Silver and palladium nanoparticles produced using a plant extract as reducing agent, stabilized with an ionic liquid: sizing by X-ray powder diffraction and dynamic light scattering

Abstract

Powder X-ray diffraction and dynamic light scattering (DLS) sizing of silver (Ag) and palladium (Pd) nanoparticles produced within aqueous plant extract and the effect of introducing of an ionic liquid are reported in this paper. The simple and novel synthesis of silver and palladium nanoparticles using the reducing power of Persea americana (Pa) bark extract is reported and the effect of adding 1-ethyl-3-methylimidazolium tosylate [EMIm][Tos] is described. Detailed powder X-ray interpretation allowed determination of the crystalline grain sizes of 16 ± 4 nm for Ag–Pa, 13 ± 2 nm for Ag–Pa[EMIm][Tos], 16 ± 3 nm for Pd–Pa and 9 ± 1 nm for Pd–Pa[EMIm][Tos] according to the Scherrer peak analysis. A size contraction occurs when moving from plant extract alone to plant extract/ionic liquid. These grain sizes are 9 nm for Ag–Pa and for 9 nm Ag–Pa[EMIm][Tos], 15 nm for Pd–Pa and 7 nm for Pd–Pa[EMIm][Tos] when the Williamson–Hall plot intercept is used. Modal hydrodynamic sizes were determined by DLS as 57 nm for Ag–Pa, 72 nm for Ag–Pa[EMIm][Tos], 390 nm for Pd–Pa and 98 nm for Pd–Pa[EMIm][Tos] providing indications on how the particles behave in solution. Intrinsic stresses of 0.177 GPa for Ag–Pa, 0.219 GPa for Ag–Pa[EMIm][Tos], 0.382 GPa for Pd–Pa and 0.190 GPa for Pd–Pa[EMIm][Tos] and dislocation densities of (6 ± 3) × 10−3 nm−2 for Ag–Pa, (9 ± 3) × 10−3 nm−2 for Ag–Pa[EMIm][Tos], (5 ± 2) × 10−3 nm−2 for Pd–Pa and (16 ± 4) × 10−3 nm−2 for Pd–Pa[EMIm][Tos] have been obtained. Keywords: Silver nanoparticles, Palladium nanoparticles, Persea americana bark, 1-Ethyl-3-methylimidazolium tosylate, Size contraction, Powder X-ray diffraction, Dynamic light scattering