Pt/WO₃ Nano−Particles Dispersed PEDOT/PSS Hybrid Hydrogen Gas Sensor

Hydrogen gas sensor is of great demand for the safe use of the new generation energy source. To date, many types of hydrogen sensor have been proposed and developed. However, most of them including semiconductor and catalytic combustion hydrogen sensors require high−temperature such as above 200 °C for the operation. Moreover, hydrogen gas sensors should be flexible enough to be fabricated in any shapes, considering the application for leak detection in transport pipes and storage tanks with complex geometries. Here, we report a successful development of a noble hydrogen sensor with a flexibility and electrical and optical detection by combining a well−known conductive polymer, PEDOT:PSS, and a gasochromic material, Pt/WO₃.

Pt/WO₃ nano−particles were synthesized by sol-gel process. The Pt/WO₃ nano−particles were dispersed in PEDOT/PSS aqueous dispersion. To obtain the hybrid thin film sensor, the aqueous dispersion was casted on a glass substrate using spin-coat technique. The hydrogen gas detecting ability of the thin film was evaluated by UV−Visible spectroscopy system as an optical property and digital multimeter as an electrical resistance combined with a H₂, O₂, and N₂ gas control system. The gases were exchanged in a certain interval between 100% H₂ gas and synthetic air (80% N₂ + 20% O₂). As a result, a decrease in transmittance and an increase in electrical resistance were detected under H₂ gas exposure. Under synthetic air, those were recovered to the initial state, indicating the response is reversible. We successfully fabricated a flexible gas sensor which can detect hydrogen by optical and electrical signals for the first time. The details of fabrication and measurements will be presented in our poster.