Main content area

Ultrasensitive Electrochemical Methane Sensors Based on Solid Polymer Electrolyte-Infused Laser-Induced Graphene

Dosi, Manan, Lau, Irene, Zhuang, Yichen, Simakov, David S. A., Fowler, Michael W., Pope, Michael A.
ACS applied materials & interfaces 2019 v.11 no.6 pp. 6166-6173
ambient temperature, cost effectiveness, electrochemistry, electrodes, electrolytes, emissions, films (materials), gases, graphene, greenhouse gases, infrastructure, ionic liquids, methane, mining, nanoparticles, palladium, prototypes, relative humidity, sensors (equipment), surface area, thermoplastics
Methane is a potent greenhouse gas, with large emissions occurring across gas distribution networks and mining/extraction infrastructure. The development of inexpensive, low-power electrochemical sensors could provide a cost-effective means to carry out distributed sensing to identify leaks for rapid mitigation. In this work, we demonstrate a simple and cost-effective strategy to rapidly prototype ultrasensitive electrochemical gas sensors. A room-temperature methane sensor is evaluated which demonstrates the highest reported sensitivity (0.55 μA/ppm/cm²) with a rapid response time (40 s) enabling sub-ppm detection. Porous, laser-induced graphene (LIG) electrodes are patterned directly into commercial polymer films and imbibed with a palladium nanoparticle dispersion to distribute the electrocatalyst within the high surface area support. A pseudo-solid-state ionic liquid/polyvinylidene fluoride electrolyte was painted onto the flexible cell yielding a porous electrolyte, within the porous LIG electrode, simultaneously facilitating rapid gas transport and enabling the room temperature electro-oxidation pathway for methane. The performance of the amperometric sensor is evaluated as a function of methane concentration, relative humidity, and tested against interfering gases.