Pingping Song

Facile construction of ultrafine nickel-zinc oxyphosphide nanosheets as high-performance electrocatalysts for oxygen evolution reaction

Realizing the synthesis of highly efficient electrocatalysts for water splitting is generally regarded as a significant section in the field of renewable energy conversion and storage but still an intriguing challenge. Here, a series of transition metal oxyphosphides with ultrafine nanosheet structure have been successfully created as high-performance electrocatalysts for oxygen evolution reaction (OER). Taking advantages of the abundant surface defects, modified electronic effects, as well as the high surface active areas, we herein successfully construct a novel class of highly-efficient electrocatalysts, and the resultant NiZn oxyphosphide nanosheets (NiZnP NSs) can exhibit relatively low overpotentials of 290 and 332u202fmV to achieve the current densities of 10 and 50u202fmAu202fcm-2 for OER, respectively, outperforming most of non-noble metal electrocatalysts. More impressively, such NiZnP NSs can also retain high catalytic activity with negligible composition and structure variations after long-term electrochemical test. This work provides prospects to construct highly efficient, earth abundant, and ultra-durable two-dimensional (2D) electrocatalysts for water splitting.

Pt Islands on 3 D Nut-like PtAg Nanocrystals for Efficient Formic Acid Oxidation Electrocatalysis

Precise control of structures offers a great opportunity to efficiently tune the catalytic performance of nanomaterials, enhacing both their activity and durability. Herein, we achieve a new class of Pt islands on 3u2009D nut-like PtAg nanocrystals by exploiting the lower electronegativity of Ag in conjunction with the galvanic replacement of catalytically active Pt to Ag. Such nanostructures coated with Pt nanoparticles, exhibiting exposed facets, and active surface composition enhance formic acid oxidation electrocatalysis with optimized PtAg1 nut-like catalysts and achieved a factor of 4.0 and 2.4 in mass and specific activities (1728.3u2005mAu2009mg-1 and 3.31u2005mAu2009cm-2 ) relative to those of the commercial Pt/C (431.2u2005mAu2009mg-1 and 1.41u2005mAu2009cm-2 ), respectively. Moreover, such 3u2009D PtAg1 nut-like catalysts also display great enhancement in durability with less decay for at last 500u2005cycles, showing a great potential to serve as promising catalysts for fuel cells and other applications. Our work provides a fundamental insight on the effect of the morphology toward liquid fuel electrooxidation, which may pave a new way for the fabrication of highly efficient electrocatalysts for fuel cells.

Sophisticated Construction of Binary PdPb Alloy Nanocubes as Robust Electrocatalysts toward Ethylene Glycol and Glycerol Oxidation

The design of nanocatalysts by controlling pore size and particle characteristics is crucial to enhance the selectivity and activity of the catalysts. Thus, we have successfully demonstrated the synthesis of binary PdPb alloy nanocubes (PdPb NCs) by controlling pore size and particle characteristics. In addition, the as-obtained binary PdPb NCs exhibited superior electrocatalytic activity of 4.06 A mg-1 and 16.8 mA cm-2 toward ethylene glycol oxidation reaction and 2.22 A mg-1 and 9.2 mA cm-2 toward glycerol oxidation reaction when compared to the commercial Pd/C. These astonishing characteristics are attributed to the attractive nanocube structures as well as the large number of exposed active areas. Furthermore, the bifunctional effects originated from Pd and Pb interactions help to display high endurance with less activity decay after 500 cycles, showing a great potential in fuel cell applications.

Ethylene Glycol Electrooxidation Based on Pentangle-Like PtCu Nanocatalysts

The research of active and stable electrocatalysts toward liquid-fuel oxidation reaction is of great significance for the large-scale commercialization of fuel cells. Although extensive efforts have been devoted to pursuing high-performance nanocatalysts for fuel cells, both the high cost and sluggish reaction kinetics have been two major drawbacks that limited its commercial development. In this regard, we demonstrated a facile solvothermal method for the syntheses of an advanced class of PtCu nanocatalysts with a unique pentangle-like shape. By combining the merits of a highly active surface area as well as the synergistic and electronic effects, the as-prepared pentangle-like Pt3 Cu nanocatalysts showed superior electrocatalytic activity towards ethylene glycol oxidation with a mass and specific activities of 5162.6u2005mAu2009mg-1 and 9.7u2005mAu2009cm-2 , approximately 5.0 and 5.1u2005times higher than the commercial Pt/C, respectively. More significantly, the Pt3 Cu pentangle also showed excellent long-term stability with less activity decay and negligible changes in structure after 500u2005cycles, indicating another class of anode catalysts for fuel cells and beyond.

