Eur. Phys. J. D 42, 93-101 (2007)
https://doi.org/10.1140/epjd/e2007-00015-y

Copper and copper oxide nanoparticles in a cellulose support studied using anomalous small-angle X-ray scattering

¹ Division of X-ray Physics, Department of Physical Sciences, P.O. Box 64, University of Helsinki, 00014 Helsinki, Finland
² Institut für Festkörperforschung, Forschungszentrum Jülich, Postfach 1913, 52425 Jülich, Germany
³ Institute of Macromolecular Compounds, Russian Academy of Sciences, Bolshoy pr. 31, St. Petersburg, 199004, Russia

Corresponding author: ^a ritva.serimaa@helsinki.fi

Received: 26 September 2006
Revised: 1 December 2006
Published online: 31 January 2007

Abstract

Microcrystalline cellulose is a porous natural material which can be used both as a support for nanoparticles and as a reducer of metal ions. Cellulose supported nanoparticles can act as catalysts in many reactions. Cu, CuO, and Cu₂O particles were prepared in microcrystalline cellulose by adding a solution of copper salt to the insoluble cellulose matrix and by reducing the copper ions with several reducers. The porous nanocomposites were studied using anomalous small angle X-ray scattering (ASAXS), X-ray absorption spectroscopy, and X-ray diffraction. Reduction of Cu²⁺ with cellulose in ammonium hydrate medium yielded crystalline CuO nanoparticles and the crystallite size was about 6–20 nm irrespective of the copper concentration. The size distribution of the CuO particles was determined with ASAXS measurements and coincided with the crystallite sizes. Using sodium borohydrate or hydrazine sulfate as a reducer both metallic Cu and Cu₂O nanoparticles were obtained and the crystallite size and the oxidation state depended on the amount of reducer.