Platinum Nanoparticles on Metalloid Antimony Functionalized Graphitic Nanoplatelets for Enhanced Water Electrolysis

Abstract

Platinum (Pt) nanoparticles are considered to be the most efficient catalyst for acidic hydrogen evolution reaction (HER). However, they are expensive and unstable, because of agglomeration and Ostwald ripening. It is critically necessary for developing a better catalytic support to stabilize the Pt nanoparticles at low loading amounts. One efficient route to improving both catalytic activity and durability is metal catalysts stably anchored on heteroatom functionalized carbon supports via their strong interactions. Nevertheless, the interactions between “metallic” catalysts and “nonmetallic” heteroatom functionalized carbon supports are still unsatisfactory. Here, “metalloid” antimony (Sb) functionalized graphitic nanoplatelets (SbGnP) are reported to stably anchor Pt nanoparticles. The resulting Pt@SbGnP catalyst shows a record high acidic HER performance, attributable to the unique nature of Sb functional groups on SbGnP. Unlike typical low-period nonmetallic heteroatoms on carbon supports, high-period metalloid Sb with various oxidation states of SbO_x provided strong binding sites to stably anchor Pt nanoparticles, suppressing particle aggregation, and thus sustaining catalytic activity and stability.