Solvent and catalyst-free synthesis of In₂O₃ octahedron using single-step thermal decomposition technique for NO₂ detection

In this article, a highly crystalline In₂O₃ octahedron has been synthesized by a single-step solvent and catalyst-free thermal decomposition method. The as-synthesized sample has been characterized using XRD, FESEM, HR-TEM, and XPS. The characterization results confirmed the formation of the cubic phase of the In₂O₃ sample with the octahedron morphology. The gas sensing characteristics of the In₂O₃ octahedron sample for oxidizing and reducing gases have been investigated systematically. The optimum operating conditions for selective detection of chemical inputs have been determined. Additionally, a maximum sensor response (~4252%) along with fast response (recovery) times ~30 s (13 s) has been obtained for NO₂ gas (30 ppm) at its operating temperature 200 °C. The results suggested that the In₂O₃ octahedron sensor proposes a promising candidate for NO₂ detection at its optimum operating temperature of 200 °C and can open up new ways to integrate these sensors with future electronic devices.