Extracting structural information of Au colloids at ultra-dilute concentrations: identification of growth during nanoparticle immobilization

Abstract

This paper describes the structural characterization of ultra-dilute colloidal Au nanoparticle solutions using X-ray absorption spectroscopy (XAS) and the particle growth during immobilization.

Controlling the Production of Acid Catalyzed Products of Furfural Hydrogenation by Pd/TiO2

“…All powdered catalysts were characterised using transmission electron microscopy (TEM), with their average NP sizes and particle size distributions/dispersions evaluated using ImageJ software (Figures S5, S6) [39] . An initial comparison of catalysts PdWPA and PdWP, shows that an acidified immobilization step increases the average NP size (PdWP=1.7 nm, PdWPA=2.6 nm), agreeing with our previous work in this area [10] . However, it is important to note there is a stark decrease in Pd loading for PdWP (0.25 wt %).…”

“…In general terms, the synthetic process can be divided into four stages: (i) chemical reduction of the precursor metal salt (e. g. Na 2 [PdCl 4 ]), (ii) capping of the formed colloids using a stabilizer (e. g. poly‐vinyl alcohol (PVA)), (iii) immobilization of the colloidal, and (iv) filtration, washing and drying of the catalyst slurry. The systematic studies to date have focussed on the choice of reducing agent, [2,7] synthesis temperature, [8,9] precursor concentration, [10,11] and the nature of the stabilizing agent employed (electrostatic, steric stabiliser) [12–15] …”

Identification of the key steps in the self-assembly of homogeneous gold metal nanoparticles produced using inverse micelles

“…In situ X-ray Absorption Fine Structure (XAFS) is a powerful method to follow the changes in the electronic structure of metals during the reduction process. 27,28 In particular, XANES is used to observe changes in oxidation state of the Au species, whereas Extended X-ray Absorption Fine Structure (EXAFS) technique can monitor the formation of Au clusters through detection of the Au-Au scattering pair evolution. 10,27 Whereas XAFS reveals information on the local environment of the gold atoms (i.e.…”