Facile green synthesis of In₂O₃ bricks and its NO₂ gas sensing properties

Recently, metal oxide semiconductor based gas sensors have been used to monitor and maintain amount of toxic gases in environment. Use of In₂O₃ nano/microstructures have been increased as a heterogeneous catalyst for gas sensing due to its high response, good selectivity, short response and recovery time. In the present work, synthesis of In₂O₃ bricks was carried by a hydrothermal method using biomolecule as green product. The effect of precursor concentrations of In₂O₃ thin film was studied in this particular work. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Photoluminescence (PL), scanning electron microscope (SEM), Field emission scanning electron microscope (FE-SEM) and Brunauer–Emmett–Teller (BET) analyses were used for structural, optical, morphological and surface analysis characterizations. The In₂O₃ thin film displays high sensitivity and selectivity due to its active sites present on sensing layer. The results assures that optimized In₂O₃ thin films exhibit a high response with very low response and recovery time about 600 for NO₂ gas.