Preparation and chemiresistive properties of nanostructured materials

Several synthetic methods for the preparation of nanostructured materials for gas sensor applications were presented. The chemiresistive properties of these materials and the role of humidity in gas sensing were also analyzed. These methods are based on the deposition of metal on a substrate followed by oxidation. Some of these techniques include rheotaxial growth and thermal oxidation (RGTO), low temperature physical vapor deposition (LTPVD) and sputtering-oxidation method. The samples of SnO2 studied at elevated temperatures with different humidities shows that increase in humidity results in a decreased resistance and increased electron affinity.