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

Abstract 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.