Syntheses of CuO nanostructures in ionic liquids

Abstract

A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route. Both nanoparticles (5 nm in size) and nanorods (5-10 nm in diameter and 50-100 nm in length) of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS) and nitrogen adsorption analysis. The morphologies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids. The growth mechanism of CuO nanostructures is investigated.CuO, nanostructures, ionic liquids, low-temperature solid-state route Metal oxides represent the most diverse class of materials with properties covering almost all aspects of materials science and physics in areas including superconductivity, ferroelectricity, magnetism, transparent conducting materials and gas sensors. A good example is crystalline copper oxide with nanometer-scale, an advanced material with wide potential applications as high-T c superconductors, organic catalysts, gas sensors, and lithium ions electrode materials [1] . Especially recently, single crystalline CuO nanorods have been used as anode materials for lithium ion battery and exhibit a high electrochemical capacity [2] . For these particular applications, the high surface-volume ratio and the nanometric size are expected to result in a tremendous improvement of chemical properties, thus rendering this material particularly appealing [1] .Many efficient approaches to prepare copper oxide thin film, nanotube, nanorods, and nanoparticles have been reported, such as MOCVD template method [1] , wet-chemistry route [2] , sonochemical preparation [3] , alkoxide-based preparation [4] , solid-state reaction [5] , solid-state reaction in the presence of surfactant polyethylene glycol (PEG) [6] , etc. Particularly, low-temperature solid-state route has been found to be a simple, efficient way and shows specific advantages, such as convenience, economical, less energy and material consumption and high yield [5][6][7][8] .Ionic liquids are salts composed of only ions which are liquid at relatively low temperatures (under 100℃). 1-n-butyl-3-methylimidazolium tetrafluoroborate (abbreviated as [BMIM] [BF 4 ], Scheme 1), as a room temperature ionic liquid, is air and moisture stable, neutral, non-volatile, and weakly coordinating. In addition, both its cation and anion can serve as templates or charge compensating groups in the syntheses. When an ionic liquid is used as a reaction solvent, the solute is solvated by ions only. Thus, the reaction proceeds in an environment totally different from that when water or ordinary organic solvents are used, and therefore, high selectivity is possible. Although their applications with these features are being vigorously explored as green solvents in organic synthesis, such as Friedel-Cr...

Sonochemical Synthesis of 0D, 1D, and 2D Zinc Oxide Nanostructures in Ionic Liquids and Their Photocatalytic Activity

“…[67] (sample 6), with the more strongly coordinating thiocyanate ion, were compared. Nanorods were obtained with diameters of 20 nm and lengths between 200 and 400 nm (sample 6).…”

“…It was proposed that the imidazolium cation interacts through the acidic 2-H proton rather than through the p system of the imidazolium core, with certain growth facets leading to the rodlike growth of ZnO. [67] For [C 8 mim][Tf 2 N] (sample 2) and [C 10 mim][Tf 2 N] (sample 3), which contain an acidic 2-H proton, nanorods were not obtained, rather spherical particles. Notably, on using an IL in which the acidic position was blocked by an alkyl group, such as in [EDimim][Tf 2 N] (sample 4), rod-shaped ZnO, with a diameter of 20 nm and a length of 50-200 nm, was still obtained.…”

Systematic Investigation on Morphologies, Forming Mechanism, Photocatalytic and Photoluminescent Properties of ZnO Nanostructures Constructed in Ionic Liquids

“…Recently, ionic liquids, a new class of solvents with ionic character, have been widely employed in organic reactions and electrochemical devices, because of their negligible vapor pressure, high ionic conductivity, and a large electrochemical window. – However, in contrast to successful applications in organic and electrochemistry, the use of ionic liquids in inorganic synthesis is still in its infancy. Most recently, the advantages of ionic liquids in inorganic synthesis have been gradually realized; a few inorganic materials, such as mesoporous silica and supermicroporous silica, iridium and gold nanoparticles, TiO 2 nanocrystals and microspheres, Te and CoPt nanorods, and so on, – have been fabricated in ionic liquids. However, to our best of knowledge, systematic investigations on the relationship between the structures of ionic liquids and the morphology of ZnO nanostructures have no report hitherto.…”

Shape-controlled synthesis of Cu2O nanoparticles with single-digit nanoscale void space via ionic liquid/metal sputtering and their photoelectrochemical properties

“…Cubic NPs with a size of ∼100 nm can be synthesized by microwave irradiation, 15) and large aggregates composed of NPs ∼50 nm in size can be obtained by the decomposition of copper complexes. 16,17) However, the use of RTILs for controlling the nanostructure (such as core-shell and hollow structures) of Cu 2 O NPs has not been extensively investigated. Recently, we reported the preparation of various metal NPs by sputter depositing metals in RTILs under reduced pressure (RTIL/metal sputtering).…”