In this letter, we report a quantitative analysis of how a Pt(II) precursor is reduced to atoms at different temperatures for the formation of Pt nanocrystals with different morphologies and sizes. Our results suggest that in the early stage of a synthesis, the Pt(II) precursor is reduced to atoms exclusively in the solution phase, followed by homogeneous nucleation to generate nuclei and then seeds. At a relatively low reaction temperature such as 22°C, the growth of the seeds is dominated by autocatalytic surface reduction that involves the adsorption and then reduction of the Pt(II) precursor on the surface of the just-formed seeds. This particular growth pathway results in relatively large assemblies of Pt nanocrystals. When the reaction temperature is increased to 100°C, the dominant reduction pathway will be switched from surface to solution phase, producing much smaller assemblies of Pt nanocrystals. Our results also demonstrate that a similar trend applies to the seed-mediated growth of Pt nanocrystals in the presence of Pd nanocubes.
Quantitative analysis of the reduction kinetics of a Pt(II) precursor in the context of Pt nanocrystal synthesis†
Shan Zhou, Tung-Han Yang, Ming Zhao, Younan Xia; Quantitative analysis of the reduction kinetics of a Pt(II) precursor in the context of Pt nanocrystal synthesis. Chin. J. Chem. Phys. 1 August 2018; 31 (4): 370–374. https://doi.org/10.1063/1674-0068/31/cjcp1805121
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