Surface Science最新文献

{"title":"Reactivity of graphene-supported Co clusters","authors":"Natalie J. Waleska-Wellnhofer ,&nbsp;Sophie Arzig ,&nbsp;Fabian Düll ,&nbsp;Udo Bauer ,&nbsp;Phiona Bachmann ,&nbsp;Johann Steinhauer ,&nbsp;Christian Papp ,&nbsp;Thomas Risse","doi":"10.1016/j.susc.2024.122573","DOIUrl":"10.1016/j.susc.2024.122573","url":null,"abstract":"<div><p>Graphene-supported Co clusters were investigated by high-resolution XPS, TPD and IRRAS using CO as a probe molecule. CO adsorption was observed at edge, on-top and bridge/hollow sites on the as-prepared clusters. Temperature-programmed XPS showed CO dissociation at <em>T</em> &gt; 300 K. The CO desorption temperatures were determined by TPD measurements to be 260, 320 and 400 K for CO^{bridge/hollow}, CO^edge and CO^top, respectively. The CO dissociation products were used to investigate the adsorption of CO on carbon and oxygen precovered Co clusters. Site blocking by these adatoms was found resulting in the absence of CO^edge (XPS and TPD) and a decrease of the CO adsorption capacity (XPS, TPD and IRRAS). Additionally, no CO dissociation was found on the precovered clusters concluding a blocking of the catalytically active sites which are the edge sites of the clusters.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122573"},"PeriodicalIF":2.1,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824001249/pdfft?md5=f0efb24aabd34a82bbfdb2d83ad2742c&pid=1-s2.0-S0039602824001249-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142002473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The surface chemistry of the atomic layer deposition of ruthenium on aluminum and tantalum oxide surfaces","authors":"Xiangdong Qin ,&nbsp;Francisco Zaera","doi":"10.1016/j.susc.2024.122572","DOIUrl":"10.1016/j.susc.2024.122572","url":null,"abstract":"<div><p>The surface chemistry of Ru atomic layer deposition (ALD) processes based on the use of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)ruthenium(III) (Ru(tmhd)₃) and either molecular oxygen or atomic hydrogen on aluminum oxide films was characterized by a combination of surface-sensitive techniques. The thermal decomposition of the Ru metalorganic precursor was determined, by using a combination of reflection-absorption infrared spectroscopy (RAIRS), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS), to start below 400 K and to take place in a stepwise fashion over a wide range of temperatures. Gas-phase products from this chemistry include 2,2,6,6-tetramethyl-3,5-heptanedione (the protonated ligand, Htmhd; in a TPD peak at 520 K), isobutene (540 K; indicating the fragmentation of the organic ligands), and other products from isomerization and/or aldol condensation (650 and 730 K). This chemistry is accompanied by the reduction of the Ru³⁺ ions in two stages, involving the loss of some of their ligands and their direct bonding to the substrate first (between 500 and 600 K) and a full reduction to a metallic state later on (600–700 K). ALD cycles using either molecular oxygen or atomic hydrogen resulted in the slow build-up of Ru on the surface, but the co-deposition of carbon could not be avoided, at least in the initial cycles, while the alumina surface was still exposed. With O₂, the Ru atoms alternate between partially-oxidized (after the O₂ exposures) and zero-valent (after the Ru(tmhd)₃ doses) states, and some Ru loss in the form of the volatile RuO₄ oxide was seen after the second half of the ALD cycles; neither the Ru oxidation state alternation nor the elimination of some Ru from the surface were observed when using H·. The deposited Ru was determined, by combining results from angle-resolved XPS (ARXPS) and low-energy ion scattering (LEIS) experiments, to grow as 3D nanoparticles rather than as a layer-by-layer 2D film, presumably because the Ru precursor preferentially adsorbs (and decomposes more cleanly) on the metal surface. A discussion is provided of the implications of these results for the design of ALD processes.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122572"},"PeriodicalIF":2.1,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141991380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The stereochemistry of 1,4-dicarboxylic acids on Cu(110): Sergeants & soldiers, surface explosions and chiral reconstructions","authors":"Karl-Heinz Ernst","doi":"10.1016/j.susc.2024.122569","DOIUrl":"10.1016/j.susc.2024.122569","url":null,"abstract":"<div><p>Dicarboxylic acids, including tartaric acid, have played a crucial role alongside amino acids in the study of chiral recognition on metal surfaces. Over the past two decades, significant insights into surface stereochemistry have emerged, particularly on Cu(110). This review examines various phenomena observed during the interaction of 1,4-dicarboxylic acids with the Cu(110) surface. We explore diverse aspects such as chiral surface reconstructions, intermolecular chiral recognition, stereoselective autocatalytic decomposition, and chiral symmetry breaking through doping.