Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants.Here,we developed a simple aqueous synthetic method...Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants.Here,we developed a simple aqueous synthetic method to prepare bimetallic PdAu nanoflowers catalysts for methanol oxidation reaction(MOR)in alkaline environment.Their composition can be directly tuned by changing the ratio between Pd and Au precursors.Compared with commercial Pd/C catalyst,all of the PdAu nanoflowers catalysts show the enhanced catalytic activity and durability.In particular,the PdAu nanoflowers specific activity reached 0.72 mA/cm^(2),which is 14 times that of commercial Pd/C catalyst.The superior MOR activity could be attributed to the unique porous structure and the shift of the d-band center of Pd.展开更多
The search for a novel strategy to sculpt semiconductor nanowires （NWs） at the atomistic scale is crucial for the development of new paradigms in optics, electronics, and spintronics. Thus far, the fabrication of si...The search for a novel strategy to sculpt semiconductor nanowires （NWs） at the atomistic scale is crucial for the development of new paradigms in optics, electronics, and spintronics. Thus far, the fabrication of single-crystalline kinked semiconductor NWs has been achieved mainly through the vapor-liquid-solid growth technique. In this study, we developed a new strategy for sculpting single-crystalline kinked wurtzite （WZ） MnSe NWs by triggering the nonpolar axial-oriented growth, thereby switching--at the atomistic scale---the NW growth orientation along the nonpolar axes in a facile solution-based procedure. This presents substantial challenges owing to the dominant polar c axis growth in the solution-based synthesis of one-dimensional WZ nanocrystals. More significantly, the ability to continuously switch the nonpolar axial-growth orientation allowed us to craft the kinking landscape of types 150°, 120°, 90°, and 60°. A probabilistic analysis of kinked MnSe NWs reveals the correlations of the synergy and interplay between these two sets of nonpolar axial growth-orientation switching, which determine the actual kinked motifs. Furthermore, discriminating the side-facet structures of the kinked NWs significantly strengthened the spatially selected interaction of Au nanoparticles. We envisage that such a facile solution-based strategy can be useful for synthesizing other single-crystalline kinked WZ-type transition-metal dichalcogenide NWs to develop novel functional materials with finely tuned properties.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.118740271 and 1774124)Technology Development Program of Jilin Province,China(Grant No.20180101285JC)the China Postdoctoral Science Foundation(Grant Nos.2019T120233 and 2017M621198)
文摘Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants.Here,we developed a simple aqueous synthetic method to prepare bimetallic PdAu nanoflowers catalysts for methanol oxidation reaction(MOR)in alkaline environment.Their composition can be directly tuned by changing the ratio between Pd and Au precursors.Compared with commercial Pd/C catalyst,all of the PdAu nanoflowers catalysts show the enhanced catalytic activity and durability.In particular,the PdAu nanoflowers specific activity reached 0.72 mA/cm^(2),which is 14 times that of commercial Pd/C catalyst.The superior MOR activity could be attributed to the unique porous structure and the shift of the d-band center of Pd.
基金This study is supported by the National Natural Sdence Foundation of China （Nos. 91227202, 21673100 and 11504126）, the RFDP （No. 20120061130006）, Changbai Mountain scholars program （No. 2013007）, Program for Innovative Research Team （in Science and Technology） in University of Jilin Province, the China Postdoctoral Science Foundation （No. 2014M561281）.
文摘The search for a novel strategy to sculpt semiconductor nanowires （NWs） at the atomistic scale is crucial for the development of new paradigms in optics, electronics, and spintronics. Thus far, the fabrication of single-crystalline kinked semiconductor NWs has been achieved mainly through the vapor-liquid-solid growth technique. In this study, we developed a new strategy for sculpting single-crystalline kinked wurtzite （WZ） MnSe NWs by triggering the nonpolar axial-oriented growth, thereby switching--at the atomistic scale---the NW growth orientation along the nonpolar axes in a facile solution-based procedure. This presents substantial challenges owing to the dominant polar c axis growth in the solution-based synthesis of one-dimensional WZ nanocrystals. More significantly, the ability to continuously switch the nonpolar axial-growth orientation allowed us to craft the kinking landscape of types 150°, 120°, 90°, and 60°. A probabilistic analysis of kinked MnSe NWs reveals the correlations of the synergy and interplay between these two sets of nonpolar axial growth-orientation switching, which determine the actual kinked motifs. Furthermore, discriminating the side-facet structures of the kinked NWs significantly strengthened the spatially selected interaction of Au nanoparticles. We envisage that such a facile solution-based strategy can be useful for synthesizing other single-crystalline kinked WZ-type transition-metal dichalcogenide NWs to develop novel functional materials with finely tuned properties.
