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

DOI: 10.1039/C9NA00159J

Authors: George F. Tierney (University of Southampton; UK Catalysis Hub, Research Complex at Harwell) , Donato Decarolis (University of Southampton; UK Catalysis Hub, Research Complex at Harwell) , Norli Abdullah (UK Catalysis Hub, Research Complex at Harwell; National Defense University of Malaysia; University College London) , Scott M. Rogers (University College London (UCL)) , Shusaku Hayama (Diamond Light Source) , Martha Briceno De Gutierrez (Johnson Matthey Technology Centre) , Alberto Villa (Universitá degli Studi di Milano) , C. Richard A. Catlow (UK Catalysis Hub, Research Complex at Harwell; University College London; Cardiff University) , Paul Collier (Johnson Matthey Technology Centre) , Nikolaos Dimitratos (Alma Mater Studiorum Università di Bologna) , Peter Wells (University of Southampton; UK Catalysis Hub, Research Complex at Harwell; Diamond Light Source)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Nanoscale Advances , VOL 4

State: Published (Approved)
Published: May 2019
Diamond Proposal Number(s): 17283

Abstract: Sol-immobilization is increasingly used to achieve supported metal nanoparticles (NPs) with controllable size and shape; it affords a high degree of control of the metal particle size and yields a narrow particle size distribution. Using state-of-the-art beamlines, we demonstrate how X-ray absorption fine structure (XAFS) techniques are now able to provide accurate structural information on nano-sized colloidal Au solutions at μM concentrations. This study demonstrates: (i) the size of Au colloids can be accurately tuned by adjusting the temperature of reduction, (ii) Au concentration, from 50 μM to 1000 μM, has little influence on the average size of colloidal Au NPs in solution and (iii) the immobilization step is responsible for significant growth in Au particle size, which is further exacerbated at increased Au concentrations. The work presented demonstrates that an increased understanding of the primary steps in sol-immobilization allows improved optimization of materials for catalytic applications.

Subject Areas: Materials, Chemistry


Instruments: I20-Scanning-X-ray spectroscopy (XAS/XES)

Added On: 28/05/2019 15:55

Documents:
jj555.pdf

Discipline Tags:

Physical Chemistry Catalysis Chemistry Materials Science Nanoscience/Nanotechnology

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS)