A Simple Route to the Synthesis of Pt Nanobars and the Mechanistic Understanding of Symmetry Reduction

Ruhui Chen; Quynh N Nguyen; Ming Zhao; Zitao Chen; Miaofang Chi; Younan Xia

doi:10.1002/chem.202004104

A Simple Route to the Synthesis of Pt Nanobars and the Mechanistic Understanding of Symmetry Reduction

Chemistry. 2021 Feb 5;27(8):2760-2766. doi: 10.1002/chem.202004104. Epub 2020 Dec 23.

Authors

Ruhui Chen¹, Quynh N Nguyen², Ming Zhao¹, Zitao Chen^{3

4}, Miaofang Chi⁴, Younan Xia^{1

3}

Affiliations

¹ School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA.
² Department of Chemistry, Agnes Scott College, Decatur, Georgia, 30030, USA.
³ The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, 30332, USA.
⁴ Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA.

PMID: 33152800
DOI: 10.1002/chem.202004104

Abstract

Noble-metal nanocrystals with anisotropic shapes have received increasing interest owing to their unique properties. Here, a facile route to the preparation of Pt nanobars with aspect ratios tunable up to 2.1 was reported by simply reducing a Pt^IV precursor in N,N-dimethylformamide (DMF) at 160 °C in the presence of poly(vinyl pyrrolidone) (PVP). In addition to its commonly observed roles as a solvent and a reductant, DMF could also decompose to generate CO, a capping agent capable of selectively passivating Pt{100} facets to promote the formation of nanobars. The size and aspect ratio of the nanobars could be tuned by varying the amount of Pt^IV precursor involved in the synthesis, as well as the concentration of PVP because of its dual roles as a stabilizer and a co-reductant. Our mechanistic study indicated that the anisotropic growth resulted from both particle coalescence and localized oxidative etching followed by preferential growth.

Keywords: CO-mediated synthesis; Pt nanobars; localized oxidative etching; particle coalescence; symmetry breaking.

Abstract

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