2. Ex pe rime nt al
2.1. Synthesis of metallic nanoparticles by sonication
Ca rb on Vu lc a n wa s us ed as s up p or t of m et a ll ic n an op a rt ic le s. Al l
so n ic ati on ex pe rim en ts we re pe rf or m ed in a ni t rog e n a tmo s ph er e.
Th e re d uc ti on of m et al li c n an op a rt ic le s wa s f ol low ed ev er y h ou r
by UV – Vi s a bs orp ti on sp ect ra re co rd ed wi th a s pe c tr op h ot om et er
(Thermo Scientific).
2.1.1. Synthesis of monometallic Pt/C and Ag/C (10 wt.% metal)
Fort y mi llilit ers o f 0 .5 m M a lc oh ol s ol ut ion of h ex ac hl orop la ti n ic a ci d
(H
2
Pt Cl
6·6H
2
O) was sonicated for 5 h in an ultrasonic bath (42 kHz) at
room temperature. Nitrogen was used to purge the solution before and
during the irradiation. After that, carbon Vulcan (37 mg) was added to
th e p la ti n um s olu t ion an d so n ic a ti on wa s c on ti nu ed du ri n g 1 h . Th e
solvent was removed by evaporation in an oven at 100 °C for 5 h. The
same methodology was used for the synthesis of Ag/C, except that the
in it ia l s oni c a ti on ti me wa s 7 h . Ag NO
3
wa s th e pr e cu rs or of s il ve r.
Ca rb on Vu lc a n ( 21. 5 m g) wa s a dd ed to the si lv er s ol ut io n an d th e