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表面增强拉曼光谱在铁腐蚀与防护研究中的应用 总被引:1,自引:0,他引:1
综述了近年来表面增强拉曼光谱(SERS)在铁表面腐蚀与防护方面的应用和研究进展。作为一种能够在分子水平上提供物质结构信息的技术,SERS被广泛应用在金属特别是铁腐蚀与防护的研究中。文章主要从铁表面SERS增强理论模型、缓蚀剂在铁表面的吸附方式和铁电极上氧化或钝化膜的结构3个方面来展示SERS技术的应用,并展望了进一步研究的方向。 相似文献
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利用共焦显微拉曼系统研究了乙醇溶剂中2 巯基苯并噻唑(HMBT)在不同pH条件下吸附在ORC法粗糙化处理所得铁表面的SERS光谱。结果表明2 巯基苯并噻唑分子在酸性和中性溶液中通过环外S或环内N原子吸附于铁表面,而在碱性溶液中分子失去氢原子,并通过静电相互作用吸附于铁表面上。 相似文献
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采用基于密度泛函理论的第一性原理方法研究了氢原子和氢分子在纯铁表面和锰原子掺杂表面的吸附与解离行为.研究结果表明,氢原子可在纯铁(001)表面稳定吸附,吸附能按照顶位,桥位和心位依次增强;而溶质原子锰降低了氢原子距离表面的位置并强化了氢原子的吸附行为.氢分子在纯铁表面的吸附解离行为取决于氢分子距离模型表面的初始距离和初始空间构型.氢分子平行于纯铁(001)表面时,距离心位1.2?发生解离,而桥位、顶位均不会发生解离;氢分子垂直放置时,距离桥位0.6?、顶位1.0?发生解离,心位不会发生解离.氢分子平行于锰掺杂纯铁(001)表面时,距离桥位0.6?、顶位0.7?、心位1.2?发生解离;氢分子垂直放置时,距离桥位、心位0.8?发生解离,而顶位放置氢分子不发生解离.归纳可知,锰溶质原子掺杂会增加铁基体表面氢原子和氢分子的吸附作用并促进氢分子发生分解. 相似文献
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利用第一性原理方法研究了一氧化碳分子在本征和硼、氮、铝、磷掺杂的有限尺寸石墨烯上的吸附机理.结果表明,石墨烯作为一氧化碳传感器时的性能依赖于掺杂元素.本征、硼和氮掺杂石墨烯吸附一氧化碳时的吸附能较低,为物理吸附.铝、磷掺杂石墨烯的吸附能显著提高,比本征、硼和氮掺杂时高出约一个数量级,且铝和磷原子从石墨烯中突出,使其发生局部弯曲.铝掺杂石墨烯增强了石墨烯与一氧化碳分子之间的相互作用,可以提高石墨烯的气敏性和吸附能力,是一氧化碳传感器的最佳候选材料之一. 相似文献
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采用FT-IR、X射线光电子能谱以及基于周期平面波的DFT方法分别研究了乙酰氧肟酸钠(aHA)在针铁矿或赤铁矿表面上的吸附结构,并将计算得到的光电子能谱移动和电荷转移实验得到的XPS结果进行对比.红外结果显示aHA可能以五元环螯合物形式吸附于针铁矿或赤铁矿表面,DFT计算结果表明aHA中氧肟酸基团的两个氧原子与针铁矿(101)或(100)表面上的一个铁原子形成五元环结构,同时氧肟酸基团中的两个氧还相应的与针铁矿表面邻近两个铁原子成键,但氧肟酸基团中的两个氧原子却只与赤铁矿(001)表面上的一个铁原子形成五元环结构.对于针铁矿(101)、(100)和赤铁矿(001)表面上吸附位点对应的铁原子,计算得到的光电子能谱移动与实验得到的光电子能谱移动基本相等,说明了计算结果的可靠性和所得吸附结构的合理性. 相似文献
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本文用密度泛函理论(DFT)的总能计算研究了一氧化碳和氢原子在Ni(111)表面上p(2×2)共吸附系统的原子结构和电子态,结果表明CO和H原子分别被吸附于两个对角p(1×1)元胞的hcp和fcc位置.以氢分子和CO分子作为能量参考点,总吸附能为2.81 eV,相应的共吸附表面功函数φ为6.28 eV.计算得到的C—O,C—Ni和H—Ni的键长分别是1.19?, 1.96?和 1.71?,并且CO分子以C原子处于hcp的谷位与金属衬底原子结合.衬底Ni(111)的最外两层的晶面间距在吸附后的相对变化分别是
关键词:
Fisher-Tropsch反应
催化作用
Ni(111) p(2×2)/(CO+H)
共吸附 相似文献
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The coadsorption of carbon oxide (CO) and nitrogen oxide (NO) molecules on the surface of nickel nanoclusters formed on a
thin magnesium oxide MgO(111) film grown on the Mo(110) face in an ultrahigh vacuum is studied by reflective infrared spectroscopy
and thermodesorption spectroscopy (TDS). The adsorption of NO molecules is found to substantially change the state of the
initially adsorbed CO molecules. The TDS and IR spectra suggest that the adsorption of NO molecules stimulates the surface
migration of CO molecules from the surface of metallic clusters to the cluster-oxide interface, which is accompanied by a
decrease in the angle of inclination of the molecular axis to the surface. 相似文献
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T. T. Magkoev 《Russian Physics Journal》2005,48(5):536-540
The joint adsorption of CO and NO molecules on the surface of nanodimensional nickel clusters formed on the Mo(110) face of
a thin MgO(111) magnesium oxide film under conditions of ultrahigh vacuum is investigated by methods of infrared reflection
and thermal desorption spectroscopy. It is revealed that the adsorption of the NO molecules changes significantly the state
of the adsorbed CO molecules. Based on an analysis of thermal desorption and IR spectra, a conclusion can be drawn that the
adsorption of the NO molecules stimulates the migration of the CO molecules from the metal cluster surface to the boundary
between the cluster and oxide accompanied by a decrease in the tilt angle of the molecular axis to the surface.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 85–89, May, 2005. 相似文献
