Ab initio modeling of the bonding of benzotriazole corrosion inhibitor to reduced and oxidized copper surfaces
Ab initio modeling of the bonding of benzotriazole corrosion inhibitor to reduced and oxidized copper surfaces
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DOI：
10.1039/c4fd00257a
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发表时间：
2015-01-01
影响因子：
3.4
通讯作者：
Kokalj, Anton
中科院分区：
文献类型：
--
作者：
Kokalj, Anton
基于密度泛函理论（DFT）计算，讨论了苯并三唑（一种出色的铜缓蚀剂）在还原铜和氧化铜表面上的键合。计算表明，苯并三唑能够与无氧化物和氧化的铜表面结合，并且在这两种表面上，它与配位不饱和铜位点的结合力明显更强。这表明苯并三唑能够钝化反应性欠配位表面位点，这些位点是可能发生腐蚀攻击的微观位点。苯并三唑可以多种不同形式吸附，但仅以去质子化形式形成牢固的分子-表面键。当去质子化形式掺入有机金属复合物时，键合更加牢固。这与现有的实验证据一致，即苯并三唑通过形成保护性有机金属络合物来抑制腐蚀。进一步表明，苯并三唑的吸附显着降低了金属功函数，这是大的永久分子偶极子和适当定向的吸附结构的结果。有人认为，对功函数的这种显着影响可能与腐蚀抑制有关，因为它应该减少阳极腐蚀反应，这与现有的实验证据一致，即苯并三唑虽然是混合型抑制剂，但主要影响阳极反应。
The bonding of benzotriazole-an outstanding corrosion inhibitor for copper-on reduced and oxidized copper surfaces is discussed on the basis of density functional theory (DFT) calculations. Calculations reveal that benzotriazole is able to bond with oxide-free and oxidized copper surfaces and on both of them it bonds significantly stronger to coordinatively unsaturated Cu sites. This suggests that benzotriazole is able to passivate the reactive under-coordinated surface sites that are plausible microscopic sites for corrosion attack. Benzotriazole can adsorb in a variety of different forms, yet it forms a strong molecule-surface bond only in deprotonated form. The bonding is even stronger when the deprotonated form is incorporated into organometallic adcomplexes. This is consistent with existing experimental evidence that benzotriazole inhibits corrosion by forming protective organometallic complexes. It is further shown that adsorption of benzotriazole considerably reduces the metal work function, which is a consequence of a large permanent molecular dipole and a properly oriented adsorption structure. It is argued that such a pronounced effect on the work function might be relevant for corrosion inhibition, because it should diminish the anodic corrosion reaction, which is consistent with existing experimental evidence that benzotriazole, although a mixed type inhibitor, predominantly affects the anodic reaction.