Jie-Ning Zheng

Facile synthesis of Pt–Pd nanodendrites and their superior electrocatalytic activity

In this report, well-dispersed porous Pt–Pd nanodendrites (Pt–Pd NDs) were synthesized at high yield by a simple, one-pot, wet chemical method without using any seed, template, or toxic organic solvent. Poly(vinylpyrrolidone) (PVP) and urea were employed as the co-stabilizing and co-structure-directing agents. It was found that the reaction temperature, the amount of PVP and urea, the Pt/Pd molar ratio, and the pH value of the reaction media greatly affected the size and shape of the Pt–Pd product. The as-prepared Pt–Pd nanocrystals had a larger active surface area, superior catalytic activity, and better stability for the electrooxidation of methanol and ethylene glycol (EG), compared with the commercial Pt-black and Pd-black catalysts.

One-pot synthesis of reduced graphene oxide supported hollow Ag@Pt core–shell nanospheres with enhanced electrocatalytic activity for ethylene glycol oxidation

In this study, a simple, facile and one-pot solvothermal method was developed for preparation of reduced graphene oxide (RGO) supported hollow Ag@Pt core–shell nanospheres (hAg@Pt), using ethylene glycol (EG) as a reducing agent and sodium dodecyl sulfate (SDS) as a soft template. Control experiments demonstrated that the molar ratios of the Pt–Ag precursors, the amount of SDS, the presence of RGO, and the reaction temperature were critical to the final nanocomposites. The as-prepared hAg@Pt–RGO showed the improved electrocatalytic activity and durability toward ethylene glycol oxidation, which can serve as a promising potential electrocatalyst in direct alcohol fuel cells.

Facile synthesis of hierarchical dendritic PtPd nanogarlands supported on reduced graphene oxide with enhanced electrocatalytic properties

A simple and facile method is developed for one-pot preparation of hierarchical dendritic PtPd nanogarlands supported on reduced graphene oxide (PtPd/RGO) at room temperature, without using any seed, organic solvent, or complex apparatus. It is found that octylphenoxypolyethoxyethanol (NP-40) as a soft template and its amount are critical to the formation of PtPd garlands. The as-prepared nanocomposites are further applied to methanol and ethanol oxidation with significantly enhanced electrocatalytic activity and better stability in alkaline media.

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.

Green synthesis of porous flower-like palladium with high electrocatalytic activity towards methanol oxidation

Using a Goods buffers, N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid (HEPES) both as reducing and shape-directing agent, porous Pd nanoflowers were facilely prepared with high-yield by one-pot chemical reduction method, which are preferentially growing along the (111) directions, without any seed or surfactant. It is found that the amount of the precursors, temperature and reaction time play important roles in this synthetic procedure. And the flower-like Pd nanostructures exhibit excellent electrocatalytic activity towards methanol oxidation in alkaline media with good stability, which show potential applications as an effective catalyst in direct methanol fuel cell.