Alcohol Sensor Based on Mg-STI zeolite Thick Films

Natural zeolite stilbite crystals are procured from Pune the near Pashan area in Maharashtra, India. The Ca-stilbite (Ca-STI) is characterized by X-ray diffraction, Elemental analysis, infrared spectroscopy and thermal analysis. The calcium ions in natural stilbites are replaced with magnesium ions via ion exchange process to have modified stilbite. Pristine and ion exchanged stilbite thick films are prepared via screen printing process and the prepared films are annealed at 6500C and used as sensors to test alcohols like ethanol and propanol. It is observed that due to the partial substitution of magnesium ions in Ca-STI structure operating temperatures shift to lower temperatures for both, ethanol and propanol. However, Mg-stilbite (Mg-STI) sensor gives more response to propanol than ethanol compared to Ca-STI sensor. The study reveals that presence of magnesium ions in Ca-STI results in lowering of operating temperatures. Mg-STI thick film sensor is an excellent alcohol sensor which can sense ethanol and propanol at much lower temperatures compared with pristine sensor with higher response to propanol compared to ethanol.