Shape-Controlled Synthesis of Platinum–Copper Nanocrystals for Efficient Liquid Fuel Electrocatalysis

Well-defined noble metal nanomaterials are attractive as catalysts for various applications because of abundant surface-active sites. However, the shape-controlled synthesis of high-performance Pt-based nanocatalysts remains a forbidden challenge. We herein demonstrate a versatile approach for realizing the systemically controlled syntheses of bimetallic Pt-Cu nanocrystals (NCs) from concave nanocubes (CNCs), to excavated nanocubes, to tripods via simply switching the amount of glycine (reducing agent). These Pt-Cu nanostructures supply a desirable platform for carrying out the structure-dependent electrocatalytic studies in the liquid fuel electro-oxidation. Impressively, all of the Pt-Cu NCs show high activity and outstanding durability for alcohol oxidation. In particular, the Pt-Cu CNCs display unprecedent high activity toward MOR and EOR, which are found to be 2041.1 and 5760.9 mA mg-1 in mass activity, 7.9- and 11.5-folds greater than the commercial Pt/C catalysts, respectively, showing a promising class of electrocatalysts for fuel cells. This work sheds great promise for optimizing the electrochemical catalysis by precisely modulating the structure of catalysts.

Particle size effects of PtAg nanoparticles on the catalytic electrooxidation of liquid fuels

A tailored design of highly efficient Pt-based bimetallic nanocatalysts for the electrooxidation of liquid fuel offers a promising approach for the commercialization of fuel cells. Although extensive researches on seeking high-performance Pt-based nanocrystals for electrocatalytic reactions have been conducted, the particle size effects of bimetallic Pt-based nanoparticles (NPs) on the fuel cell reaction remain unclear. In this regard, we herein report a size-controlled synthesis of bimetallic Pt–Ag NPs. By varying the amount of phloroglucinol involved in the reaction, Pt–Ag NPs with variable sizes from 7.5 to 15.0 nm can be prepared. By virtue of the unique particle size effects, abundant active sites on the surface as well as the synergistic and electronic effects due to Pt and Ag, these Pt–Ag NPs with the smallest particle size exhibit the best electrocatalytic activities for ethylene glycol and glycol oxidation reactions, and the electrocatalytic activities of Pt–Ag NPs are as much as 3.1 and 3.4 times higher when compared with those of the commercial Pt/C catalysts. This research can provide significant guidelines for the size selection of bimetallic Pt-based nanocatalysts with both enhanced activity and durability for fuel cell reactions.

High-Quality Platinum-Iron Nanodendrites with a Multibranched Architecture as Efficient Electrocatalysts for the Ethanol Oxidation Reaction

Although great success has been made in the design of well‐defined nanocrystals (NCs) with various morphologies, a facile method to prepare desirable NCs with large active surface areas and unique facets remains an arduous challenge. Herein, we demonstrate a facile method for the successful synthesis of high‐quality PtFe nanodendrites with a multibranched architecture; these nanodendrites have an abundance of exposed surface active sites that are available for ethanol molecules. Detailed study of its electrocatalytic properties revealed that the resultant superbranched PtFe nanocatalysts displayed superior electrocatalytic activity towards ethanol oxidation with unprecedentedly high mass/specific activities of 3692.5u2005mAu2009mg−1 and 7.02u2005mAu2009cm−2; these values are 9.3 and 10.0‐fold higher than those of a commercial Pt/C catalyst, signifying that the these nanodendrites may serve as highly efficient catalysts for fuel cells and beyond.