Preparation and ethanol sensing properties of flower-like cupric oxide hierarchical nanorods

Flower-like cupric oxide (CuO) hierarchical nanorods (petal size: 60–100 nm in diameter and 500–700 nm in length) were synthesized by wet chemical-assisted hydrothermal processing. The samples were characterized by field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The influence of hydrothermal temperature on the formation of CuO nanoflowers was investigated. Sensors based on CuO nanoflowers were fabricated by coating them on SiO2/Si substrate attached with Pt interdigitated electrodes. Sensing characteristics of the samples were measured and evaluated as a function of operating temperature and ethanol vapor concentration. The results revealed that the p-type semiconductor CuO nanoflowers based sensors exhibit high sensitivity and selectivity toward ethanol vapor with the optimum working temperature at about 230 °C.