CuO@In₂O₃/ZnO Core–Shell Nanorods for Triethylamine Detection at Room Temperature

Sensitive and stable triethylamine (TEA) gas sensors are desirable for environmental and human safety. However, the high operating temperature of the metal-oxide-based gas sensors poses a limitation on their wide applications. Herein, we fabricate an exceptional TEA gas sensor based on the core–shell heterostructure comprising crystalline CuO and amorphous In 2 O 3 /ZnO (CuInZnO) via a facile electrodeposition method. Remarkably, the optimum gas sensor (CuInZnO-3) exhibits an outstanding gas response (∼25) toward a 10 ppm TEA at room temperature. Moreover, CuInZnO-3 shows excellent selectivity, linear response, and stability. The superior sensing performance can be mainly ascribed to the unique core–shell nanorod heterostructure with a high specific surface area, allowing the formation of p–n junctions. The amorphous nature of the In 2 O 3 /ZnO shell also enriches the active oxygen on the surface and enhances gas adsorption.