Surface Science最新文献

{"title":"Exploring the atomic-scale dynamics of Fe3O4(001) at catalytically relevant temperatures using FastSTM","authors":"Johanna Reich ,&nbsp;Sebastian Kaiser ,&nbsp;Alexander Bourgund ,&nbsp;Matthias Krinninger ,&nbsp;Ueli Heiz ,&nbsp;Friedrich Esch ,&nbsp;Barbara A.J. Lechner","doi":"10.1016/j.susc.2024.122634","DOIUrl":"10.1016/j.susc.2024.122634","url":null,"abstract":"<div><div>Surfaces and interfaces of functional nanoscale materials are typically highly dynamic when employed at elevated temperatures. Both, lateral surface and vertical bulk exchange diffusion processes set in, which can be relevant for applications such as heterogeneous catalysis. Time-resolved scanning tunneling microscopy (STM) is being pushed to ever faster measurement modes to follow such dynamic phenomena in situ. Here, we present FastSTM movies monitoring a range of atomic-scale dynamics of a prototypical reducible oxide catalyst support, Fe₃O₄(001), at elevated temperatures. Antiphase domain boundaries between two domains of the reconstructed surface exhibit local mobility from around 350 K, while Fe-rich point defects, in a stable equilibrium with the bulk, appear to diffuse in a peculiar zigzag pattern above 500 K. Finally, exploiting the diffusivity of Fe interstitials, we follow the propagation of step edges in the topmost atomic layer of the Fe₃O₄(001) surface in an oxygen atmosphere.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"752 ","pages":"Article 122634"},"PeriodicalIF":2.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592996","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":"Growth and electronic structure of the nodal line semimetal in monolayer Cu2Si on Cu(111)","authors":"Jinfeng Xu ,&nbsp;Chen Liu ,&nbsp;Yuxuan Guo ,&nbsp;Guikai Zhang ,&nbsp;Kun Liu ,&nbsp;Haijie Qian ,&nbsp;Kaiqi Nie ,&nbsp;Zhenyu Wang ,&nbsp;Jiaou Wang","doi":"10.1016/j.susc.2024.122632","DOIUrl":"10.1016/j.susc.2024.122632","url":null,"abstract":"<div><div>Cu₂Si, a single-layer two-dimensional material with a honeycomb structure, has been proposed to have Dirac nodal line fermions. In this study, the synchrotron radiation X-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and angle-resolved photoemission spectroscopy (SR-XPS, SR-UPS, and SR-ARPES) techniques were used to investigate the dynamic process of in situ deposition of single-layer Cu₂Si on a Cu(111) crystal surface via molecular beam epitaxy (MBE). Cu₂Si existed as a monolayer (ML) alloy, and there were competing mechanisms of distinct chemical states of silicon in different growth periods, according to a detailed examination of the experimental SR-XPS and SR-UPS spectra. Additionally, a weak interaction between the Cu₂Si ML and Cu(111) was demonstrated via SR-ARPES and first-principles computations. The unique electronic structure of the Cu₂Si ML was not destroyed by either this weak interaction or the disordered silicon produced on the surface during the growth process. The study of the Cu₂Si growth kinetics provides a guarantee and a basis for the future exploration of the exotic properties of Cu₂Si.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"752 ","pages":"Article 122632"},"PeriodicalIF":2.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553519","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":"Step-by-step silicon carbide graphitisation process study in terms of time and temperature parameters","authors":"K. Idczak ,&nbsp;S. Owczarek ,&nbsp;A. Trembułowicz ,&nbsp;B. Rusin","doi":"10.1016/j.susc.2024.122630","DOIUrl":"10.1016/j.susc.2024.122630","url":null,"abstract":"<div><div>This work investigates the temperature and time as key parameters for graphene formation on the silicon carbide surface during the high thermal decomposition process. Measurements were performed using various experimental techniques under ultra-high vacuum conditions. The graphitisation process was divided into various stages, after which the surface chemical composition and atomic structures were analysed in detail. It has been shown that despite the known theory of graphitisation mechanism and initial condition for occurrence of this process, the application of different temperatures and heating times affect the quality and quantity of formed graphene layers. Applying a temperature too low or annealing the sample for a too short time led to an inefficient silicon sublimation process. On the other hand, too high temperature during flashing modifies the visibility of surface structures, which may be crucial for other investigations and potential applications of such systems.