Nanosponge Pt Modified Graphene Nanocomposites Using Silicon Monoxides as a Reducing Agent: High Efficient Electrocatalysts for Hydrogen Evolution

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.