Surface SciencePub Date : 2024-08-28DOI: 10.1016/j.susc.2024.122581
{"title":"Formation and coarsening of epitaxially-supported metal nanoclusters","authors":"","doi":"10.1016/j.susc.2024.122581","DOIUrl":"10.1016/j.susc.2024.122581","url":null,"abstract":"<div><div>This mini-review describes developments over the last ∼30 years in characterizing the nucleation & growth of epitaxially-supported metal nanoclusters (NCs) or islands during vapor deposition, as well as their post-deposition coarsening. A beyond-mean-field treatment for homogeneous nucleation & growth corrects the deficiencies of traditional treatments in describing, e.g., the island size distribution, but also necessitates consideration of the spatial distribution of islands and their capture zones. We discuss advances in modeling capabilities, including those based upon on an ab-initio level treatment of periphery diffusion kinetics, for description of the non-equilibrium growth shapes of these NCs, focusing on 2D NCs. For post-deposition coarsening of arrays of NCs, there is generally a competition between Ostwald Ripening (OR) and Smoluchowski Ripening (SR). SR is also known as Particle Migration & Coalescence. For 2D NCs in homoepitaxial systems, conventional OR is observed on pristine fcc(111) surfaces, dramatically enhanced OR in the presence of even trace amounts of chalcogens for Cu(111) and Ag(111), and anomalous OR on anisotropic fcc(110) surfaces. The unexpected discovery of SR for fcc(100) homoepitaxial systems prompted extensive analysis of the underlying diffusivities of 2D NCs as a function of size, as well as of NC coalescence dynamics. A comprehensive understanding of these processes is now available. Self-assembly of 3D NCs during deposition, issues related to heterogeneous nucleation, directed assembly, NC growth structure selection, and coarsening are addressed. For SR of 3D epitaxial NCs, recent insights into the size-dependence of diffusivity are described.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532020","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}
Surface SciencePub Date : 2024-08-28DOI: 10.1016/j.susc.2024.122594
{"title":"Two-dimensional conjugated metal–organic frameworks grown on a MoS2 surface","authors":"","doi":"10.1016/j.susc.2024.122594","DOIUrl":"10.1016/j.susc.2024.122594","url":null,"abstract":"<div><p>Molybdenum disulfide (MoS<sub>2</sub>) features an atomically flat surface without dangling bonds. Molecular self-assembly on this surface provides an effective route to constructing heterostructure devices. In this work, we show the successful synthesis of M<sub>3</sub>(1,4,5,8,9,12-hexaazatriphenylene, HAT)<sub>2</sub> (<em>M</em> = Ni, Co) conjugated metal–organic frameworks (<em>c</em>-MOFs) on a MoS<sub>2</sub> surface. In the frameworks, HAT molecules constitute a honeycomb lattice while the metal atoms constitute a Kagome lattice. The random orientations of the frameworks with respect to the substrate and irregular domain shapes indicate that the frameworks interact weakly with the MoS<sub>2</sub>. The successful synthesis of 2D <em>c</em>-MOFs on inert substrates opens a door for the construction of advanced 2D van der Waals heterojunctions.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142121952","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}
Surface SciencePub Date : 2024-08-26DOI: 10.1016/j.susc.2024.122591
{"title":"Modulation of monolayer SnSe2 optoelectronic properties by applied electric field and atomic doping","authors":"","doi":"10.1016/j.susc.2024.122591","DOIUrl":"10.1016/j.susc.2024.122591","url":null,"abstract":"<div><p>Based on the first principles, we have calculated the influence of the applied electric field and doped X (X = N, P, As, Sb) atoms on the optoelectronic properties and phonon dispersion of the monolayer 2D material SnSe<sub>2</sub>. The calculation results show that intrinsic SnSe<sub>2</sub> is a semiconductor with a band gap value of 0.884 eV. The doping of X atoms improves the energy band tunability of the monolayer SnSe<sub>2</sub> system and becomes more stable. The N-doped SnSe<sub>2</sub> system has the most stable structure and the best doping performance. When the electric field strength of 0.3 V/Å is applied on the surface of the N-doped system, the band gap of the system increases. The energy gap gradually decreases when the electric field strength continues to increase from 0.3 V/Å to 