READ ME FILE For ‘Extracting Structural Information of Au Colloids at Ultra-Dilute Concentrations: Identification of Growth During Nanoparticle Immobilization’
Dataset DOI: 10.5258/SOTON/D0921
ReadMe Author: Peter Wells, University of Southampton https://orcid.org/0000-0002-0859-9172	
This dataset supports the publication:
George F. Tierney, Donato Decarolis, Norli Abdullah, Scott M. Rogers, Shusaku Hayama, Martha Briceno de Gutierrez, Alberto Villa, C. Richard A. Catlow, Paul Collier, Nikoloas Dimitratos, Peter P. Wells.
Extracting Structural Information of Au Colloids at Ultra-Dilute Concentrations: Identification of Growth During Nanoparticle Immobilization
Nanoscale Advances
DOI: https://doi.org/10.1039/C9NA00159J

This dataset contains:
Data supporting figures in the main text and ESI.
The figures are as follows:
Figure 2. (a-c) STEM HAADF of Au colloids prepared using increasing Au concentration at 1°C, (a) 50 µM (B) 100 µM (C) 1000 µM droppered onto a holey carbon TEM grid,(d-f) TEM images of the TiO2 supported colloidal Au, with immobilization performed at 1°C (d) 50 µM (e) 100 µM (f) 1000 µM.
Figure 3. XAFS taken at the Au L3-edge of the colloidal Au samples; (a&d) XANES spectra for the colloidal Au detailing change as a result of increasing synthesis temperature and Au concentration, (b&e) the normalised first derivative of the absorption for the temperature and Au concentration influenced colloids respectively and (c&f) experimental Fourier transform (FT) chi(k) data of the corresponding EXAFS signals for colloidal Au showing the influence of temperature and Au concentration.
Figure S1. UV-Vis spectra showing the formed Au SPR bands after reduction of the HAuCL4 precursor solutions prepared at: a) varied Au concentration and b) increasing temperature of reduction.
Figure S2. Acquired Au L3-edge XAFS data of an Au3+ reference (supplied by G. Malta1), spectra was measured on the B18 beamline, Diamond Light Source, Didcot, U.K.1 Also shown is the Au L3-edge XAFS data of a Au0 foil reference measured on I20 at the Diamond Light Source, Didcot, U.K. a) Shows comparison of the normalised first derivative of µ(E) for both the Au3+ (HAuCl4) and Au0 species. b) Full comparable XAFS spectra of both Au references, c) XANES spectra of both Au species, with noticable depletion of the white line peak for Au0 reference spectra. d) chi(k) space data for both Au3+  and Au0  reference compounds, e) shows the forward Fourier transform of the chi(k) data in S2D.
Figure S3. Acquired Au L3-edge XAFS data of colloid A1 (1°C and 100 µM [Au]) collected after leaving the colloid in the X-ray source beam path for a full scan (~ 48 minutes). The static colloid data is presented with references of the precursor salt (HAuCl4) and zero-valent Au, all data was acquired at the Diamond Light Source (DLS) , Didcot, U.K. Both A1 static colloid and Au reference datasets were acquired on the I20 scanning beamline of the DLS during the course of the experiment, and the HAuCl4 reference was supplied by G. Malta and acquired on the B18 beamline at the DLS.1 a) Comparison of the normalised first derivative of µ(E) for the references and static colloid, b) XANES spectra of Au references and static colloid, c) k-space data of A1 compared to both Au reference materials, d) shows the Fourier transform of the k data in S3c, detailing the nearest neighbouring atomic species to the absorbing atom.
Figure S4. EXAFS chi data taken at the Au L3-edge of both Au NP series; (a&b) colloidal Au NPs, (c&d) TiO2 supported Au NPs.
Figure S5. XAFS taken at the Au L3-edge of the TiO2 supported Au samples;  a) XANES spectra for the supported Au NPs detailing change as a result of increasing Au concentration.  b) The normalised first derivative of the absorption for Au concentration influenced supported NPs respectively, c) Experimental Fourier transform (FT) chi(k) data of the corresponding EXAFS signals for supported Au NPs showing the influence of Au concentration.
Figure S6. Fitted experimental Fourier transform k data of the corresponding EXAFS signals for colloidal Au NPs, synthesised using: a) an increase in the temperature of reduction and b) an increase in the concentration of Au present in the precursor solution.
Figure S7. Histograms showing the average Au NP sizes and standard deviations calculated from TEM images of 1 wt. %Au/TiO2  prepared with increasing Au concentration: a) 50, b) 100 and c) 1000 µM respectively.
Figure S8. TEM images of 1 wt. %Au/TiO2  prepared under increasing temperature of reduction: a) 25°C, b) 50°C and c) 75°C respectively.

Date of data collection: October 2017 – January 2019
Information about geographical location of data collection: University of Southampton, U.K.
Dataset available under a Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ licence
Projects: GCRF - START: Synchrotron Techniques for African Research and Technology
Publisher: University of Southampton, U.K. 
Date: May, 2019