Layer-controlled Pt-Ni porous nanobowls with enhanced electrocatalytic performance

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• 作者：Hongsheng Fan ; Ming Cheng ; Zhenlei Wang ; Rongming Wang
• 关键词：Pt ; Ni nanobowls ; facile synthesis ; sodium citrate ; poly(vinylpyrrolidone) (PVP) ; electrocatalysis
• 刊名：Nano Research
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：10
• 期：1
• 页码：187-198
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Nanotechnology; Materials Science, general; Atomic/Molecular Structure and Spectra; Condensed Matter Physics; Biotechnology; Biomedicine, general;
• 出版者：Tsinghua University Press
• ISSN：1998-0000
• 卷排序：10

文摘

Hollow and porous Pt-based nanomaterials are promising catalysts with applications in many sustainable energy technologies such as fuel cells. Economical and green synthetic routes are highly desirable. Here, we report a facile approach to prepare double- and single-layered Pt-Ni nanobowls (DLNBs and SLNBs) with porous shells. Microstructural analysis revealed that the shells were constructed of alloyed Pt-Ni nanocrystals and small amounts of Ni compounds. X-ray photoelectron spectra showed that their Pt 4f binding energies shifted in the negative direction compared to those of the commercial Pt/C catalyst. Furthermore, the DLNBs contained greater contents of oxidized Ni species than the SLNBs. The layer-controlled growth processes were confirmed by microscopy, and a formation mechanism was proposed based on the assistance of citrate and poly(vinylpyrrolidone) (PVP). For the methanol oxidation reaction, the DLNBs and SLNBs exhibited 2.9 and 2.5 times higher mass activities than that of the commercial Pt/C catalyst, respectively. The activity enhancements were attributed to electronic effects and a bifunctional mechanism. Chronoamperometry and prolonged cyclic voltammetry indicated that the Pt-Ni bowl-like structures had better electrochemical properties and structural stability than the commercial Pt/C catalyst, thus making the Pt-Ni nanobowls excellent electrocatalysts for use in direct methanol fuel cells.