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Using angle resolved UV photoelectron spectroscopy, coupled with the continuum of polarized light available with synchrotron radiation, we make an interpretation of the photoelectron spectrum of CO adsorbed on Cu(100). We point out that the bonding of CO on Cu as observed by photoemission is considerably different from the bonding of CO on Ni. These differences do not seem to be caused by bonding orientation differences, however, as the CO molecular axis is found to be very close to the surface normal, as was the case for CO on Ni(100). No evidence is found for a second phase of CO on Cu(100). 相似文献
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We have studied the adsorption of CO on clean and oxygen-preadsorbed Cu(110) by means of u.v.-photoemission. A new interpretation of the adsorbate induced structures is presented. Despite the low adsorption energy of CO and Cu, we find that the 5ρ-derived level is located at a higher binding energy than it is in CO adsorbed on Ni. We suggest that the position of this level is determined by interaction with low lying electron states in Cu. Also, the 4ρ derived level is found at a higher binding energy on Cu than on Ni, as an effect of smaller extramolecular relaxation on Cu. Detailed angle resolved studies of the CO/Cu(110) system suggest that the CO molecule is adsorbed with the molecular axis at about 35° relative to the surface normal. 相似文献
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The adsorption of O2 and CO on the Si(111) surface was studied by low-energy helium ion scattering. The adsorption consists of a fast adsorption stage followed by a much slower Sorption process. In the final uptake region CO has a faster rate of increase than O. There is no evidence of He+ scattering from C atoms. This fact excludes the CO molecule having its axis parallel to the surface. A comparison of the intensities of the substrate (Si) signals, for the same recorded oxygen content on the surface, shows that carbon monoxide shadows the Si atoms more than oxygen does. An increase in the oxygen signal was observed even after exposures in the range of 1014–1015 molecules cm?2. No substantial diffusion of CO into the bulk can be deduced from these results. Desorption of oxygen by He+ ions was observed by following the adsorbate and substrate signals as a function of time. The sputtering cross-section has a maximum for an impact angle of 25° relative to the surface. 相似文献
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从各向同性介质和各向异性单轴晶体界面间的菲涅耳公式出发,进一步研究了当自然光从各向同性介质射向各向异性且光轴任意取向的单轴晶体界面上时,其反射光成为垂直入射面的线偏振光时所对应的入射角,即布儒斯特角是否存在的问题,并对该问题进行了较全面的论述,计算了相应条件下的布儒斯特角和有关参量的数值,得到了正确的结论,同时也指出了某些文献在论述该问题时的不妥之处. 相似文献
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Electronic structure for CO chemisorbed on Pd (210) surface has been calculated by the model potential Xα method which involves Bonifacic-Huzinaga's model potential and Slater's Xα potential. The results of the present calculations are consistent with the “inclined” CO model which was proposed by Madey et al. The results also show that the electronic structure of CO chemisorbed on Pd (210) surface resembles surprisingly those of CO on the other low-index planes where the CO molecular axis is supposed to be perpendicular to the surfaces. 相似文献
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《Surface science》1995,325(3):L421-L427
We use thermal desorption spectroscopy to estimate the adsorption energy of CO on NiO(100) to be 7.0–8.8 kcal mol−1. NEXAFS is employed to determine the orientation of the CO axis. The molecule is oriented perpendicular to the NiO(100) surface. In the present case we have resorted to angle-resolved photoelectron spectroscopy (ARUPS) to find indications that the CO molecule interacts with the surface through its carbon lone pair. The experimental analysis is in agreement with theoretical predictions that CO is held to NiO(100) mainly via electrostatic multipolar forces. 相似文献