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122630"},"PeriodicalIF":2.1,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532114","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":"Imaging on surfaces with vibrational sum frequency generation microscopy","authors":"Sarah M. Ortiz,&nbsp;Steven Baldelli","doi":"10.1016/j.susc.2024.122627","DOIUrl":"10.1016/j.susc.2024.122627","url":null,"abstract":"<div><div>Nonlinear spectroscopy has been a valuable technique for probing surfaces for many decades. Still, in the recent past, nonlinear spectroscopy has become a useful tool for imaging monolayers on surfaces. This technique of nonlinear microscopy, more specifically sum frequency generation microscopy, provides both spectral and spatial information with varying resolution, allowing for the surface activity to be monitored and imaged. The following paper highlights the history, theory, and range of experimental advantages sum frequency generation imaging provides, focusing on specific experiments that put those advantages on display.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122627"},"PeriodicalIF":2.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532021","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":"In air STM observation of Au(111) surface disturbance including Au magic fingers as modified by solvent choice","authors":"Dillon Dodge,&nbsp;Rowan Dirks,&nbsp;Lauren F. Hornbrook,&nbsp;Nazila Hamidi,&nbsp;Erin V. Iski","doi":"10.1016/j.susc.2024.122629","DOIUrl":"10.1016/j.susc.2024.122629","url":null,"abstract":"<div><div>A widely studied surface phenomena on Au(111) is the formation of Au magic fingers, which were first discovered nearly 20 years ago. A variety of experimental conditions have been used to observe the formation of Au magic fingers with a slight preference to ultra-high vacuum and low temperature studies. With the advances in scanning probe techniques, it is possible to study these unique structures under more relevant conditions including in air and at room temperature. After exposure to a 0.1 M solvent solution, Au(111) displayed three types of surface disturbances, including the formation of Au magic fingers, based on the identity of the solvent. The type of disturbance was dependent on the solvent molecule's characteristics, specifically its total charge and its electrolytic behavior in aqueous environments. The mechanism of disturbance relied on a strong tip-surface interaction and the mass transport of Au atoms, which was modified by the solvent selected. Overall, the ability to form organized nanostructures, like Au magic fingers, in a repeated way in environments outside of UHV and without a protective liquid layer increases the utility of these structures into a wider array of fields and applied areas.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122629"},"PeriodicalIF":2.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532019","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":"Computational insight into the selectivity of γ-valerolactone hydrodeoxygenation over Rh(111) and Ru(0001)","authors":"Minttu M. Kauppinen ,&nbsp;Ewa N. Słapa ,&nbsp;José Luis González Escobedo ,&nbsp;Riikka L. Puurunen ,&nbsp;Karoliina Honkala","doi":"10.1016/j.susc.2024.122624","DOIUrl":"10.1016/j.susc.2024.122624","url":null,"abstract":"<div><div>The observed difference in the selectivity towards alkane, ketone, and alcohol hydrodeoxygenation products over Ru and Rh catalysts is explored using a combination of density functional theory and microkinetics. Using <span><math><mi>γ</mi></math></span>-valerolactone as a model compound, we investigate the reaction mechanism in order to identify selectivity determining species. The effect of the coadsorbed water molecule as well as the higher adsorbate surface coverage on reaction barriers and energies is explored as well. The performed calculations suggest that the desired alkane product is formed from a ketone intermediate on Ru, and through both ketone and alcohol on Rh, although the selectivity towards alkane on Rh is much lower than on Ru.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122624"},"PeriodicalIF":2.