Low-temperature solution synthesis of CuO nanorods with thin diameter

CuO nanorods with thin diameter of about 5 nm were prepared at 50 °C with the assistance of polyethylene glycol (PEG) as growth directing agent, and these thin rods had a strong tendency to aggregate with parallel orientation. PEG was found to be effective for controlling the size of CuO, and the length of CuO nanorods was decreased by increasing the molecular weight of PEG. CuO nanoparticles with size ranging from 80 to 100 nm were produced if polyethylene oxide (PEO) 400,000 was employed. The CuO samples were characterized by SEM, TEM, and XPS techniques. The band gap of CuO nanorods is estimated to be 2.30 eV according to the UV–vis absorption spectrum, and such value is larger than that for bulk CuO probably due to the quantum confinement effect.

Graphical abstractCuO nanorods with diameter of about 5 nm were prepared at 50 °C via a solution method with the assistance of PEG molecules as the growth directing agent, and the optical band gap of such CuO nanorods was estimated to be 2.30 eV probably due to the quantum confinement effect.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Low-temperature solution synthesis of CuO nanorods with thin diameter of 5 nm. ► PEG molecules acted as growth directing agent. ► Length of CuO nanorods reduced with the molecular weight of PEG increasing. ► Optical band gap of such CuO nanorods was estimated to be 2.30 eV.