Structure of water at the electrified platinum-water interface:: A study by surface-enhanced infrared absorption spectroscopy
Structure of water at the electrified platinum-water interface:: A study by surface-enhanced infrared absorption spectroscopy
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DOI：
10.1021/jp710386g
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发表时间：
2008-03-20
影响因子：
3.7
通讯作者：
Yamakata, Akira
中科院分区：
文献类型：
--
作者：
Osawa, Masatoshi;Tsushima, Minoru;Yamakata, Akira
用衰减全反射模式下的表面增强红外吸收光谱研究了在H2SO4和HClO4中多晶Pt电极上水的结构与外加电位的关系。在记录光谱时，以被CO覆盖的电极表面作为参考，可以得到与表面接触的界面水层（单层或双层）的绝对红外光谱，而不受大量水的干扰。界面水的光谱与本体水的光谱有很大的不同，并在电极的零电荷电位周围发生变化。光谱变化归因于水分子的电位依赖重定向，从带负电荷表面的弱氢键合氧取向到带正电荷表面的强氢键近平取向，这与文献中报道的理论模拟一致。明确的实验证据表明，在带正电的表面上形成了稳定的冰状结构水。
Surface-enhanced infrared absorption spectroscopy in the attenuated total reflection mode is used to examine the structure of water on a polycrystalline Pt electrode in H2SO4 and HClO4 as a function of applied potential. The electrode surface covered with CO is used as the reference in recording spectra, which enables us to obtain the absolute infrared spectrum of the interfacial water layer (monolayer or bilayer) in contact with the surface with negligible interference from the bulk water. The spectrum of the interfacial water is largely different from that of bulk water and changes around the potential of zero charge of the electrode. The spectral changes are ascribed to the potential-dependent reorientation of water molecules from a weakly hydrogen-bonded oxygen-up orientation at the negatively charged surface to a strongly hydrogen-bonded nearly flat orientation at the positively charged surface in agreement with theoretical simulations reported in the literature. Clear experimental evidence of the formation of a stable ice-like structured water on the positively charged surface is reported.