0.9 V/Å. At an applied electric field strength of 0.9 V/Å, the system changes from semiconductor to metallic properties. As far as the optical properties are concerned, the applied electric field increases the static refractive index of the system, the imaginary part of the photoconductivity increases, the energy loss function decreases, and the light absorption performance improves. The applied electric field successfully enhanced the optical properties of the SnSe<sub>2</sub> system. The applied electric field strength of 0.9 V/Å doped N system has the best optical properties. This provides a new way to explore the optoelectronic devices based on the SnSe<sub>2</sub> doped system.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142099370","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}
Surface SciencePub Date : 2024-08-25DOI: 10.1016/j.susc.2024.122590
{"title":"Understanding the morphology and chemical activity of model ZrOx/Au (111) catalysts for CO2 hydrogenation","authors":"","doi":"10.1016/j.susc.2024.122590","DOIUrl":"10.1016/j.susc.2024.122590","url":null,"abstract":"<div><p>In this study, the growth of ZrO<sub>x</sub> on Au (111) was investigated using scanning tunneling microscopy (STM) and synchrotron-based ambient pressure X-ray photoelectron spectroscopy (AP-XPS). Nanostructures of ZrO<sub>x</sub> (<em>x</em> = 1,2) at the sub-monolayer (≤ 0.3 ML) level were prepared by vapor depositing Zr metal onto Au (111) followed by oxidation with O<sub>2</sub> or CO<sub>2</sub>. At low coverages of the admetal (< 0.05 ML), the formed ZrO<sub>x</sub> nanostructures were dispersed randomly on the terraces and steps of the Au(111) substrate. Strong oxide-metal interactions prevented the formation of islands of zirconia. The ZrO<sub>x</sub> nanostructures displayed a reactivity towards CO<sub>2</sub> and H<sub>2</sub> not seen for bulk zirconia. C 1 s AP-XPS results indicated that CO<sub>2</sub> molecules adsorbed on Zr/ZrO<sub>x</sub>/Au(111) surfaces could undergo partial decomposition on Zr (CO<sub>2, gas</sub> → CO<sub>gas</sub> + O<sub>ads</sub>), or react with oxygen sites from ZrO<em><sub>x</sub></em> to yield carbonates (Zr-CO<sub>3, ads</sub>). After exposing ZrO<sub>2</sub>/Au (111) surfaces to 1:3 mixtures of CO<sub>2</sub>:H<sub>2</sub>, the formation of HCOO, CO<sub>3</sub>, and CH<sub>3</sub>O was detected in AP-XP spectra. These chemical species decomposed at temperatures in the range of 400‒600 K, making them possible reaction intermediates for methanol synthesis.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088475","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}
Surface SciencePub Date : 2024-08-24DOI: 10.1016/j.susc.2024.122589
{"title":"LEED-IV analyses of tellurium adsorbate structures on iridium and gold surfaces","authors":"","doi":"10.1016/j.susc.2024.122589","DOIUrl":"10.1016/j.susc.2024.122589","url":null,"abstract":"<div><p>The determination of the configuration of atomic adsorbates on clean metal surfaces has been a key issue in surface science 60 years ago and still is today. We demonstrate that despite the prevalence of combined scanning tunneling microscopy and density functional theory studies of adsorbate systems the pitfalls are plentiful calling for accurate, reliable structure analyses that can be delivered by diffraction methods. We analyze and compare the ordered phases of Te on Ir(111), Ir(100), and Au(100) demonstrating the accuracy, the in-depth information and physical insight that can nowadays be obtained by quantitative low-energy electron diffraction structural analyses.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824001407/pdfft?md5=5d2e604f0131a149fd704b2f9ee5a739&pid=1-s2.0-S0039602824001407-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142083099","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}
Surface SciencePub Date : 2024-08-23DOI: 10.1016/j.susc.2024.122582