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122569"},"PeriodicalIF":2.1,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824001201/pdfft?md5=3afd3c5e7aafb532a72111869d65f114&pid=1-s2.0-S0039602824001201-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141929838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Substrate-modulation effect in on-surface synthesis","authors":"Tianchen Qin ,&nbsp;Baiyao Liang ,&nbsp;Lei Hu ,&nbsp;Junfa Zhu","doi":"10.1016/j.susc.2024.122568","DOIUrl":"10.1016/j.susc.2024.122568","url":null,"abstract":"<div><p>The substrate-modulation effect permeates throughout the realm of surface chemistry, particularly in the field of on-surface reactions. A comprehensive understanding of the interactions between molecules and substrates is crucial for the selective synthesis of designed graphene-based materials. In this review, we examine the substrate-modulation effect of surface-assisted reactions, focusing on the reaction mechanisms. We begin by elucidating how the substrates influence various process of the surface-assisted reaction, including adsorption, migration, and reaction of molecules. Additionally, substrates act as charge donors and acceptors to facilitate charge transfer between substrates and molecules, thereby tuning the electronic structure of the molecules.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122568"},"PeriodicalIF":2.1,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141929865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bi layers on the Mo(112) surface: A DFT study","authors":"I.N. Yakovkin,&nbsp;N.V. Petrova","doi":"10.1016/j.susc.2024.122567","DOIUrl":"10.1016/j.susc.2024.122567","url":null,"abstract":"<div><p>Relativistic DFT calculations performed for Bi layers adsorbed on the Mo(112) surface have shown that Bi atoms tend to occupy adsorption sites in furrows and, at a half-monolayer coverage, form a rectangular p(2 × 1) structure. For a complete Bi monolayer, the most preferred structure is the centered c(2 × 1) structure, with one half of Bi adatoms in on-row sites. No Bi-induced surface states have been indicated along Γ – X, corresponding to the direction along furrows, which can explain only minor changes in the band structure and density of states in vicinity of E_F with increasing Bi coverage. On the contrary, changes in the band structure along Γ – Y turn out to be very significant. Specifically, the SOC-splitting band, associated with surface states generated by the Bi adlayer, moves upward and twice crosses E_F thus becoming a valence band. This feature may be important in the search for new layered structures for nano and spin-electronics.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122567"},"PeriodicalIF":2.1,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141848844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlating structure, self-assembly chemistry and conductivity of trithiocyanuric acid on Au(111)","authors":"Robert Bavisotto ,&nbsp;Dustin Olson ,&nbsp;Wilfred T Tysoe","doi":"10.1016/j.susc.2024.122556","DOIUrl":"10.1016/j.susc.2024.122556","url":null,"abstract":"<div><p>The majority of candidates for simple model molecular-electronic components consist of a conductive π-conjugated hydrocarbon linker attached to at least two anchoring groups, such as thiols or isocyanides. It has been found that select molecules self-assemble on gold surfaces, creating one-dimensional conductive structures that act as “molecular wires”. Furthermore, these oligomers can form molecular bridges between gold nanoparticles, leading to the creation of simple molecular-electronic devices. This raises the question whether other π-conjugated molecular linkers could exhibit similar behavior that might offer a broader range of candidates for fabricating electronic devices. Trithiocyanuric acid (1,3,5-triazine-2,4,6-trithiol, TTCA) provides a possible candidate. TTCA (C₃N₃(SH)₃) can exist as a trithiol or as a trithione in which hydrogens transfer to the sulfurs so that they are present with three C=N groups within the ring. TTCA exists naturally in the trithione form but converts into a trithiol when adsorbed onto an Ag(111) where it is vertically oriented. The structure of TTCA adsorbed on Au(111) is studied here using reflection-absorption infrared spectroscopy (RAIRS) where it is found to remain as the trithione isomer, but changes orientation as the coverage increases. Scanning-tunneling microscopy (STM) reveals that TTCA oligomerizes on Au(111) to form chains and triangular structures. The influence on molecular conductivity due to the differences in the adsorbate's isomeric structure was investigated using devices comprising either silver or gold nanoparticles deposited in the gap between gold nanoelectrodes. Both devices were found to conduct when dosed with TTCA, but the devices fabricated using silver were about 13 time more conductive than those made from gold nanoparticles, consistent with the π-conjugated structure formed on silver but not on gold. This implies that oligomers form both on silver and on gold and potentially increases the range of molecule-metal combinations that might be used to fabricate molecular-electronic devices.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122556"},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using Auger transitions as a route to determine the oxidation state of copper in high-pressure electron spectroscopy","authors":"Markus Soldemo ,&nbsp;Fernando Garcia-Martinez ,&nbsp;Christopher M Goodwin ,&nbsp;Patrick Lömker ,&nbsp;Mikhail Shipilin ,&nbsp;Anders Nilsson ,&nbsp;Peter Amann ,&nbsp;Sarp Kaya ,&nbsp;Jonas Weissenrieder","doi":"10.1016/j.susc.2024.122565","DOIUrl":"10.1016/j.susc.2024.122565","url":null,"abstract":"<div><p>Accurate discrimination between metallic copper (Cu⁰) and cuprous oxide (Cu₂O, Cu⁺) in electron spectroscopy commonly relies on the Auger electron spectroscopy (AES) Cu L₃M_4,5M_4,5 transitions, as the X-ray photoelectron spectroscopy (XPS) Cu core-levels do not provide large enough binding energy shifts. The kinetic energy of the AES Cu L₃M_4,5M_4,5 electrons is ∼917 eV, which leaves the AES electron susceptible for efficient scattering in the gas phase and attenuation of the signal above near-ambient pressure conditions. To study copper-based materials at higher pressures, e.g., the active state of a catalyst, Auger transitions providing electrons with higher kinetic energies are needed.