Effect of organic vapors and potential-dependent Raman scattering of 2,6-dimethylphenylisocyanide on platinum nanoaggregates.
Effect of organic vapors and potential-dependent Raman scattering of 2,6-dimethylphenylisocyanide on platinum nanoaggregates.
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DOI：
10.1039/c0cp01619e
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发表时间：
2011-03
期刊：
影响因子：
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通讯作者：
K. Kim;K. Kim;Jeong-Yong Choi;K. S. Shin
中科院分区：
文献类型：
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作者：
K. Kim;K. Kim;Jeong-Yong Choi;K. S. Shin
研究了2，6-二甲基苯基异氰（2，6-DMPI）在Pt纳米聚集体上的表面增强拉曼散射特性，并与Au纳米聚集体进行了比较.由于通过异氰化物基团的排他性吸附，NC拉伸带对测量条件非常敏感，尽管环相关带显示可忽略的峰位移。在室温条件下，NC在Pt上的伸缩振动峰位移（29 cm（-1））是在Au上的（61 cm（-1））的一半，表明异氰化物基团对Au的给电子能力大于对Pt的给电子能力.在电化学环境中，在Pt和Au上，NC伸缩峰的斜率分别为0.42和0.36 cm（-1）V（-1）。另一方面，在丙酮和氨的存在下，2，6-DMPI在Pt上的NC伸缩带分别红移多达15和41 cm（-1），对应于Pt纳米聚集体的表面电位分别从+0.2降低到-0.2和-0.8 V。然而，在Au纳米聚集体上，丙酮似乎将Au的表面电位从+0.2 V增加到+0.3 V，尽管氨将表面电位从+0.2 V降低到-0.4 V。丙酮在与Pt相互作用时必须充当电子供体，而在与Au相互作用时充当电子受体，与从头算量子力学计算一致。
The surface-enhanced Raman scattering characteristics of 2,6-dimethylphenylisocyanide (2,6-DMPI) on Pt nanoaggregates, in ambient and electrochemical environments and in the presence of organic vapors, were examined and compared with those on Au nanoaggregates. Due to the exclusive adsorption via the isocyanide group, the NC stretching band was very susceptible to the measurement conditions although the ring associated bands showed negligible peak shifts. In ambient conditions, the peak shift of the NC stretching vibration on Pt (29 cm(-1)) was one half of that on Au (61 cm(-1)), suggesting that the electron donation capability of the isocyanide group to Au was greater than that to Pt. In the electrochemical environment, the NC stretching peak varied linearly with slopes of ∼42 and ∼36 cm(-1) V(-1) on Pt and Au, respectively. On the other hand, the NC stretching bands of 2,6-DMPI on Pt red-shifted by as much as 15 and 41 cm(-1), in the presence of acetone and ammonia, respectively, corresponding to the lowering of the surface potential of Pt nanoaggregates from +0.2 to -0.2 and -0.8 V, respectively. On Au nanoaggregates, however, acetone appeared to increase the surface potential of Au from +0.2 to +0.3 V, although ammonia decreased the surface potential from +0.2 to -0.4 V. Acetone must then act as an electron donor when interacting with Pt while it serves as an electron acceptor when interacting with Au, in agreement with an ab initio quantum mechanical calculation.