Study of molecule on metal nanoparticle materials with clarification function from the composite materials point of view

研究含硫分子在过渡金属表面的吸附体系具有重要意义。希望为生产新型汽车催化剂、脱硫催化剂和医药提供参考，并获得有益的知识。本研究利用近边x射线吸收精细结构（NEXAFS）和同步加速器x射线光电子能谱（XPS）研究了l -半胱氨酸、（CH_3）_2S和C_2H_5SH分子在Cu（100）或Rh（100）单晶表面的吸附行为。此外，我们还尝试用Rh（PVP）纳米粒子制备了一种新的功能化薄膜表面，并成功地找到了一些制备Pd纳米粒子的合适参数。对于l -半胱氨酸在Cu（100）表面的吸附体系，1^<st>层l -半胱氨酸解离并以硫代形状吸附在Cu（100）表面。在l -半胱氨酸的2^<和>吸附层中，adlayer分子与1^<st…More >层分子成键。这两个l -半胱氨酸分子形成一个较暗的分子。对于l -半胱氨酸和水共吸附的分子体系，S-C键轴的取向角发生了变化。这说明共吸附的水分子对l -半胱氨酸硫原子的环境有影响。在Rh（l00）表面对（CH_3）_2S和C_2H_5SH的吸附体系中，有两种吸附情况。一种是硫酸盐分子吸附在表面。在另一种情况下，被吸附的分子没有任何解离。这两种情况都很大程度上取决于衬底温度。分子内S-C键和S-H键的存在似乎使表面反应有很大差异，并取决于这些键的存在。对于纳米颗粒的制备，我们尝试用PVP（聚乙烯吡咯烷酮）作为表面活性剂分子来制备Rh纳米颗粒。从这些Rh纳米颗粒的结果来看，我们已经成功地制造出了具有许多“纳米孔”的薄膜，其直径从几纳米到100纳米不等。此外，我们还成功地制备了另一种钯纳米粒子，其制备方法与湿法制备方法不同。事实上，钯纳米粒子的表面在室温下不易氧化。然而，我们制备的钯纳米粒子在相同的条件下很容易被氧化。此外，在获得的XPS和NEXAFS光谱中还存在一些效应，这些效应源于纳米颗粒的性质（即尺寸效应）。少

It is important to investigate an adsorption system of a sulfur-including molecule on transition metal surface. The investigation is hoped to bring a production for a new automobile catalyst, desulfurization catalyst and medicine, and also to obtain an useful knowledge. In this study, we have investigated an adsorption behaviors for L-Cysteine, (CH_3)_2S and C_2H_5SH molecules on Cu(100) or Rh(100) single crystal surfaces by means of Near-Edge X-ray Absorption Fine Structure (NEXAFS) and X-ray Photoelectron Spectroscopy (XPS) with synchrotron light. Moreover we have tried to fabricate an new functionalized thin film surface with using the Rh(PVP) nanoparticles and succeeded to find out some suitable parameters for producing the Pd nanoparticles.For the adsorption system of L-Cysteine on Cu(l00) surface, the 1^<st> layer L-Cysteine dissociates and adsorbs on the surface as the thiolate shape. In the 2^<nd> adsorption layer of L-Cysteine, the adlayer molecule has a bonding with the 1^<st … More > layer molecule. Those two L-Cysteine molecules form a dimmer molecule. For a co-adsorption molecular system of those L-Cysteine and water, the orientation angle of the S-C bonding axis changes. This result implies that the co-adsorbed water molecule has an effect on the environment of the sulfur atom of L-Cysteine. In case of the adsorption system for (CH_3)_2S and C_2H_5SH on Rh(l00) surface, there are two adsorption cases. One is thiolate molecule adsorbs on the surface. In the other case, the adsorbed molecules do not have any dissociation. Both cases much depend upon a substrate temperature. It seems about the presence of the intramolecular S-C and S-H bondings that the surface reactions have much difference and depend on the existence of those bondings. For the fabrication of the nanoparticles, we have tried to fabricate the Rh nanoparticles with using PVP (poly vinylpyrrolidone) as a surfactant molecule. Judging from the results for those Rh nanoparticles, we have succeeded to produce a thin film with many "nanoholes", which diameter is from several nm to 100 nm size. Moreover we have also succeeded to fabricate another Pd nanoparticles, which are made by the different method in comparison with the wet process. Indeed the surface of the Pd nanoparticles is not easily oxidized under the air environment at room temperature. However it clear that our fabricated Pd nanoparticles can be oxidized easily in the same condition. In addition there are some effects, which originate with the nanoparticles nature (i.e.size effect) in the obtained XPS and NEXAFS spectra. Less