Modulating
the morphology of Pt is an effective approach to augment
the active sites and mass activities for hydrogen evolution reaction
(HER). Here a facile one-step method is employed to fabricate Pt modified
graphene nanocomposites (Pt-G) with the help of silicon monoxides
(SiO) and hydrofluoric acid. SiO is introduced as a reducing agent
for Pt ions and graphene oxides through Si–H bonds and promotes
the catalytic performance of Pt-G. The obtained Pt on graphene shows
a nanosponge structure due to the secondary nucleation and in situ growth on the SiO. When the Pt-G nanocomposites
are employed as electrocatalysts for HER, the optimal catalyst shows
high mass activity (8.45 A·mg–1) as 1.6 and
1.9 times as those of commercial 20 wt % Pt/C and Pt-G-gly (obtained
by glycol reduction) at overpotential of 0.2 V. The current density
of the catalysts exceeds that of commercial 20 wt % Pt/C at high overpotentials
because SiO increases the desorption rate of hydrogen. Furthermore,
the residual SiO could efficiently avoid the aggregation of Pt and
restacking of the graphene, which increase the stability of the catalysts.