Shape and size of silver
particles were determined using a scanning transmission electron
microscopy (STEM) in FE-SEM instrument in transmission
mode (FE-SEM, S-4800, Hitachi Co., Ltd., Matsuda, Japan). For Xray
diffraction (XRD) pattern, the samples were analyzed using an
X-ray diffractometer (PANalytical X
pert pro MRD diffractometer,
Amsterdam, Netherlands). The spectra were recorded using Cu K
radiation (wavelength of 1.54056Å) and a nickel monochromator
filtering wave at 40 kV and 30 mA with a scanning rate of 0.4◦/min
at room temperature.