RESUMO
Pt-based nanocomposites with low Pt utilization and high-activity by incorporating with other transition metals have received significant interest in catalysis. Meanwhile, loading Pt-based catalysts on graphene has great research value for improved stability and dispersity of the catalysts. Herein, a facile l-proline-mediated solvothermal strategy was reported to construct reduced graphene oxide (rGO) supported sheet-like PtCo nanocrystals (Pt78Co22 NCs/rGO) in ethylene glycol (EG). The as-synthesized nanocomposite manifested remarkably improved catalytic properties and chemical stability for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER), surpassing home-made Pt29Co71 nanoparticles (NPs)/rGO, Pt83Co17 NPs/rGO, Pt52Co48 NPs, commercial Pt/C and Pt black catalysts. These scenarios demonstrated an improved catalytic performances by tailoring the feeding ratio of Pt:Co and introducing rGO as a support. This work provides some new insights to design rGO-supported Pt-based catalysts by engineering the shapes and compositions in practical fuel cells.
RESUMO
Herein, highly branched Pt@Ag core-shell nanoparticles (Pt@Ag NPs) were fabricated by a facile one-pot wet-chemical approach, where poly(ethyleneimine) (PEI) served as structure-directing and capping agents. Their structure, morphology and composition were mainly characterized by a set of techniques. And their growth mechanism was discussed in some detail. The prepared catalyst exhibited remarkable enhancement in catalytic activity of 4-nitrophenol (4-NP) reduction as a proof-of-concept application, surpassing commercial Pt black and home-made Ag NPs catalysts. Also, the as-obtained catalyst showed superior stability without sacrificing the catalytic activity. These observations endow the catalyst possibility for practical applications in nitrophenols environmental remediation.
