• Journal of Hydrogen and New Energy
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• v.16 no.1
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• pp.9-16
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• 2005

We studied the electrochromic properties of hydrated amorphous ruthenium oxide ($RuO_2{\cdot}xH_2O$) thin films using in-situ Raman spectroscopy during electrochemical charging/discharging cycles. We have found that the principal effect of hydrogen insertion into $RuO_2{\cdot}xH_2O$ is reduction of $Ru^{4+}\;to\;Ru^{3+}$, and not formation of new bonds involving hydrogen. We compared the changes in the Raman spectrum of a gasochromic $Pd/RuO_2{\cdot}xH_2O$ film as it is exposed to hydrogen gas with that of electrochemical hydrogen insertion. We tested the changes in the optical transmission of the $Pd/RuO_2{\cdot}xH_2O$ film when exposed to hydrogen gas.

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.283-286
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• 2012

This paper presents the optical hydrogen sensor based on transparent 3C-SiC membrane and photovoltaic effect. Gasochromic materials of Pd and Pd/$WO_3$ were deposited by sputter on 3C-SiC membrane for gas sensing area. Gasochromic materials change to transparency by exposure to hydrogen. The variations of light intensity by hydrogen generate the photovoltaic of P-N junction between N-type 3C-SiC and P-type Si. Single layer of Pd shows higher photovoltaic compared with Pd/$WO_3$. However, phase transition from ${\alpha}$ to ${\beta}$ is shown at 6 %. Pd/$WO_3$ structure show the more linear response to hydrogen range of 2 % ~10 %. Also, almost 2 times fast response and recovery characteristics are shown at Pd/$WO_3$. These fast performances are come from the fact that Pd promoted the chemical reaction between hydrogen and $WO_3$.