Epitaxial growth of hyperbranched Cu/Cu2O/CuO core-shell nanowire heterostructures for lithium-ion batteries

Abstract

The careful design of nano-architectures and smart hybridization of expected active materials can lead to more advanced properties. Here we have engineered a novel hierarchical branching Cu/Cu 2 O/CuO heteronanostructure by combining a facile hydrothermal method and subsequent controlled oxidation process. The fine structure and epitaxial relationship between the branches and backbone are investigated by high-resolution transmission electron microscopy. Moreover, the evolution of the branch growth has also been observed during the gradual oxidation of the Cu nanowire surface. The experimental results suggest that the surface oxidation needs to be performed via a two-step exposure process to varying humidity in order to achieve optimized formation of a core-shell structured branching architecture. Finally, a proof-of-concept of the function of such a hierarchical framework as the anode material in lithium-ion batteries is demonstrated. The branching core-shell heterostructure improves battery performance by several means: (i) The epitaxially grown branches provide a high surface area for enhanced electrolyte accessibility and high resistance to volume change induced by Li + intercalation/extraction; (ii) the core-shell structure with its well-defined heterojunction increases the contact area which facilitates effective charge transport during lithiation; (iii) the copper core acts as a current collector as well as providing structural reinforcement.

Highly Luminescent Heterostructured Copper‐Doped Zinc Sulfide Nanocrystals for Application in Cancer Cell Labeling

“…TEM images and their fast Fourier transforms (FFTs) in Figure show that the particles are monocrystalline. The rotational averages (Figure e) of the FFTs show several peaks, which indicate the presence of a few compounds: ZB ZnS, hexagonal CuS, and hexagonal Cu 2 S. We ascribe the unassigned peaks to (partially) oxidized zinc or copper compounds …”

“…The rotational averages (Figure 2e)o ft he FFTss how several peaks, which indicate the presence of afew compounds:ZBZnS, hexagonal CuS, and hexagonal Cu 2 S. We ascribe the unassigned peaks to (partially) oxidized zinc or coppercompounds. [20,21]…”

CuO Nanoplates for High‐Performance Potassium‐Ion Batteries

“…As shown in Figure S8 (Supporting Information), the XPS peaks for Cu2p 1/2 and Cu 2p 3/2 are observed at 951.8 and 932.0 eV without a shake‐up satellite peak, suggesting that the external CuO nanoplates of the electrode have converted to Cu (I) when discharged to 0.7 V. When the electrode discharged to 0.01 V, its two XPS peaks at 951.6 and 931.7 eV are ascribed to metallic Cu (0) . Furthermore, the XPS peaks of the intermediate at fully charged state are centered at 952.2 and 932.3 eV, which are in agreement with Cu2p 1/2 and Cu 2p 3/2 , respectively, of Cu (I) . These results confirm that the potassiation process of the CuO anode in the first discharge consists of two main steps including the successive formation of KCuO and Cu, and then the depotassiation process is the oxidation of the Cu nanoparticle to Cu 2 O.…”

Hyper-Branched Cu@Cu2O Coaxial Nanowires Mesh Electrode for Ultra-Sensitive Glucose Detection.

“…15 Moreover, the smart integration of different materials in nanoscale can create more homogenous/heterogeneous junctions and large surface area to gain the novel functions and improve performance which cannot be realized from each of the components separately. [16][17][18][19] For superb performance enzymeless glucose sensors, such 3D material offers several potential advantages as the following: (i) 1D NW backbone effectively shortens the electron-tunneling distance Scheme 1. Two step synthesis process for hierarchical Cu@Cu 2 O NS-NW nanostructures and its application in glucose monitoring.…”