Pub Date : 2025-12-31DOI: 10.1016/j.susc.2025.122929
Ashutosh Mishra, J. Will Medlin
The roles of surface defects and oxygen vacancies on transition metal oxide surfaces have been extensively studied in the context of tuning catalytic properties. To gain further insights into recent reports of aldol condensation catalysis on molybdenum oxides, we investigated condensation of acetaldehyde on oxidized and sputtered Mo(100) using surface science probes. X-ray photoelectron spectroscopy (XPS) analysis reveals that sputtering promotes the formation of MoOx suboxides (0 < x < 2) and effectively generates oxygen vacancies. Temperature-programmed desorption and high-resolution electron energy loss spectroscopy demonstrate that the oxidized Mo(100) surface facilitated aldol coupling reactions, likely through surface-bound enolate intermediates, leading to crotonaldehyde desorption. The sputtered (reduced) surfaces enhance interaction of surface-bound species and favor reductive coupling pathways to alkenes. Reductive coupling of acetaldehyde proceeds through pinacolate intermediates to form unsaturated olefins. These findings highlight the critical role of surface oxygen vacancies and metal oxidation state in directing selectivity and kinetics for oxygenate coupling reactions on molybdenum-based catalysts.
表面缺陷和氧空位在过渡金属氧化物表面的作用在调节催化性能方面得到了广泛的研究。为了进一步了解最近报道的醛醇在钼氧化物上的缩合催化作用，我们使用表面科学探针研究了乙醛在氧化和溅射Mo（100）上的缩合。x射线光电子能谱（XPS）分析表明，溅射促进MoOx亚氧化物（0 < x < 2）的形成，有效地产生氧空位。程序升温解吸和高分辨率电子能量损失谱表明，氧化的Mo（100）表面促进了醛醇偶联反应，可能通过表面结合的烯醇酸中间体，导致了巴丁醛的解吸。溅射（还原）表面增强了表面结合物质的相互作用，有利于还原偶联途径生成烯烃。乙醛的还原偶联通过松酸酯中间体形成不饱和烯烃。这些发现强调了表面氧空位和金属氧化态在指导钼基催化剂上氧偶联反应的选择性和动力学中的关键作用。
{"title":"Aldol condensation of acetaldehyde on oxidized and sputtered Mo(100) surfaces","authors":"Ashutosh Mishra, J. Will Medlin","doi":"10.1016/j.susc.2025.122929","DOIUrl":"10.1016/j.susc.2025.122929","url":null,"abstract":"<div><div>The roles of surface defects and oxygen vacancies on transition metal oxide surfaces have been extensively studied in the context of tuning catalytic properties. To gain further insights into recent reports of aldol condensation catalysis on molybdenum oxides, we investigated condensation of acetaldehyde on oxidized and sputtered Mo(100) using surface science probes. X-ray photoelectron spectroscopy (XPS) analysis reveals that sputtering promotes the formation of MoO<sub>x</sub> suboxides (0 < <em>x</em> < 2) and effectively generates oxygen vacancies. Temperature-programmed desorption and high-resolution electron energy loss spectroscopy demonstrate that the oxidized Mo(100) surface facilitated aldol coupling reactions, likely through surface-bound enolate intermediates, leading to crotonaldehyde desorption. The sputtered (reduced) surfaces enhance interaction of surface-bound species and favor reductive coupling pathways to alkenes. Reductive coupling of acetaldehyde proceeds through pinacolate intermediates to form unsaturated olefins. These findings highlight the critical role of surface oxygen vacancies and metal oxidation state in directing selectivity and kinetics for oxygenate coupling reactions on molybdenum-based catalysts.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"767 ","pages":"Article 122929"},"PeriodicalIF":1.8,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927567","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}
Pub Date : 2025-12-30DOI: 10.1016/j.susc.2025.122928
Shigekazu Nagai, Eiji Oyaizu, Tatsuo Iwata
Field-assisted chemical etching of tungsten (W) demonstrates significantly greater efficacy in H2O than in O2. In this study, in-situ atom-probe mass spectrometry combined with field-ion microscopy (FIM) was employed to identify ion species as a function of the applied field strength. Under 1 × 10−3 Pa O2, FIM images transitioned from a clean W<011> surface to a ring-encircled pattern over approximately 255 min. In contrast, under 1 × 10−4 Pa of H2O, similar morphological evolution and nano-protrusion formation were completed within 116 min, despite the lower pressure, indicating accelerated etching of tungsten in H₂O. Atom-probe spectra revealed a field-dependent transition: at higher fields, W³⁺ is predominant, whereas at ≤ 28 V nm−1, the intensities of WO2⁺/WO2²⁺/WO3²⁺ increased notably at 22 V nm−1 in H₂O. Furthermore, when compared at equal pressures, the etch rate in H2O was two orders of magnitude higher than that in O2, highlighting its processing advantage. These findings establish a field-dependent and species-specific mechanism underlying the accelerated etching behavior in H2O and offer practical guidance for fabricating size-controlled W nano-protrusions for high-brightness electron and ion emitter applications.
