Eur. Phys. J. B 65, 57-64 (2008)
https://doi.org/10.1140/epjb/e2008-00322-7

In situ SAXS study on size changes of platinum nanoparticles with temperature

¹ Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, & Graduate University of Chinese Academy of Sciences, Beijing 100049, P.R. China
² Jiangxi Institute of Measurement and Testing, Nanchang 330002, P.R. China

Corresponding author: ^a wuzh@mail.ihep.ac.cn

Received: 20 September 2007
Revised: 8 April 2008
Published online: 9 August 2008

Abstract

Poly(vinylpyrrolidone) (PVP)-coated platinum (Pt) nanoparticles were prepared in methanol-water reduction method. In situ small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) techniques were used to probe the size change of particles and crystallites with temperature. Tangent-by-tangent (TBT) method of SAXS data analysis was improved and used to get the particle size distribution (PSD) from SAXS intensity. Scherrer's equation was used to derive the crystallite size from XRD pattern. Combining SAXS and XRD results, a step-like characteristic of the Pt nanoparticle growth has been found. Three stages (diffusion, aggregation, and agglomeration) can be used to describe the growth of the Pt nanoparticles and nanocrystallites. Aggregation was found to be the main growth mode of the Pt nanoparticles during heating. The maximum growth rates of Pt nanoparticles and Pt nanocrystallites, as well as the maximum aggregation degree of Pt nanocrystallites were found, respectively, at 250 C, 350 °C and 300 °C. These results are helpful to understanding the growth mode of nanoparticles, as well as controlling the nanoparticle size.