Surface segregation of Au–Ag bimetallic nanowires
作者： Lanying Wei , Weihong Qi , Baiyun Huang , Mingpu Wang
DOI: 10.1016/J.COMMATSCI.2012.11.038
关键词: Particle 、 Selectivity 、 Chemical engineering 、 Tetragonal crystal system 、 Crystallography 、 Nanowire 、 Bimetallic strip 、 Nanoparticle 、 Mixing (process engineering) 、 Materials science 、 Truncated octahedron
摘要: Abstract Monte Carlo simulation has been performed to study the size, shape, composition and temperature dependent surface segregation behaviors atomic-scale structure of Au–Ag nanowires (NWs). Segregation Ag is observed in all NWs considered. The prism-like with tetragonal cross-section (T-NWs) enhanced by increasing particle sizes (or compositions) decreasing temperatures. For Au3Ag T-NWs, variation range fraction smaller than that truncated octahedron nanoparticles (TO-NPs) same diameter, however, AuAg AuAg3 T-NWs show opposite character. higher cylindrical (C-NWs) hexagonal (H-NWs) due T-NWs’ owning more low-coordination sites while C-NWs H-NWs are close each other under every composition, size temperature. It found most stable mixing configuration Ag-rich-surface, Au-rich-subsurface alloyed-core structures. Accordingly, calculated alloying extents for consistent those NPs. possible effects shape distribution Au atoms on tuning catalytic activity selectivity bimetallic also discussed.
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sci-hub.se 参考文章(24)
C. M. Chang, C. Cheng, C. M. Wei, CO oxidation on unsupported Au55, Ag55, and Au25Ag30 nanoclusters. Journal of Chemical Physics. ,vol. 128, pp. 124710- 124710 ,(2008) , 10.1063/1.2841364
D. Belić, R. L. Chantry, Z. Y. Li, S. A. Brown, Ag-Au nanoclusters: Structure and phase segregation Applied Physics Letters. ,vol. 99, pp. 171914- ,(2011) , 10.1063/1.3656244
Guillermo Bozzolo, Jorge E. Garcés, Gregory N. Derry, Atomistic modeling of segregation and bulk ordering in Ag–Au alloys Surface Science. ,vol. 601, pp. 2038- 2046 ,(2007) , 10.1016/J.SUSC.2007.02.035
Fabrizio Cleri, Vittorio Rosato, Tight-binding potentials for transition metals and alloys. Physical Review B. ,vol. 48, pp. 22- 33 ,(1993) , 10.1103/PHYSREVB.48.22
Fuyi Chen, Roy L. Johnston, Charge transfer driven surface segregation of gold atoms in 13-atom Au–Ag nanoalloys and its relevance to their structural, optical and electronic properties Acta Materialia. ,vol. 56, pp. 2374- 2380 ,(2008) , 10.1016/J.ACTAMAT.2008.01.048
S. Link, C. Burda, Z. L. Wang, M. A. El-Sayed, Electron dynamics in gold and gold–silver alloy nanoparticles: The influence of a nonequilibrium electron distribution and the size dependence of the electron–phonon relaxation Journal of Chemical Physics. ,vol. 111, pp. 1255- 1264 ,(1999) , 10.1063/1.479310
Reji Philip, G. Ravindra Kumar, N. Sandhyarani, T. Pradeep, Picosecond optical nonlinearity in monolayer-protected gold, silver, and gold-silver alloy nanoclusters Physical Review B. ,vol. 62, pp. 13160- 13166 ,(2000) , 10.1103/PHYSREVB.62.13160
J. R. Kitchin, J. K. Nørskov, M. A. Barteau, J. G. Chen, Role of strain and ligand effects in the modification of the electronic and chemical properties of bimetallic surfaces Physical Review Letters. ,vol. 93, pp. 156801- ,(2004) , 10.1103/PHYSREVLETT.93.156801
Z. Y. Li, J. P. Wilcoxon, F. Yin, Y. Chen, R. E. Palmer, R. L. Johnston, Structures and optical properties of 4–5 nm bimetallic AgAu nanoparticles Faraday Discussions. ,vol. 138, pp. 363- 373 ,(2008) , 10.1039/B708958A
B. C. Curley, G. Rossi, R. Ferrando, R. L. Johnston, Theoretical study of structure and segregation in 38-atom Ag-Au nanoalloys The European Physical Journal D. ,vol. 43, pp. 53- 56 ,(2007) , 10.1140/EPJD/E2007-00091-Y