Hydroxyl Radicals Attack Metallic Gold
Hydroxyl Radicals Attack Metallic Gold
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DOI：
10.1002/anie.200906358
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Scholz, Fritz
中科院分区：
文献类型：
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作者：
Nowicka, Anna Maria;Hasse, Ulrich;Scholz, Fritz
金由于其抗氧化性以及其电、磁、光和其他物理特性而用于各种目的。金是电子工业、光学和电化学中最重要的材料之一。[1-3]金的表面光滑度和清洁度至关重要，特别是对于光学和电化学应用。对于金的表面清洁和平滑，已经报道了许多物理，化学和电化学方法;[3-10]然而，迄今为止还没有报道仅溶解金表面上的粗糙体的工具。金属金作为植入材料广泛应用于医学领域。[11这样的金植入物将金释放到邻近组织中，并且假设通过氧化的免疫反应发生释放。[13]在此，我们报告了意想不到的实验结果，其显示芬顿试剂中的OHC自由基快速地从机械抛光的金表面溶解金，从而产生更光滑的表面，即化学抛光的表面。OHC自由基优先溶解作为表面上存在的小粗糙体的一部分的金原子，即使在仔细的机械抛光之后。反应在微凸体溶解后终止。报道的效果可以解释金从医疗植入物中的释放，并且它可以用于抛光各种应用的金。虽然众所周知，芬顿试剂的OHC自由基可以快速溶解Au电极上相当稳定的烷基硫化物自组装单层[14]，但对裸露的Au表面的攻击是出乎意料的，因为金以其氧化稳定性而闻名，除非金离子被强烈络合，例如在氰化物溶液中。
Gold is used for various purposes because of its resistance to oxidation and its electrical, magnetic, optical, and other physical properties. Gold is one of the most important materials in the electronics industry, for optics, and in electrochemistry as an electrode material.[1–3] The surface smoothness and cleanness of gold is of utmost importance, in particular for optical and electrochemical applications. For surface cleaning and smoothing of gold, a number of physical, chemical, and electrochemical methods have been reported;[3–10] however, a tool for dissolving only the asperities on a gold surface has not been reported to date. Metallic gold is widely used in medicine as implant material.[11, 12] Such gold implants release gold into the adjacent tissue and it was hypothesized that the release occurs by an immune reaction by oxidation.[13]Herein, we report unexpected experimental results showing that OHC radicals in Fenton s reagent quickly dissolve gold from a mechanically polished gold surface to lead to a much smoother, that is, chemically polished, surface. The OHC radicals preferentially dissolve the gold atoms that are part of small asperities present on the surface, even after careful mechanical polishing. The reaction terminates after dissolution of the asperities. The reported effect can explain the release of gold from medical implants, and it may be used for polishing gold for various applications. Although it is well known that the OHC radicals of Fenton s reagent rapidly dissolve the rather stable self-assembled monolayers of alkyl sulfides on Au electrodes,[14] attack on a bare Au surface was unexpected because gold is known for its stability towards oxidation unless the gold ions are strongly complexed, as, for example, in cyanide solutions.