Synthesis of In2O3 nano powder by Aloe barbadensis Miller extract and its application as H2S gas sensor

In this work In2O3 nanocrystalline powder has been synthesized with cubic structure by simple, cost effective and eco friendly route using Aloe Vera barbadensis Miller species available in our region having orange colour flowers. X-ray diffraction (XRD ) and EDAX confirmed that synthesis is viable and complete. The synthesized nano powder was used as functional materials for fabrication of thick films on alumina substrate using standard screen printing technique. The fabricated thick films were fired at temperatures 600,700 and 800°C respectively. The film fired at 700°C shows low resistivity and high response to H2S gas.XRD of powder and films confirmed base centered cubic phase with (222) plane orientation.SEM of powder shows cauliflower like structure. Electrical measurement of film showed n-type semiconductor. Thick films fired at 700°C showed highest sensitivity towards 100 ppm concentration of hydrogen sulphide gas at low temperature 150°C.The sensor exhibits quick response in ∼ 6 second.