Surface Science最新文献

{"title":"Correlating structure, self-assembly chemistry and conductivity of trithiocyanuric acid on Au(111)","authors":"","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":null,"pages":null},"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":"","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":null,"pages":null},"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":"","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":null,"pages":null},"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":"","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":null,"pages":null},"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":"","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":null,"pages":null},"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}

{"title":"60 years of surface structure determination","authors":"","doi":"10.1016/j.susc.2024.122552","DOIUrl":"10.1016/j.susc.2024.122552","url":null,"abstract":"<div><p>A brief review is presented of the development and application of quantitative structural studies of surfaces in the last 60 years. The development of the earliest method, and the one that remains the benchmark technique, namely quantitative low energy electron diffraction (QLEED) is described, and its underlying methodology compared with alternative techniques that have emerged subsequently. In particular, the role of scanning tunnelling microscopy (STM) and density functional theory (DFT), a combination of methods that has typified many more recent surface structural studies, is compared and contrasted with ‘traditional’ quantitative experimental methods such as QLEED.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824001031/pdfft?md5=0eb96ac83d02e2ec5468e287adb20777&pid=1-s2.0-S0039602824001031-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141852594","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":"Synthesis of Van der Waals stretched antimonene via remote epitaxy","authors":"","doi":"10.1016/j.susc.2024.122548","DOIUrl":"10.1016/j.susc.2024.122548","url":null,"abstract":"<div><p>Two-dimensional antimonene with a honeycomb structure has attracted significant attention in recent years due to its novel properties and tunable electronic structure as varying applied in-plane strain. Yet, applying epitaxially strained antimonene is greatly limited by the strong coupling with the metal substrates. Here, we demonstrate the synthesis of the van der Waals stretched antimonene on graphene/Cu(111) substrate via remote epitaxy. It is found that, as corroborated by atomic force microscopy and reflection high-energy electron diffraction, the lattice of the antimonene can be remotely stretched by the underlying Cu(111). The graphene layer prevents antimonene from forming the surface alloy with Cu(111), which is also confirmed by Raman spectroscopy results. Our study not only provides a way to regulate the lattice of the epitaxial layers remotely but also provides a new idea for developing new potential topological materials.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141704573","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":"A direct Z-scheme GaTe/AsP van der Waals heterostructure: A promising high efficiency photocatalyst for overall water splitting with strong optical absorption and superior catalytic activity","authors":"","doi":"10.1016/j.susc.2024.122553","DOIUrl":"10.1016/j.susc.2024.122553","url":null,"abstract":"<div><p>The existing energy crisis and environmental pollution require an innovative approach to hydrogen production. Photocatalytic water-splitting has emerged as a potential solution, but the development of efficient photocatalysts remains the key challenge. Here, we employ first-principles calculations to investigate the structural, electronic, optical and photocatalytic characteristics of a van der Waals heterojunction comprising GaTe and AsP monolayers. The constructed GaTe/AsP heterojunction is thermodynamic, dynamical and thermal stable. The smaller indirect bandgap 1.68 eV than 2.21 eV and 2.45 eV for the constituent GaTe and AsP monolayers respectively, enhances the optical absorption of the GaTe/AsP heterojunction in visible and ultraviolet (UV) regions. The type-II band alignment of the GaTe/AsP heterojunction makes an efficient separation of photogenerated electrons and holes to different layers and extension their lifespans. The built-in electric field from GaTe side to AsP side induces a direct Z-scheme heterojunction photocatalyst with high redox reaction kinetic and high solar-to-hydrogen efficiency of 14.10 %. Our study demonstrates that the GaTe/AsP heterostructure is as efficient photocatalysts for overall water-splitting.