The self-assembly of octahedral Cu_xO and its triethylamine-sensing properties

Cu₂O with series adjustable octahedral morphologies was prepared via a simple, fast, and template-free method. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy are used to characterize the structure and morphology. The evolution and formation mechanism of these morphologies is discussed in detail. An assembly mode of this morphology is proposed. The hollow octahedral CuO was obtained after the heat-treatment of the octahedral Cu₂O. Analysis of gas sensing properties revealed that hollow octahedral CuO shows a high response to triethylamine with a low detection limit (10 ppm), good selectivity, and long-term stability. Finally, the gas sensing mechanism is also proposed.