Controlled Synthesis of Cu and Cu₂O NPs and Incorporation of Octahedral Cu₂O NPs in Cellulose II Films.

Alireza Eivazihollagh,Christina Dahlström,Håkan Edlund,Magnus Norgren

doi:10.3390/nano8040238

Alireza Eivazihollagh, Christina Dahlström + Show 2 more

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https://doi.org/10.3390/nano8040238

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Journal: Nanomaterials	Publication Date: Apr 14, 2018
Citations: 9	License type: CC BY 4.0

Affiliation: Mid Sweden University

Abstract

In this study, Cu and Cu2O nanoparticles (NPs) were synthesized through chemical reduction of soluble copper-chelating ligand complexes using formaldehyde as a reducing agent. The influence of various chelating ligands, such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and a surface-active derivative of DTPA (C12-DTPA), as well as surfactants (i.e., hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium chloride (DoTAC), sodium dodecyl sulfate (SDS), and dimethyldodecylamine-N-oxide (DDAO)), on morphology and the composition of produced NPs was investigated. In the absence of surfactants, spherical copper particles with polycrystalline structure could be obtained. X-ray diffraction (XRD) analysis revealed that, in the presence of EDTA, the synthesized NPs are mainly composed of Cu with a crystallite size on the order of 35 nm, while with DTPA and C12-DTPA, Cu2O is also present in the NPs as a minority phase. The addition of ionic surfactants to the copper–EDTA complex solution before reduction resulted in smaller spherical particles, mainly composed of Cu. However, when DDAO was added, pure Cu2O nano-octahedrons were formed, as verified by high-resolution scanning electron microscopy (HR-SEM) and XRD. Furthermore, a hybrid material could be successfully prepared by mixing the octahedral Cu2O NPs with cellulose dissolved in a LiOH/urea solvent system, followed by spin-coating on silica wafers. It is expected that this simple and scalable route to prepare hybrid materials could be applied to a variety of possible applications.

Highlights

Controllable synthesis of metal and metal oxide nanoparticles (NPs) with a specific morphology and chemical composition has been at the forefront of nanoscience and nanotechnology research [1,2,3,4]
Numerous chemical syntheses of Cu and Cu2O NPs have made use of a variety of chelating agents such as ethylenediaminetetraacetic acid (EDTA) [2,8], nitrilotriacetic acid (NTA) [2], tartrate [8], citrate [8,13], and NH3 [9] to suppress the formation of Cu(OH)2 at high pH, which is required for CH2O to act as a reducing agent [2,8]
As seen in the high-resolution scanning electron microscopy (HR-SEM) images, the copper particles obtained in solutions containing diethylenetriaminepentaacetic acid (DTPA) and C12-DTPA have rougher surfaces compared to the ones synthesized in the presence of EDTA (Figure 1)

Summary

Introduction

Controllable synthesis of metal and metal oxide nanoparticles (NPs) with a specific morphology and chemical composition has been at the forefront of nanoscience and nanotechnology research [1,2,3,4]. The chemical reduction method is a simple, low-cost, and scalable technique that only requires a reducing agent to reduce copper salt to metallic Cu or cuprous oxide Cu2O NPs. Reducing agents used for this purpose include sodium borohydride [1,7,8], hydrazine [3,9,10], hydroxylamine [11,12], glucose [13,14], ascorbic acid [14,15], sodium ascorbate [3], or formaldehyde [2,8]. Great advances have been made in the preparation of Cu and Cu2O NPs, the synthesis strategies are time-consuming and costly due to the number of steps required, and the overall complexity of the preparation process still requires further improvements

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