Cu-Doped ZnO Nanoneedles and Nanonails: Morphological Evolution and Physical Properties

Abstract

Controlling novel morphologies and developing effective doping strategies are two important tasks for advancing ZnO-based nanomaterials. We have grown vertically aligned Cu-doped ZnO nanonails and nanoneedles and observed a continuous evolution between various morphologies. Selecting source compositions and regulating vapor and gas pressures modify the Ehrlich-Schwoebel energy barrier for the surface diffusion and determine the morphologies. X-ray diffraction study indicates a decrease in the lattice parameter after the Cu doping. Photoluminescence measurements taken on both doped and undoped samples show that, in the Cu-doped ZnO nanostructures, the band-edge UV emission and the broad green emission are red-shifted by ∼7 and 20 nm, respectively. X-ray photoelectron spectroscopy study revealed a higher level of oxygen vacancies in nanoneedles, which was found to enhance the green emission. Room-temperature ferromagnetism was also observed in Cu-doped ZnO nanomaterials. On the basis of the strong correlations between structures and properties, we demonstrate that the morphologies and the optical and magnetic characteristics can be tailored to a large degree in transition-metal-doped ZnO nanostructures.

Field emission and room temperature ferromagnetism properties of triangle-like ZnO nanosheets

“…2(a) is shown in Fig. 2 In our experiments, CuO powder was added into the reactant mixture powder, which is supposed to play a critical role in the formation of triangle-like ZnO nanosheets [14,15]. The growth mechanism of triangle-like nanosheets was thought to be the growth and coalescence of nanobranches process [16].…”

The advanced removal of benzene from aerosols by photocatalytic oxidation and adsorption of Cu–TiO 2 /PU under visible light irradiation

“…The CuO oxide could be produced from the decomposition of Cu(NO 3 ) 2 under the effect of the UV irradiation and calcination temperature, during the preparation processes [15,25,26]. The UV irradiation and oxalic acid, rolled as a cleaner for the cleaning process, could also reduce Cu 2+ into Cu + during the decomposition of Cu(NO 3 ) 2 , to form Cu 2 O [26][27][28][29]. The obtained HRTEM results confirm the existences of CuO and Cu 2 O blending with TiO 2 (Fig.…”

Structural and optical characterization of Zn0.95−xMg0.05CuxO nanoparticles

“…[5,6]. Among the different metallic doping elements, Cu as dopant is important because, (i) it is a prominent luminescence activator, which can modify the luminescence of ZnO crystals by creating localized impurity levels [7] (ii) it has many physical and chemical properties that are similar to those of Zn and (iii) it can change the microstructure and the optical properties of the ZnO system [8]. Moreover, tuning of chemical and physical properties of ZnO may be achieved with Cu doping into ZnO lattice.…”