Tunable Synthesis of Cuprous and Cupric Oxide Nanotubes from Electrodeposited Copper Nanowires

Abstract

Polycrystalline copper oxide nanostructures with different valence/oxidation states (i.e., Cu2O and CuO) were readily synthesized by thermal oxidation of single crystalline copper nanowires at relative low operating temperature (200 to 300 degrees C). Operating temperature of 200 to 250 degrees C in air oxidized copper to Cu2O and further increased temperature (i.e., 300 degrees C) led to form CuO nanostructures. The morphology of nanostructures significantly altered from nanowires to nanotubes which might be attributed to Kirkendall effect. The electrical resistivity of single copper nanowire, Cu2O and CuO nanotube were determined to be 3.4 x 10(-4), 33, and 211 omega cm, respectively.

Synthesis and characterization of nano-CuO and CuO/TiO 2 photocatalysts

“…On the other hand, due to their shape-and size-dependent properties, one needs to consider the precise controllability of copper oxide chemical composition, size, shape and surface chemistry to obtain its chemical and physical properties as desired. Many recent efforts have been devoted to the synthesis of copper oxide nanostructures with various morphologies, such as particles [5][6][7][8], hollow spheres [1,9], rods [10,11], tubes [12], wires [13,14] and flowers [15]. Different methods have been used to synthesize copper oxides, such as using templates, microwave-assistance, thermal decomposition and sonochemical and hydrothermal reactions.…”

Ionic-Diffusion-Driven, Low-Temperature, Solid-State Reactions Observed on Copper Sulfide Nanowires

“…Although the solid-state formation of hollow inorganic structures derived from the reaction of core/shell starting materials by the Kirkendall effect has been previously reported, ,,, the temperature at which the RIT forms is highly unusual. This low-temperature reaction is likely enabled by the high diffusivity of Cu + .…”

“…This differentiates the structures from the common zerodimensional analogues known as "rattle" or "yolk-shell" nanostructures, or nanotubes formed from core/shell nanowires, both of which generally form via a normal Kirkendall process in which the core material is consumed and diminished during the reaction process. 6 Although the solid-state formation of hollow inorganic structures derived from the reaction of core/shell starting materials by the Kirkendall effect has been previously reported, 6,10,29,30 the temperature at which the RIT forms is highly unusual. This low-temperature reaction is likely enabled by the high diffusivity of Cu + .…”

Selective transformation of Cu nanowires to Cu2S or CuS nanostructures and the roles of the Kirkendall effect and anion exchange reaction

“…To justify this assumption, Cu 2 O and CuO nanostructures were synthesized by the thermal oxidation of Cu nanowire [19], and the products were reacted with 0.1 M thiourea at 90 C for 10 h for sulfurization. Fig.…”