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532023","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":"Surface science studies on electron-induced reactions of NH3 and their perspectives for enhancing nanofabrication processes","authors":"Hannah Boeckers ,&nbsp;Markus Rohdenburg ,&nbsp;Petra Swiderek","doi":"10.1016/j.susc.2024.122628","DOIUrl":"10.1016/j.susc.2024.122628","url":null,"abstract":"<div><div>Ammonia (NH₃) dissociates efficiently when it interacts with an electron beam. This applies not only to single electron-NH₃ collisions in the gas phase but also to electron irradiation of NH₃ adsorbed on surfaces. The dissociation products include atomic hydrogen which can act as a reducing agent or NH₂ radicals that can bind to suitable surfaces or to adsorbed molecules. This chemistry can be exploited in nanofabrication processes that use electron beams for deposition, etching, or modification of materials. This review describes the current state of insight regarding electron-induced reactions of NH₃ adsorbed on surfaces and outlines approaches to the use of these reactions for enhancing electron beam induced nanofabrication processes. First, an overview of surface science studies on electron-induced reactions of NH₃ adsorbed on single crystal surfaces is given. This is followed by a summary of studies on the use of NH₃ for improving the purity of deposits prepared by electron beam induced deposition (EBID) and on the prospects of NH₃ to suppress unwanted thermal surface chemistry during EBID. Finally, we discuss electron-induced reactions of NH₃ that are fundamental to the modification of carbonaceous nanomaterials as well as potential application scenarios such as the functionalization of self-assembled monolayers and humidity sensing.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122628"},"PeriodicalIF":2.1,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532024","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":"Electrochemical surface science: Self-assembly of Porphyrin molecules at single crystal metal electrodes","authors":"Tomasz Kosmala ,&nbsp;Phan Thanh Hai ,&nbsp;Nguyen Thi Minh Hai ,&nbsp;Klaus Wandelt","doi":"10.1016/j.susc.2024.122626","DOIUrl":"10.1016/j.susc.2024.122626","url":null,"abstract":"<div><div>A detailed understanding of properties and processes at surfaces and interfaces requires at least two types of most basic information, <em>chemical composition and –distribution</em> as well as <em>structure.</em> While surface science in ultrahigh vacuum is blessed with a plethora of high sensitivity and highest spatial and temporal resolution due to the free accessibility of the surfaces by any kind of probe beams, investigations of solid surfaces under ambient conditions, i.e. in contact with gases or liquids, were for a long time restricted to the use of integral photon-based reflection-, absorption-, emission-, and diffraction methods. This “methodological gap” between UHV surface science and environmental interface research became immediately, at least partially, closed after the realization of the scanning tunneling microscope (STM) and following variants of proximity probes (SPM). The full applicability of this class of methods also under ambient conditions opened the door to structure information of solid-liquid interfaces of comparable resolution as in UHV at room temperature, a “quantum leap” for the understanding of e.g. interfacial electrochemistry. This, in turn, highlighted the need of reliable determination of the chemical composition and distribution at solid-liquid interfaces and pushed the development of in situ X-ray photoelectron spectroscopy (XPS).</div><div>The availability of both techniques, in situ SPM and in situ XPS closes the former methodological gap between the research in UHV and under ambient conditions. In particular, interfacial electrochemistry, being primarily interested in chemical processes at electrode/electrolyte interfaces benefits decisively of this development.</div><div>In this article, as an example, we present systematic in situ STM measurements and results on the interactions and self-assembly of porphyrins at anion modified metal/electrolyte interfaces, an important class of molecules for the functionalization of surfaces for various applications. Atomically and sub-molecularly resolved potentiostatic and potentiodynamic in situ STM images of such molecular layers are nowadays standard and wait for an in-depth theoretical analysis.