Novel synthesis of CuO nanofiber balls and films and their UV-visible light filteration property

Self-assembled cupric oxide (CuO) nanofiber balls and films were synthesized via a facile solvothermal route directly from cupric acetate monohydrate (Cu(CH₃COO)₂·H₂O) in water and ethanol without any chemical additions or high temperature treatment. The CuO balls with size of 150 nm-1.5 μm had rough surfaces which consisted of lots of about 10 nm nanofibers in diameter. The sizes of CuO balls were controllable by changing reaction time and volume ratio of water to ethanol. CuO nanofiber films were prepared with the aid of the in situ hydrolysis of Cu(CH₃COO)₂·H₂O coating layer on a substrate at 60 °C. CuO films showed excellent UV-visible light filteration property and could be used as a potential candidate of UV-visible light filter. Compared with traditional method to fabricate CuO films, neither precursor nor Cu substrate was needed in this study. This technique could be used to produce CuO films without being confined to our template and to produce CuO powders in large scale with low cost.