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141716414","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":"Shuttleworth tension revisited","authors":"","doi":"10.1016/j.susc.2024.122546","DOIUrl":"10.1016/j.susc.2024.122546","url":null,"abstract":"<div><p>On a solid or liquid surface in thermodynamic equilibrium, the Shuttleworth tension is a sum of two pressures (or tensions) of different nature <span><math><mrow><mi>Υ</mi><mo>=</mo><mi>γ</mi><mo>+</mo><mover><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></mrow><mo>¯</mo></mover></mrow></math></span> (we consider only the diagonal component ’<span><math><mrow><mi>x</mi><mi>x</mi></mrow></math></span>’). The two pressures are parallel to the surface and are practically located in the surface monolayer. The surface area is <span><math><mrow><mi>A</mi><mo>=</mo><msub><mrow><mi>N</mi></mrow><mrow><mi>S</mi></mrow></msub><msubsup><mrow><mi>A</mi></mrow><mrow><mi>U</mi></mrow><mrow><mi>L</mi></mrow></msubsup></mrow></math></span>, <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>S</mi></mrow></msub></math></span> being the number of entities in the surface monolayer and <span><math><msubsup><mrow><mi>A</mi></mrow><mrow><mi>U</mi></mrow><mrow><mi>L</mi></mrow></msubsup></math></span> the area unit which is the Lagrangian surface area of one entity. The total energy includes the surface energetic term <span><math><mrow><mi>γ</mi><mi>A</mi></mrow></math></span>. Its derivative with respect to <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>S</mi></mrow></msub></math></span>, holding <span><math><msubsup><mrow><mi>A</mi></mrow><mrow><mi>U</mi></mrow><mrow><mi>L</mi></mrow></msubsup></math></span> constant, is the tension <span><math><msup><mrow><mi>γ</mi></mrow><mrow><mi>P</mi></mrow></msup></math></span>. It is <em>numerically</em> equal to the energy <span><math><mi>γ</mi></math></span>. The variation is of <em>chemical</em> nature and discontinuous. The surface monolayer has a chemical potential excess with respect to bulk for one entity (<span><math><mrow><mi>γ</mi><mspace></mspace><msubsup><mrow><mi>A</mi></mrow><mrow><mi>U</mi></mrow><mrow><mi>L</mi></mrow></msubsup><mo>=</mo><mi>Δ</mi><mi>μ</mi></mrow></math></span>). The other derivative, with respect to <span><math><msubsup><mrow><mi>A</mi></mrow><mrow><mi>U</mi></mrow><mrow><mi>L</mi></mrow></msubsup></math></span>, holding <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>S</mi></mrow></msub></math></span> constant, gives the pressure of <em>’elastic’</em> nature <span><math><mover><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></mrow><mo>¯</mo></mover></math></span>. It is <span><math><mrow><mi>∂</mi><mi>γ</mi><mo>/</mo><mi>∂</mi><msub><mrow><mi>ϵ</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></mrow></math></span>. For a solid, <span><math><mover><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></mrow><mo>¯</mo></mover></math></span> decreases rapidly with the temperature, while <span><math><mi>γ</mi></math></span> varies little. For a liquid and when neglecting <span><math><mover><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></mrow><mo>¯</mo></mover></math></span>,","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141696591","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":"Two-dimensional MoSeO/BP heterostructure for superior Z-scheme photocatalytic water splitting","authors":"","doi":"10.1016/j.susc.2024.122551","DOIUrl":"10.1016/j.susc.2024.122551","url":null,"abstract":"<div><p>The photocatalytic efficiency of traditional photocatalysts is usually frustrated by the easy recombination of photogenerated carriers and the lack of good compatibility between strong redox capacity and light response range. Two-dimensional (2D) Z-scheme heterostructures photocatalysts can solve these problems well. Based on first principles, the photocatalytic properties of 2D MoSeO/Boron phosphide (BP) heterostructures are systematically investigated. The results show that O-Mo-Se/BP heterostructure (with Se atoms close to BP layer) is a traditional type-II heterostructure, which lacks the redox capacity for photocatalytic water decomposition. However, Se–Mo–O/BP heterostructure (with O atoms close to BP layer) is a Z-scheme heterostructure, the built-in electric field can effectively separate the photogenerated carriers with higher redox ability. Meanwhile, the band edge positions with higher redox capacity straddle the water redox potentials for water splitting. Optical absorption shows that the heterostructure has a good light absorption capacity in UV–visible region. The power conversion efficiency (PCE) for this heterostructure is 15.9 %, which can be further improved to 18.7 % under external electric field. These results indicate that Se–Mo–O/BP heterostructure is a compelling direct Z-scheme candidate for photocatalytic water splitting.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141701925","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}