Development of Pd/TiO2 Porous Layers by Pulsed Laser Deposition for Surface Acoustic Wave H2 Gas Sensor

Nanomaterials

Cristian Viespe¹  Izabela Constantinoiu¹ 

[1] National Institute for Laser, Plasma and Radiation Physics, Laser Department, Atomistilor 409, 077125 Magurele, Romania;

关键词: pulsed laser deposition (PLD);    surface acoustic wave (SAW);    hydrogen sensor;    porous morphology;    bilayer films;    Pd/TiO₂;   

DOI  :  10.3390/nano10040760

来源: DOAJ

【 摘 要 】

The influence of sensitive porous films obtained by pulsed laser deposition (PLD) on the response of surface acoustic wave (SAW) sensors on hydrogen at room temperature (RT) was studied. Monolayer films of TiO₂ and bilayer films of Pd/TiO₂ were deposited on the quartz substrates of SAW sensors. By varying the oxygen and argon pressure in the PLD deposition chamber, different morphologies of the sensitive films were obtained, which were analyzed based on scanning electron microscopy (SEM) images. SAW sensors were realized with different porosity degrees, and these were tested at different hydrogen concentrations. It has been confirmed that the high porosity of the film and the bilayer structure leads to a higher frequency shift and allow the possibility to make tests at lower concentrations. Thus, the best sensor, Pd-1500/TiO₂-600, with the deposition pressure of 600 mTorr for TiO₂ and 1500 mTorr for Pd, had a frequency shift of 1.8 kHz at 2% hydrogen concentration, a sensitivity of 0.10 Hz/ppm and a limit of detection (LOD) of 1210 ppm. SAW sensors based on such porous films allow the detection of hydrogen but also of other gases at RT, and by PLD method such sensitive porous and nanostructured films can be easily developed.

【 授权许可】

Unknown