Li-Li He

A facile general strategy for synthesis of palladium-based bimetallic alloyed nanodendrites with enhanced electrocatalytic performance for methanol and ethylene glycol oxidation

In this work, a facile general strategy is developed for preparation of palladium-based bimetallic alloyed nanodendrites (PdM NDs, M = Pt, Co, and Ni) via coreduction of Pd(II) acetylacetonate and M(II/III) acetylacetonate salts with oleylamine. Hexadecylpyridinium chloride monohydrate (HDPC) is used as a co-surfactant for preventing the aggregation of nanodendrites. Control experiments varying the precursors and reaction time demonstrate that the dendritic nanocrystals are formed via aggregation-based crystal growth. The as-prepared hybrid nanocrystals display improved electrocatalytic activity and better stability for methanol and ethylene glycol (EG) oxidation, compared with home-made Pd NDs and commercial Pd black catalysts. The developed method provides a novel platform for synthesis of novel electrocatalysts in fuel cells.

A general strategy for the facile synthesis of AuM (M = Pt/Pd) alloyed flowerlike-assembly nanochains for enhanced oxygen reduction reaction

In this work, a general strategy was developed for the facile synthesis of bimetallic AuM (M = Pt or Pd) alloyed flowerlike-assembly nanochains (FANs) with the assistance of diprophylline as a structure-directing and stabilizing agent. The morphologies, crystal structures, and compositions of AuPt and AuPd FANs were investigated primarily by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The formation mechanism was discussed in some detail by varying the concentration of diprophylline. The as-prepared AuM FANs displayed improved catalytic activities and better stabilities for oxygen reduction reaction (ORR) compared to commercial E-TEK Pt/C, Pt black and Pd black.

Surfactant-free synthesis of reduced graphene oxide supported porous PtAu alloyed nanoflowers with improved catalytic activity

A simple and facile one-pot wet-chemical co-reduction method was developed for the synthesis of reduced graphene oxide supported porous PtAu alloyed nanoflowers (PtAu-nanoflowers/rGO). p-Aminopyridine was employed as a structure-directing agent and a stabilizing agent. No seed, template, surfactant, or polymer was involved in the synthesis process. It was found that the reaction temperature and the dosage of p-aminopyridine were essential for the final product. Furthermore, the as-prepared nanocomposites showed improved catalytic activity for the reduction of 4-nitrophenol in contrast to monometallic Pt nanocrystals/rGO, Au nanocrystals/rGO, and commercial Pt/C (50 wt%).

Facile large-scale synthesis of Au–Pt alloyed nanowire networks as efficient electrocatalysts for methanol oxidation and oxygen reduction reactions

In this work, bimetallic Au–Pt alloyed nanowire networks (AuPt NNs) were facilely synthesized by a simple and rapid one-pot wet-chemical method on a large-scale, using N-methylimidazole as a structure-directing agent and a weak stabilizing agent. The surface of AuPt NNs was clean owing to the easy removal of the adsorbed N-methylimidazole. The control experiments demonstrated that the morphologies of AuPt NNs were strongly correlated with the amount of N-methylimidazole and reaction temperature. The formation mechanism included the four-stage growth processes: rapid nucleation, selective adsorption, π–π induced assembly, and oriented attachment growth. The as-synthesized AuPt NNs exhibited enhanced electrocatalytic activity and improved stability for methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) as compared to commercial Pt black and individual Pt nanoparticles.