Extremely small methanol sensor with micro/nano porous Au-Pt electrodes for compact DMFC applications

Extremely miniaturized methanol sensor was successfully developed and characterized. In order to minimize methanol sensor, the sensor was newly fabricated by using two circular porous Au electrodes with Pt nano-particles (micro/nano porous Au-Pt). The micro/nano porous Au-Pt electrode acts as a gas diffusion layer and current collector in the extremely miniaturized methanol sensor. The sensor was designed to be easily fabricated by hot pressing two these electrodes with Nafion film. Cyclic voltammetry and amperometric measurements were performed to confirm the electrochemical characteristics of the fabricated sensor. The fabricated sensor showed excellent response current to a wide temperature ranged from 20 to 100°C and a methanol concentration ranged from 0 to 2 M. It exhibited a sensitivity of 9.6 mA/mM·cm² and a fast response time less than 10 seconds, which was the fastest in the reported ones. Its size was extremely miniaturized, approximately 0.25 cm².