Enhanced sensing performance of p-n heterojunction of In₂O₃-Cu₂O for isopropanol detection

An efficient isopropanol sensor with high sensitivity, rapid response and recovery times is essential for environmental monitoring and human health. A nanoscale p-n heterojunction of heterostructured In₂O₃-Cu₂O was prepared using the chemical precipitation method and solid-state mixing, with different weight percentages of In₂O₃ and Cu₂O. The morphologies, microstructure, composition, and surface area of the material were analyzed using various characterization techniques. The gas sensing performance was investigated systematically using a static gas chamber with multiple target gases at several temperatures. The nanocomposite IC-90 showed a high sensing response of 15.62 towards 100 ppm IPA at an operating temperature of 250 °C. Also, the sensor IC-90 responds rapidly in 19 s and recovers in 200 s. The combined effect of the catalytic property of Cu₂O, enhanced active centers through the formation of p-n heterojunction, and the high surface area of sensing material IC-90 attributed to the improved sensing performance towards isopropanol.