{"title":"Classification of adsorbates in scanning tunneling microscopy images of Fe3O4(111) surfaces exposed to water and carbon monoxide","authors":"","doi":"10.1016/j.susc.2024.122582","DOIUrl":"10.1016/j.susc.2024.122582","url":null,"abstract":"<div><p>Understanding the structure of catalyst surfaces with adsorbed molecules is key to improving catalyst design. Scanning tunneling microscopy (STM) allows the observation of adsorption states and sites and provides insights into diffusion and desorption processes; however, the presence of multiple types of molecules on the surface presents challenges such as the identification of species and verification of reaction progress, particularly at room temperature or higher. In this study, we develop a protocol for the height classification analysis of STM images using the Watershed algorithm. This method is applied to a system involving the co-adsorption of H<sub>2</sub>O and CO on the Fe<sub>3</sub>O<sub>4</sub>(111) surface, which represents the beginning of the water-gas shift reaction. Water molecules and dissociated OH species were identified in STM images of the Fe<sub>3</sub>O<sub>4</sub>(111) surface following the adsorption of water. Furthermore, gradual changes in the types of surface species were observed upon exposure of the surface to CO, indicating reaction progression. Our observations suggest that CO may react with molecular water rather than with dissociated OH on Fe sites. Despite its simplicity, the height classification analysis effectively identifies changes in the adsorbates on the catalyst surface. This method can be extended to other catalyst surfaces with adsorbed gasses.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S003960282400133X/pdfft?md5=a521c86ee1346871851784985be86359&pid=1-s2.0-S003960282400133X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142088441","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}
Surface SciencePub Date : 2024-08-22DOI: 10.1016/j.susc.2024.122580
{"title":"H2O-based atomic layer deposition mechanism of aluminum oxide using trimethylaluminum","authors":"","doi":"10.1016/j.susc.2024.122580","DOIUrl":"10.1016/j.susc.2024.122580","url":null,"abstract":"<div><p>As a nanofabrication technology, atomic layer deposition (ALD) has been widely used in the fields of displays, microelectronics, nanotechnology, catalysis, energy and coatings. It demonstrates excellent conformality, large-area uniformity and precise control of the sub-monolayer film. Al<sub>2</sub>O<sub>3</sub> ALD using trimethylaluminum (TMA) and water (H<sub>2</sub>O) as precursors is the most ideal ALD model system. In this work, the reactions of TMA and H<sub>2</sub>O with the surface have been investigated using density functional theory (DFT) calculations in order to obtain more information on the reaction mechanism of the complicated H<sub>2</sub>O-based ALD of Al<sub>2</sub>O<sub>3</sub>. In the TMA reaction, the methyl ligands can be eliminated and new Al-O bonds can be formed via ligand exchange reactions. In the H<sub>2</sub>O reaction, the methyl ligand on the surface can be further eliminated and new Al<img>O bonds can be formed. Meanwhile, the coupling reactions between the surface methyl and hydroxyl groups can further form new Al<img>O bonds and release CH<sub>4</sub> or H<sub>2</sub>O to densify the Al<sub>2</sub>O<sub>3</sub> film. These complicated reaction mechanisms of Al<sub>2</sub>O<sub>3</sub> H<sub>2</sub>O-based ALD can provide theoretical guidance for the precursor design and ALD growth of other oxides and aluminum-based compounds.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142057961","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}
Surface SciencePub Date : 2024-08-22DOI: 10.1016/j.susc.2024.122579
{"title":"Reduction of a two-dimensional crystalline MoO3 monolayer","authors":"","doi":"10.1016/j.susc.2024.122579","DOIUrl":"10.1016/j.susc.2024.122579","url":null,"abstract":"<div><p>The atomic structure of MoO<sub>x</sub> films formed upon a gradual thermal reduction of an ordered MoO<sub>3</sub> monolayer on the Pd(100) substrate was explored via surface science characterization techniques and density functional theory (DFT) calculations. Two main reduction stages were identified. First, the initial oxygen excess was gradually eliminated by altering the domain boundary length, orientation, and atomic structure. The films nevertheless remained O-rich, with numerous terminal oxygen atoms (formation of Mo<img>O groups), and an elevated work function. Second, multiple ordered O-lean phases were formed, characterized by either very few or no terminal oxygen atoms, and a much smaller surface work function. According to calculations, the positive charging of the Pd substrate stabilizes the oxygen excess during the first stage, but during the second reduction stage, the substrate becomes negatively charged, stabilizing enhanced cation oxidation states. On their basis, the mechanisms underlying the oxygen release from the initial c(2 × 2) domains were disclosed. The experiments showed that the film reduction is perfectly reversible, which highlights the very promising properties of the MoO<sub>3</sub>/Pd system for heterogeneous catalysis.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824001304/pdfft?md5=1525d168946b789b4b9dc648b293aa1e&pid=1-s2.0-S0039602824001304-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142049369","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}
