Synergistic effect of CeO2 nanoparticles and WO3 nanowires in gas sensing applications

The search for a highly selective ethanol sensor is still an open challenge. Metal oxides still face selectivity issues when it comes to gas sensing especially in case of ethanol. Keeping this in sight, in this work we explore the sensing properties of WO3 nanowires grown via the aerosol assisted chemical vapour deposition and decorated with CeO2 nanoparticles by drop casting. The nanocomposites were characterized by X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray, photoluminescence, Raman and X-ray photoelectron spectroscopies. Upon exposure to different gas analytes, the electrical characterization showed that sensors responded well to ethanol both under dry and humid conditions (RH= 50%, 25 degrees C), though the response towards ethanol decreased in humid atmospheres. The long-term stability was studied, and a gas sensing mechanism is introduced and discussed.