Catalyst-free direct vapor-phase growth of Zn1−xCu x O micro-cross structures and their optical properties

Abstract

We report a simple catalyst-free vapor-phase method to fabricate Zn1−xCuxO micro-cross structures. Through a series of controlled experiments by changing the location of the substrate and reaction time, we have realized the continuous evolution of product morphology from nanorods into brush-like structures and micro-cross structures at different positions, together with the epitaxial growth of branched nanorods from the central stem with the time extended. The growth mechanism of the Zn1−xCuxO micro-cross structures has been proposed to involve the synthesis of Cu/Zn square-like core, surface oxidation, and the secondary growth of nanorod arrays. By the detailed structural analysis of the yielded Zn1−xCuxO samples at different locations, we have shown that the CuO phases were gradually formed in Zn1−xCuxO, which is significant to induce the usual ZnO hexagonal structures changing into four-folded symmetrical hierarchical micro-cross structures. Furthermore, the visible luminescence can be greatly enhanced by the introduction of Cu, and the observed inhomogeneous cathode luminescence in an individual micro-cross structure is caused by the different distributions of Cu.

Cu-implanted ZnO nanorods array film: An aqueous synthetic approach

“…Cu doped ZnO nanorods showed red shift in E 2 high mode as compared to pure nanorods (Fig. 4b), which was clear indication of incorporation of Cu ions into ZnO nanorods lattice, this kind of red shift was also observed previously [20,41]. The reason behind this frequency shift is similar to explain by Samanta et al [42].…”

In‐situ Glycine Sensor Development Based ZnO/Al2O3/Cr2O3 Nanoparticles

“…Figure (a) shows Zn2p XPS spectrum with two spin orbitals Zn2p 3/2 and Zn2p 1/2 corresponding binding energy 1022.2 and 1045.4 eV respectively. The spin energy separation of Zn2p level is equal to 23.2 eV representing the oxidation sate of Zn 2+ ,. In Figure (b), the O1s shows one high intense peak at 531.0 eV indicating lattice oxygen with oxidation state of O 2− in sample ZnO/Al 2 O 3 /Cr 2 O 3 NPs ,.…”

Bimetallic Fe‐Promoted Catalyst for CO‐Free Hydrogen Production in High‐Temperature‐Methanol Steam Reforming

“…This shift to higher binding energy in Al 2p corresponds to aluminum hydroxide species . Lastly, Zn2p spectra in Figure e shows peaks at 1023±0.1 eV and 1046±0.1 eV which correspond to Zn 2p 3/2 and Zn2p 1/2 respectively …”

“…[25] Lastly, Zn2p spectra in Figure 2e shows peaks at 1023 � 0.1 eV and 1046 � 0.1 eV which correspond to Zn 2p 3/2 and Zn2p 1/2 respectively. [26] Temperature-programmed reduction profiles of Al 2 O 3 À ZnÀ ZrO 2 supported monometallic as well as bimetallic catalysts are presented in Figure 3(a-e). All catalysts with 3 % total metal loading were used.…”