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122626"},"PeriodicalIF":2.1,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532022","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":"Characterizing the surface compositions of supported bimetallic PtSn clusters: Effects of cluster-support interactions and surface adsorbates","authors":"Fangliang Li ,&nbsp;Ali S. Ahsen ,&nbsp;Salai C. Ammal ,&nbsp;Mengxiong Qiao ,&nbsp;Thathsara D. Maddumapatabandi ,&nbsp;Sumit Beniwal ,&nbsp;Andreas Heyden ,&nbsp;Donna A. Chen","doi":"10.1016/j.susc.2024.122623","DOIUrl":"10.1016/j.susc.2024.122623","url":null,"abstract":"<div><div>PtSn bimetallic clusters on TiO₂(110) and highly oriented pyrolytic graphite (HOPG) surfaces have been characterized by scanning tunneling microscopy, low energy ion scattering (LEIS), X-ray photoelectron spectroscopy, and temperature programmed desorption (TPD); density functional theory (DFT) calculations have also been performed to better understand adsorption of CO and D₂ on the PtSn surfaces. On TiO₂ at coverages of 2 ML of Pt and 2 ML of Sn, exclusively bimetallic clusters are formed for both orders of deposition because clusters of the first metal completely cover the surface such that all atoms of the second metal are incorporated into the existing clusters. In contrast, on HOPG, the high mobility and weak cluster-support interactions on HOPG result in much larger 2 ML monometallic clusters (∼30 Å high) that do not completely cover the surface, and deposition of the second metal produces larger clusters as well as smaller ones. Despite the difference in cluster morphologies for the different orders of deposition and supports, the LEIS experiments demonstrate that in all cases, the PtSn clusters are rich in Sn at the surface, as expected based on the lower surface free energy for Sn compared to Pt. Furthermore, the +0.2 eV shift in the Sn(3d_5/2) binding energy observed on all surfaces in the presence of Pt is consistent with PtSn alloy formation. Deposition of 2 ML of Sn on TiO₂ produces two-dimensional clusters with oxidation of Sn and reduction of titania at the cluster-support interface, but addition of Pt to the Sn clusters causes Sn to diffuse away from this interface, leaving Sn in the metallic state. TPD experiments on 2 ML Pt/TiO₂ with increasing coverages of Sn show that the number of adsorption sites for D₂ sharply decreases to nearly zero at 0.5 ML, while CO adsorption decreases to zero only at much higher Sn coverages of 2 ML. DFT studies for Sn modified Pt surfaces and bulk structures demonstrate that for CO adsorption at low Sn coverages (≤0.25 ML), the strong Pt-CO interactions induce diffusion of Pt to the cluster surface and the formation of a bulk Pt₃Sn alloy, whereas D₂ adsorption does not lead to interactions with the Pt surface that are strong enough to induce alloy formation. A single Sn adatom prevents D₂ adsorption on four neighboring Pt atoms via site-blocking and the donation of electron density to Pt.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122623"},"PeriodicalIF":2.1,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444599","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":"Alloying effects on the reactivity of Pd are ensemble dominated","authors":"Michael Bowker","doi":"10.1016/j.susc.2024.122620","DOIUrl":"10.1016/j.susc.2024.122620","url":null,"abstract":"<div><div>In this paper the geometric (“ensemble”) and electronic (“ligand”) effects of alloying on surface reactivity and catalysis are considered. The effect of alloying on the behaviour of Pd, both in single crystal form, and as a nanoparticulate catalyst is discussed. The first case concerns Pd alloyed with Cu, and here the reactivity with formic acid and ethanol is modified by the presence of Cu. However, both Cu and Pd maintain their elemental integrity for the reactions, and it is shown that the main alloying effect is one of dilution of Pd atoms, rather than by global electronic factors such as d-band shifting and filling. Similarly, when Pd is alloyed with Au, then the adsorption characteristics (sticking probability and uptake) for CO, O₂, ethene and acetaldehyde are dominated by changes in the surface arrangement of the two atoms. Au mainly acts as an adsorption blocker, but to different degrees depending upon the nature of the adsorbing molecule and its demand for particular ensemble sizes. Finally, nanoparticulate Pd is considered, and the effect of alloying on high pressure methanol synthesis from CO₂ and H₂ is outlined. Pd on its own is not very selective, instead it mainly produces CO and methane. However, by supporting on oxides such as ZnO, Ga₂O₃ and In₂O₃ and by reducing in hydrogen, the Pd forms alloys, which then results in high selectivity to methanol. Again, this is ascribed to the dilution of the Pd ensembles at the surface, which are the cause of methane production.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"751 ","pages":"Article 122620"},"PeriodicalIF":2.1,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532115","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}