Surfactant dependent evolution of Au-Pd alloy nanocrystals from trisoctahedron to excavated rhombic dodecahedron and multipod： a matter of crystal growth kinetics  

作　　者：Qiaoli Chen Guifen Du Yongdi Dong Zhenming Cao Zhaoxiong Xie Lansun Zheng 

机构地区：[1]State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China [2]Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China

出　　处：《Science Bulletin》2017年第20期1359-1364,共6页科学通报（英文版）

基　　金：supported by the National Basic Research Program of China (2015CB932301);the National Key Research and Development Program of China (2017YFA0206801);the National Natural Science Foundation of China (21333008, 21773190 and J1310024)

摘　　要：In wet chemical syntheses of noble metal nanocrystals,surfactants play crucial roles in regulating their morphology.To date,more attention has been paid to the effect of the surfactant on the surface energy of crystal facets,while less attention has been paid to its effect on the growth kinetics.In this paper,using the growth of Au-Pd alloy nanocrystals as an example,we demonstrate that different concentration of surfactant hexadecyltrimethyl ammonium chloride(CTAC)may cause the different packing density of CTA+bilayers on different sites(face,edge or vertex)of crystallite surface,which would change the crystal growth kinetics and result in preferential crystal growth along the edge or vertex of crystallites.The unique shape evolution from trisoctahedron to excavated rhombic dodecahedron and multipod structure for Au-Pd alloy nanocrystals was successfully achieved by simply adjusting the concentration of CTAC.These results help to understand the effect of surfactants on the shape evolution of nanocrystals and open up avenues to the rational synthesis of nanocrystals with the thermodynamically unfavorable morphologies.In wet chemical syntheses of noble metal nanocrystals, surfactants play crucial roles in regulating their morphology. To date, more attention has been paid to the effect of the surfactant on the surface energy of crystal facets, while less attention has been paid to its effect on the growth kinetics. In this paper, using the growth of Au-Pd alloy nanocrystals as an example, we demonstrate that different concentration of surfactant hexadecyltrimethyl ammonium chloride （CTAC） may cause the different packing density of CTA＋ bilayers on different sites （face, edge or vertex） of crystallite surface, which would change the crys- tal growth kinetics and result in preferential crystal growth along the edge or vertex of crystallites. The unique shape evolution from trisoctahedron to excavated rhombic dodecahedron and multipod structure for Au-Pd alloy nanocrystals was successfully achieved by simply adjusting the concentration of CTAC. These results help to understand the effect of surfactants on the shape evolution of nanocrystals and open up avenues to the rational synthesis of nanocrystals with the thermodynamically unfavorable morphologies.

关 键 词：Au-Pd alloy MORPHOLOGY Nanocrystal SURFACTANT 

分 类 号：O78[理学—晶体学]