Department of Chemistry, Pontifical Catholic University of Puerto Rico, Ponce, Puerto Rico.
J Am Chem Soc. 2010 Feb 24;132(7):2233-42. doi: 10.1021/ja909082s.
This manuscript compares the electrochemically controlled adsorption of hydroquinone-derived adlayers and their reductive desorption from nanometer-sized Pt(111) domains present on the surface (i) of model stepped single-crystal electrodes and (ii) of preferentially oriented Pt nanoparticles. The results obtained using a stepped surface series, i.e., Pt(S)[(n - 1)(111)x(110)], suggest that in the presence of 2 mM H(2)Q((aq)) the electrochemically detected desorption-adsorption process takes place selectively from ordered Pt(111) domains present as terraces, while being precluded at other available surface sites, i.e., Pt(110) steps, where adsorption takes place irreversibly. This domain-selective electroanalytical detection scheme is employed later to selectively monitor desorption-adsorption of hydroquinone-derived adlayers from ordered, nanometer-scaled Pt(111) domains on the surface of preferentially oriented Pt nanoparticles, confirming the existence of well-ordered (111) domains on the surface of the Pt nanoparticles. A good correlation is noted between the electrochemical behavior at well-ordered Pt(hkl) surfaces and at preferentially oriented Pt nanoparticles. Key learnings and potential applications are discussed. The results demonstrate the technical feasibility of performing domain-selective decapping of nanoparticles by handle of an externally controlled parameter, i.e., the applied potential.
本文比较了在模型阶梯单晶电极表面（i）和优先取向的 Pt 纳米粒子表面（ii）上存在的纳米级 Pt(111) 域上，电化学控制的对苯二酚衍生的吸附层的吸附及其还原解吸。使用阶梯表面系列，即 Pt(S)[(n - 1)(111)x(110)]，得到的结果表明，在存在 2 mM H(2)Q((aq))的情况下，电化学检测到的解吸-吸附过程选择性地发生在作为平台的有序 Pt(111) 域上，而在其他可用表面位点，即 Pt(110)台阶上，则发生不可逆吸附。后来，该域选择性电分析检测方案被用于选择性监测从优先取向的 Pt 纳米粒子表面上有序的纳米级 Pt(111) 域上解吸-吸附对苯二酚衍生的吸附层，证实了 Pt 纳米粒子表面上存在有序的（111）域。在有序 Pt(hkl)表面和优先取向的 Pt 纳米粒子上的电化学行为之间注意到很好的相关性。讨论了关键的学习和潜在的应用。结果证明了通过外部控制参数，即施加的电势，对纳米粒子进行域选择性脱帽的技术可行性。
