One-step, template-free hydrothermal synthesis of CuO tetrapods

The present investigation reports one-step template-free hydrothermal synthesis of CuO tetrapods (CuO-T) and its characterization. The CuO tetrapods have been prepared in moderate condition without using any surfactant. The prepared sample was characterized by powder X-ray diffraction (PXRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, UV–vis–NIR (DRS) spectroscopy and Photoluminescence (PL) spectroscopy. The X-ray diffraction and Fourier transform infrared spectrum analysis confirm clearly the formation of a pure phase high-quality CuO with monoclinic crystal structure. X-ray peak broadening analysis was used to evaluate the average crystallite size (∼30 nm) and lattice strain by the Williamson–Hall (W–H) method. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) result reveals that the particles are tetrapods in shape with an average length ∼50 nm. Additionally the optical properties were investigated by using UV–vis reflectance spectra with considerable blue-shift in the optical band gap (Eg = 1.45 eV) due to quantum confinement effect. Photoluminescence (PL) spectrum showed both UV as well as visible emission peaks indicating their good optical properties.