Surface SciencePub Date : 2024-08-20DOI: 10.1016/j.susc.2024.122577
{"title":"Adsorption behavior of Cl2 on TiC0.89O0.11(001) surface based on the first principle calculation","authors":"","doi":"10.1016/j.susc.2024.122577","DOIUrl":"10.1016/j.susc.2024.122577","url":null,"abstract":"<div><p>Based on the first-principles ab initio calculation method of density functional theory (DFT), the adsorption models of Cl<sub>2</sub> molecules on both the TiC<sub>0.89</sub>O<sub>0.11</sub>(001) intact surface and the carbon vacancy surface were established, followed by calculations and analysis of the adsorption structures, adsorption energy, differential charge density, and density of states (DOS). The results demonstrate that the adsorption process of Cl<sub>2</sub> molecules on the TiC<sub>0.89</sub>O<sub>0.11</sub>(001) surface involves chemical adsorption, with a higher likelihood of dissociation into Cl atoms during adsorption. These dissociated Cl atoms can potentially interact with surface Ti and/or C atoms to form Ti-Cl bonds, C-Cl bonds, Ti-Cl-C bonds, and Ti-Cl-Ti bonds. Simultaneously, the stability of the adsorbed structure is influenced by both the bonding conditions between Cl atoms and surface atoms and the position of Cl atom adsorption (e.g., whether it is located above the vacancy C). Following adsorption, there is a weakening in the bonding strength of Ti-C or Ti-O bonds on the TiC<sub>0.89</sub>O<sub>0.11</sub>(001) surface. During the adsorption process, Cl atoms can either act as electron donors or acceptors. When the Ti-Cl bond structure is formed, Cl atoms function as electron acceptors; however, when the C-Cl bond structure is established, Cl atoms predominantly act as electron donors. Surface Ti atoms act as electron donors while surface C and O atoms function as electron acceptors. Additionally, the presence of surface carbon vacancy enhances the interaction between Cl and Ti atoms, weakens the interaction between Cl and C atoms, and attenuates the interaction between C, O, and Ti atoms in the structure. And it can augment the electron acquisition by Cl<sub>2</sub> molecules upon adsorption, reduce the adsorption energy, and promote greater stability in the adsorption structure. All the effects contribute to facilitating TiCl<sub>4</sub> formation.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0039602824001286/pdfft?md5=52d5402f1dbddadac167e3e94a29a84d&pid=1-s2.0-S0039602824001286-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142083098","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}
Surface SciencePub Date : 2024-08-17DOI: 10.1016/j.susc.2024.122578
{"title":"Insights into the interaction of nitrobenzene and the Ag(111) surface: A DFT study","authors":"","doi":"10.1016/j.susc.2024.122578","DOIUrl":"10.1016/j.susc.2024.122578","url":null,"abstract":"<div><p>This study explores the potential of nitrobenzene as an anolyte material for nonaqueous redox flow batteries (RFBs) by theoretically examining its low-coverage adsorption behavior on neutral and charged Ag(111) model electrode surfaces. At the low coverage limit, DFT calculations show a preference for nitrobenzene to adsorb parallel to the surface, with the benzene ring and nitro group centered over HCP sites. Interactions between nitrobenzene and the surface were analyzed using induced charge density analysis, Bader charge analysis, and projected density of states (PDOS). It was found that nitrobenzene adsorbs primarily through van der Waals interactions with the surface. As nitrobenzene accumulates negative charge, the strength of adsorption diminishes. Understanding the electrode-electrolyte interface is crucial for enhancing RFB electrochemical performance, and this study sheds light on nitrobenzene's interaction with a model Ag electrode.</p></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142058045","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}