Morphological characterization of the particles
Scanning electron microscopy (SEM) was conducted on a Hitachi
microscope (Hitachi S-4100) at an accelerating voltage of 10 kV and a working distance of 9e16 mm. Samples were sputter-coated
with a goldepalladium mixture under vacuum prior to examination.
Particle diameters were measured from the SEM micrographs
in their original magnification using the ImageJ software. Size
distributions were obtained from a minimum of 200
measurements.