Facile synthesis: Pt nanosponges, nanonetworks, and nanodendrites (see figure) are
synthesized through a unique galvanic replacement reaction between Te nanowires and
PtCl(6) (2-) ions in the presence of sodium dodecyl sulfate. The three Pt nanomaterials
all have large active surface areas and highly electrocatalytic activities for the
oxidation of methanol.In this paper, we report a simple approach for the preparation
of various porous Pt nanomaterials (NMs) in aqueous solution. Employing different
temperatures and concentrations of sodium dodecyl sulfate (SDS), we obtained Pt nanosponges,
Pt nanonetworks, and Pt nanodendrites from the reduction of PtCl(6) (2-) ions via
galvanic replacement reactions with Te nanowires (length: 879 nm; diameter: 19 nm).
At ambient temperature, Pt nanosponges and Pt nanodendrites formed selectively in
the presence of SDS at concentrations of <10 mM and>50 mM, respectively. At elevated
reaction temperatures, we obtained Pt nanonetworks and Pt nanodendrites in the presence
of SDS at concentrations of <10 mM and >50 mM, respectively. Transmission electron
microscopy images revealed that these Pt NMs were all composed of one dimensional
Pt nanostructures having widths of 3.0+/-1.0 nm and lengths of 17.0+/-4.8 nm. Cyclic
voltammetry data indicated that the as-prepared Pt nanonetworks, nanosponges, and
nanodendrites possessed large electrochemically active surface areas (77.0, 70.4,
and 41.4 m(2) g(-1), respectively). For the electrocatalytic oxidation of methanol,
the ratio of the forward oxidation peak current (I(f)) to the backward peak current
(I(b)) of the Pt nanodendrites, nanosponges, and nanonetworks were all high (I(f)/I(b)=2.88,
2.66, and 2.16, respectively). These three NMs exhibit greater electrocatalytic activities
and excellent tolerance toward poisoning species for the oxidation of methanol when
compared with the performance of standard Pt NMs.