An in situ X-ray absorption spectroscopy study of copper nanoparticles in microemulsion

Gomes, Washington C.M.; Neto, Alcides de Oliveira Wanderley; Pimentel, Patrícia Mendonça; Melo, D.M.A.; Silva, Fabiana Roberta Gonçalves e

doi:10.1016/j.colsurfa.2013.03.007

Cited by 14 publications

(11 citation statements)

References 28 publications

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“…Further comparison of the XANES spectrum of EDTA Au|mixed SAM|Cu with XANES data obtained from the literature for metallic copper and Cu 0 nanoparticles shows a significant negative shift of the onset energy of the absorption edge for both Cu 0 references (Figure 4 green line and dashed green line). 48,49 This shift supports an assignment of the +I oxidation state for the anchored copper species and rules out the +0 oxidation state. The relatively low onset energy of the absorption edge observed for modified electrode EDTA Au|mixed SAM|Cu might, however, be the result of the presence of a minor Cu 0 species besides the major Cu I species.…”

Section: Results and Discussionsupporting

confidence: 73%

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Elucidation of the Structure of a Thiol Functionalized Cu-tmpa Complex Anchored to Gold via a Self-Assembled Monolayer

Smits

Boer

et al. 2019

Inorg. Chem.

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The structure of the copper complex of the 6-((1-butanethiol)oxy)-tris(2-pyridylmethyl)amine ligand (Cu-tmpa-O(CH2)4SH) anchored to a gold surface has been investigated. To enable covalent attachment of the complex to the gold surface, a heteromolecular self-assembled monolayer (SAM) of butanethiol and a thiol-substituted tmpa ligand was used. Subsequent formation of the immobilized copper complex by cyclic voltammetry in the presence of Cu(OTf)2 resulted in the formation of the anchored Cu-tmpa-O(CH2)4SH system which, according to scanning electron microscopy and X-ray diffraction, did not contain any accumulated copper nanoparticles or crystalline copper material. Electrochemical investigation of the heterogenized system barely showed any redox activity and lacked the typical CuII/I redox couple in contrast to the homogeneous complex in solution. The difference between the heterogenized system and the homogeneous complex was confirmed by X-ray photoelectron spectroscopy; the XPS spectrum did not show any satellite features of a CuII species but instead showed the presence of a CuI ion in a ∼2:3 ratio to nitrogen and a ∼2:7 ratio to sulfur. The +I oxidation state of the copper species was confirmed by the edge position in the X-ray absorption near-edge structure (XANES) region of the X-ray absorption spectrum. These results show that upon immobilization of Cu-tmpa-O(CH2)4SH, the resulting structure is not identical to the homogeneous CuII-tmpa complex. Upon anchoring, a novel CuI species is formed instead. This illustrates the importance of a thorough characterization of heterogenized molecular systems before drawing any conclusions regarding the structure–function relationships.

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Section: Results and Discussionsupporting

confidence: 73%

“…A final comparison with the XANES data of a reference spectrum of Cu 2 O shows a significant negative shift of the onset energy of the absorption edge as well, confirming that the anchored Cu I species of interest is a molecular architecture rather than cuprous oxide (Figure S9 dotted green line). 48…”

Section: Results and Discussionmentioning

confidence: 99%

Elucidation of the Structure of a Thiol Functionalized Cu-tmpa Complex Anchored to Gold via a Self-Assembled Monolayer

Smits

Boer

et al. 2019

Inorg. Chem.

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“…Studies have shown that NPs sorbed by bacterial cells generally induce more toxic effects, acting as a local point source or through direct physical interactions (Li et al ., ). CeO 2 , zinc oxide, cupric oxide (CuO) and TiO 2 NPs are commonly used by industry (Kasemets et al ., ; Gomes et al ., ). The following examples demonstrate how STXM at metal 2p, metal 3d and C 1s absorption edges may be used to monitor the interaction of the NP with river biofilms.…”

Section: Resultsmentioning

confidence: 97%

Soft X‐ray spectromicroscopy for speciation, quantitation and nano‐eco‐toxicology of nanomaterials

Lawrence

Swerhone

Dynes

et al. 2014

Journal of Microscopy

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There is a critical need for methods that provide simultaneous detection, identification, quantitation and visualization of nanomaterials at their interface with biological and environmental systems. The approach should allow speciation as well as elemental analysis. Using the intrinsic X-ray absorption properties, soft X-ray scanning transmission X-ray spectromicroscopy (STXM) allows characterization and imaging of a broad range of nanomaterials, including metals, oxides and organic materials, and at the same time is able to provide detailed mapping of biological components. Thus, STXM offers considerable potential for application to research on nanomaterials in biology and the environment. The potential and limitations of STXM in this context are discussed using a range of examples, focusing on the interaction of nanomaterials with microbial cells, biofilms and extracellular polymers. The studies outlined include speciation and mapping of metal-containing nanomaterials (Ti, Ni, Cu) and carbon-based nanomaterials (multiwalled carbon nanotubes, C60 fullerene). The benefits of X-ray fluorescence detection in soft X-ray STXM are illustrated with a study of low levels of Ni in a natural river biofilm.

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“…Gomes et. al . have also reported in‐situ XAS of Cu nanoparticles formation in microemulsion in well‐sealed containers.…”

Section: Introductionmentioning

confidence: 98%

In Situ XAS Study on Growth of PVP‐Stabilized Cu Nanoparticles

et al. 2018

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Cu nanoparticles have been synthesized from copper acetate using NaBH4 as a reducing agent and poly(N‐vinyl‐2‐pyrrolidone) (PVP) as a stabilizing agent under an inert ambience. In‐situ time‐resolved X‐ray absorption spectroscopy (XAS) measurement, which include both X‐ray near edge structure (XANES) and extended X‐ray absorption fine structure (EXAFS) techniques, have been carried out in a specially designed measurement cell during the formation of Cu nanoparticles using a specialized computer controlled flow setup. Principal Component Analysis (PCA) and Multivariate Curve Resolution with Alternating Least Squares (MCR‐ALS) analysis have been successfully applied to the time‐resolved Cu K‐edge XANES data recorded during the growth of Cu nanoparticles. PCA of the XANES spectra predicted three chemical species present in the reaction solution including an intermediate species apart from the initial and the product species. From MCR‐ALS analysis of the Cu K‐edge XANES spectra, the oxidation state of the reaction intermediate species and the concentration profile of the constituents during the reactions have been determined. Finally the EXAFS spectra of the intermediate species has been extracted and analyzed to predict the local structure of Cu cations in this species.

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An in situ X-ray absorption spectroscopy study of copper nanoparticles in microemulsion

Cited by 14 publications

References 28 publications

Elucidation of the Structure of a Thiol Functionalized Cu-tmpa Complex Anchored to Gold via a Self-Assembled Monolayer

Elucidation of the Structure of a Thiol Functionalized Cu-tmpa Complex Anchored to Gold via a Self-Assembled Monolayer

Soft X‐ray spectromicroscopy for speciation, quantitation and nano‐eco‐toxicology of nanomaterials

In Situ XAS Study on Growth of PVP‐Stabilized Cu Nanoparticles

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