (XRD) and field emission scanning electron microscopy FE-SEM was used to examine structural, morphological, and sensing properties. The spinel cubic structure was revealed by XRD findings. The particle distribution was shown to contain voids by FE-SEM. The testing of sensing characteristics to NH3 gas indicated that the synthesized nano-ferrite has a small response time ranging from (15.3-25.2) s as well as a small recovery time between (36-58.5) s, also has a higher sensitivity of about 72.23%.

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