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

Abstract

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 efficie...