Comparison of Methane Gas Sensing of Zinc Oxide Film Fabricated by Successive Ionic Layer Adhesion and Reaction with Mq4 Gas Sensor
Emmanuel A. Florido1*, Veronica M. Mercado1
1Institute of Mathematical Sciences and Physics, University of the Philippines Los Banos, Los Banos, Laguna, Philippines
* Presenter:Emmanuel A. Florido
Zinc oxide (ZnO) film was fabricated by successive ionic layer adsorption and reaction (SILAR) with 200 cycles of alternate dipping in sodium zincate solution and hot water bath maintained at 900C. The film was annealed at 3000C and later sensitized using palladium chloride (PdCl2). The methane gas sensing response of the fabricated film was compared to an MQ4 methane gas sensor. Analytical grade methane was supplied from standard methane gas canisters. The required amount of calibrated gas was injected to an airtight chamber containing the sensors using a gas syringe. The sensors were tested using two concentration ranges: 10 to 60 ppm and 618 to 5000 ppm. The ZnO/Pd film exhibited a sensitivity of 1 mV per 10 ppm while the MQ4 sensor showed a sensitivity of 0.8 mV per 10 ppm in the 618 to 5000 ppm. In the 10 to 60 ppm range the ZnO/Pd film had a sensitivity of 1mV per ppm. The MQ4 sensor failed to show gas sensitivity and had low correlation between voltage output and concentration and concentration in the low range.

Keywords: zinc oxide, MQ4, SILAR, sensitivity, gas sensor