Title: The deposition of metal nanoparticles on carbon surfaces: the role of specific functional groups

Citation
Bowden B, Davies M, Davies PR, et al. (2018). The deposition of metal nanoparticles on carbon surfaces: the role of specific functional groups. Cardiff University. http://doi.org/10.17035/d.2018.0045183226


Access Rights: Data can be made freely available subject to attribution
Access Method: Click to email a request for this data to opendata@cardiff.ac.uk

Dataset Details
Publisher: Cardiff University
Date (year) of data becoming publicly available: 2018
Data format: .jpg, .png, vms
Software Required: CASAXPS (http://www.casaxps.com/) Version 2.3.1 +
WSxM ( http://www.wsxm.es/download.html, I. Horcas, R. Fernandez, J. Gomez-Rodriguez, J. Colchero, J. Gomez-Herrero and A. Baro, Rev. Sci. Instrum., 2007, 78, 013705.)

Estimated total storage size of dataset: Less than 1 gigabyte
DOI: 10.17035/d.2018.0045183226

Description
Data folders
Figure 1. AFM images showing the effect of different acid treatments on HOPG surfaces: (a) 0.25 M HNO3; (b) 0.5 M HNO3; (c) 5.0 M HNO3; (d) 2.0 M HCl; (e) Corresponding line profiles; (f) XP spectrum of (1s) region from image (b).
Figure 2: EXCEL chart of contact angle measurements of water on HCl treated HOPG surfaces before and after heating to 473 K.
Figure 3. XPS spectra of HOPG samples pre-treated with HCl at different concentrations and then, after drying, to a 2×10-6 M aqueous solution of HAuCl4. Curve fitting of the spectra is discussed above.
Figure 4: AFM images of HOPG surfaces treated with HCl and subsequently with a 2×10-6 M aqueous solution of HAuCl4. (a) After treatment with 1 M HCl; (b) 0.5 M HCl followed by 2×10-6 M HAuCl4; (c) 1.0 M HCl followed by 2×10-6 M HAuCl4; (d) 1.0 M HCl, heated to 373 K followed by 2×10-6 M HAuCl4;
Figure 5. XPS spectra showing the deposition of gold from a 2×10-6 M aqueous solution of HAuCl4 on HOPG surfaces pre-treated with HNO3 at different concentrations: (a) clean surface treated with gold solution; (b) 0.25 M HNO3; (c) 0.5 M HNO3; (d) 1.0 M HNO3; (e) 2.0 M HNO3; (f) 5.0 M HNO3. Curve fitting of the spectra is discussed above.
Figure 6: AFM images of HOPG surfaces treated with HNO3 and subsequently with a 2×10-6 M aqueous solution of HAuCl4. (a) After treatment with 2 M HNO3 followed by 2×10-6 M HAuCl4; (b) After treatment with 5 M HNO3 followed by 2×10-6 M HAuCl4;
Figure 7. XPS spectra showing the effect of aqua regia (AQR, 3HCl: 1HNO3) treatment on gold deposition from a 2×10-6 M aqueous solution of HAuCl4 on HOPG surfaces. (a) O(1s) spectrum showing the oxygen states generated on a clean surface by 5.0 M AQR treatment. Spectra (b)-(f) show gold deposition on the HOPG after treatment with AQR at increasing concentrations: (b) 0.25 M AQR; (c) 0.5 M AQR; (d) 1.0 M AQR; (e) 2.0 M AQR; (f) 5.0 M AQR.
Figure 8: AFM images of HOPG surfaces treated with aqua regia (AQR, 3HCl: 1HNO3) and subsequently with a 2×10-6 M aqueous solution of HAuCl4. (a) After treatment with 0.25 M AQR (b) After treatment with 1 M AQR followed by 2×10-6 M HAuCl4;
Figure 9. XPS spectra showing the effect of H2SO4 treatment of HOPG surfaces on gold deposition from a 2×10-6 M aqueous solution of HAuCl4. (a) After 0.1 M H2SO4; (b)-(f) show gold deposition on the HOPG after treatment with H2SO4 at increasing concentrations: (b) 0.1 M H2SO4; (c) 0.2 M H2SO4; (d) 0.3 M H2SO4.
Figure 10: AFM images of HOPG surfaces treated with H2SO4 and subsequently with a 2×10-6 M aqueous solution of HAuCl4. (a) After treatment with 0.1 M H2SO4; (b) 0.1 M H2SO4 followed by 2×10-6 M HAuCl4;
Figure 11. A comparison of curve fits of the O(1s) spectra from Figure 8. In (a) and (b) fits to the acid treated surface spectrum using two and three components respectively are compared. Whilst two components are sufficient to fit the overall envelope, three components, in which a peak at 532.7 eV can be assigned to OH(a), is also successful. The three peak fit is consistent with a model in which OH(a) reduces Au3+ to Au0.showing that both produce acceptable models. Spectra (c) to (d) show 3 peak fits for the remaining spectra in Figure 8.

Software required
•    All AFM data is
presented in the raw format created by Bruker Veeco Multimode system.
The AFM images can be read using WSxM software1 and contains information
about the experimental conditions.
•    All XPS data is presented in
standard VAMAS format with information contained about the experimental
conditions. CasaXPS v2.3.19 can be used to read the data amongst many
other suitable graphing software.2 Curve fits were made in CasaXPS using
a Gaussian-Lorentzian 30:70 mixed lineshape with spin orbit splitting
components for the Au(4f), S(2p) and Cl(2p) spectra fixed at 3.7, 1.16
and 1.6 eV, and relative areas of 4:3, 2:1 and 2:1 respectively.
•    The contact angle chart was plotted using EXCEL 2016
•    Diagrams were assembled using Inkscape3 and exported as jpg, png or tiff files

References
1    I. Horcas, R. Fernandez, J. Gomez-Rodriguez, J. Colchero, J. Gomez-Herrero and A. Baro, Rev. Sci. Instrum., 2007, 78, 013705.
2    N. Fairley, CasaXPS Manual: 2.3.15 Spectroscopy, Casa Software Ltd, 2009.
3    Draw Freely | Inkscape, https://inkscape.org/en/, (accessed 14 February 2018).

Research results based upon these data are published at http://doi.org/10.1039/C7FD00210F



Keywords

Gold catalysts, Surface science

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Last updated on 2018-19-04 at 11:07