</p><p>This study focuses on AES transitions involving the Cu K-shell (1s electrons) that exhibit discernible kinetic energy shifts between the oxidation states of Cu. It is shown that the AES Cu KL₂M_4,5 transition, with kinetic energy of ∼7936 eV, provides a large enough kinetic energy shift between metallic copper and Cu₂O. AES signal is demonstrated in an ambient of 150 mbar CO₂.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122565"},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S003960282400116X/pdfft?md5=4fdbf89520066107d67767248dbe3449&pid=1-s2.0-S003960282400116X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thoughts on the past, present and future of UHV surface chemistry and the birth of Single-Atom Alloys","authors":"Audrey Dannar,&nbsp;E. Charles H. Sykes","doi":"10.1016/j.susc.2024.122566","DOIUrl":"10.1016/j.susc.2024.122566","url":null,"abstract":"<div><p>Throughout its relatively short lifetime, ultra-high vacuum (UHV) surface chemistry has progressed quickly. In the 1960′s, pioneers like Ertl and Somorjai started the field using single crystals and gained significant insight into catalytic processes by relating surface structure to reactivity. The more recent proliferation of scanning probes has significantly increased the power of the single crystal approach by enabling the atomic-scale structure of active sites to be correlated with their reactivity. In this perspective we briefly discuss how the field developed, identify some challenges, and highlight <em>Single-Atom Alloys</em> (SAAs), a new class of heterogeneous catalyst that was developed from a fundamental surface science approach. However, despite recent successes, funding for fundamental surface science has declined. Academic hires in the discipline are also declining in part due to the start-up costs. We make the case that fundamental UHV surface chemistry is still too young a field to be in recession.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122566"},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141849723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Straight sections of step edges on a NiAl(110) curved single crystal surface used to calculate an approximation of step formation energy","authors":"Jessika M. Piñeiros-Bastidas ,&nbsp;Sabine V. Auras ,&nbsp;Ludo B.F. Juurlink","doi":"10.1016/j.susc.2024.122545","DOIUrl":"10.1016/j.susc.2024.122545","url":null,"abstract":"<div><p>Curved crystals may feature a smooth transition between different vicinal surfaces. Using one curved single crystal to study different vicinal surfaces requires less experimental time than using several single flat crystals. Here, we study step distributions on the (110) plane of a curved NiAl single-crystal surface, which consists of alternating Ni and Al atom rows. We use scanning tunneling microscopy under UHV conditions at room temperature and our home-built Python-based analysis script to obtain statistical information on kink and straight sections along step-edge distributions from STM images. We perform this analysis mainly to study this single crystal’s kink distributions and step termination We propose a new method to estimate the step formation energy based on step edge analysis and statistical mechanics. With this method, we find an approximation of the step formation energy for NiAl(110).</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122545"},"PeriodicalIF":2.1,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824000967/pdfft?md5=549c2d6afa350cc1827a6642b3b374cf&pid=1-s2.0-S0039602824000967-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen, oxygen, and hydrogen bonding and thermal stability of ambient exposed nitrogen-terminated H-diamond (111) surfaces studied by XPS and HREELS","authors":"Mohan Kumar Kuntumalla,&nbsp;Shaul Michaelson,&nbsp;Alon Hoffman","doi":"10.1016/j.susc.2024.122555","DOIUrl":"10.1016/j.susc.2024.122555","url":null,"abstract":"<div><p>We report on the chemical composition, bonding, and in-vacuum thermal stability (up to 1000 °C) of nitrogen plasma terminated H-Diamond(111) (H-Di(111)) surfaces followed by ambient exposure. The nitrogen-plasma exposures include radio frequency (RF) (at pressure: 3 × 10⁻² (damaging) and 7 × 10⁻² Torr (non-damaging)) and microwave (MW) nitrogen plasmas and studied by X-ray photoelectron spectroscopy (XPS) and high resolution electron energy loss spectroscopy (HREELS). The largest nitrogen intake was observed upon exposure to RF(N₂) damaging plasma, followed by MW(N₂) and non-damaging RF(N₂) plasmas. A similar trend follows the adsorption of adventitious oxygen. The XPS analysis shows that most of the adventitious oxygen is adsorbed in a CO_x configuration upon nitride surfaces exposure to ambient conditions. However, upon high temperature annealing of the damaging RF(N₂) plasma exposed surface, some NO_x (species) were detected by XPS. From the HREELS analysis, the hydrogen adsorbed on the H-Di(111) is not fully removed by exposure to the different nitrogen plasmas. These measurements show that NH(ads) species are formed on the surface and are desorbed upon vacuum annealing in the 500–700 °C range. This study may be of importance in all ex-situ applications influenced by the near-surface physicochemical and electronic properties of nitrogen-terminated H-Di(111) surfaces.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"749 ","pages":"Article 122555"},"PeriodicalIF":2.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141852994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}