磁场辅助化学蚀刻钨(W)在H2O中的效果明显优于在O2中的效果。在这项研究中，原位原子探针质谱结合场离子显微镜（FIM）来鉴定离子种类作为应用场强的函数。在1 × 10−3 Pa O2下，FIM图像在大约255分钟内从干净的W<；011>；表面转变为环状图案。相比之下，在1 × 10−4 Pa的H2O条件下，尽管压力较低，但类似的形态演变和纳米突起的形成在116 min内完成，这表明钨在H2O中的蚀刻加速。原子探针光谱显示了场相关的跃迁：在更高的场下，W³⁺占优势，而在≤28 V nm - 1时，WO2 + /WO2 + /WO3 +在22 V nm - 1的H₂O中强度显著增加。此外，当在相同压力下进行比较时，在H2O中的蚀刻速率比在O2中的蚀刻速率高两个数量级，突出了其加工优势。这些发现建立了在H2O中加速蚀刻行为的场依赖和物种特异性机制，并为制造用于高亮度电子和离子发射器的尺寸控制的W纳米突出物提供了实用指导。
{"title":"In-situ atom probe analysis of field-assisted etching of tungsten in O2 and H2O","authors":"Shigekazu Nagai, Eiji Oyaizu, Tatsuo Iwata","doi":"10.1016/j.susc.2025.122928","DOIUrl":"10.1016/j.susc.2025.122928","url":null,"abstract":"<div><div>Field-assisted chemical etching of tungsten (W) demonstrates significantly greater efficacy in H<sub>2</sub>O than in O<sub>2</sub>. In this study, in-situ atom-probe mass spectrometry combined with field-ion microscopy (FIM) was employed to identify ion species as a function of the applied field strength. Under 1 × 10<sup>−3</sup> Pa O<sub>2</sub>, FIM images transitioned from a clean W<011> surface to a ring-encircled pattern over approximately 255 min. In contrast, under 1 × 10<sup>−4</sup> Pa of H<sub>2</sub>O, similar morphological evolution and nano-protrusion formation were completed within 116 min, despite the lower pressure, indicating accelerated etching of tungsten in H₂O. Atom-probe spectra revealed a field-dependent transition: at higher fields, W³⁺ is predominant, whereas at ≤ 28 V nm<sup>−1</sup>, the intensities of WO<sub>2</sub>⁺/WO<sub>2</sub>²⁺/WO<sub>3</sub>²⁺ increased notably at 22 V nm<sup>−1</sup> in H₂O. Furthermore, when compared at equal pressures, the etch rate in H<sub>2</sub>O was two orders of magnitude higher than that in O<sub>2</sub>, highlighting its processing advantage. These findings establish a field-dependent and species-specific mechanism underlying the accelerated etching behavior in H<sub>2</sub>O and offer practical guidance for fabricating size-controlled W nano-protrusions for high-brightness electron and ion emitter applications.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"767 ","pages":"Article 122928"},"PeriodicalIF":1.8,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927566","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}
Pub Date : 2025-12-27DOI: 10.1016/j.susc.2025.122927
N. Braud , H.J. Wallander , L. Buß , M. Löfstrand , J. Blomqvist , C. Berschauer , A. Morales Rodriguez , P.M. Kofoed , A. Resta , J.-O. Krisponeit , T. Schmidt , E. Lundgren , J.I. Flege , J. Falta , L.R. Merte
Here we report an investigation of ultrathin tin oxide films on PtSn(111) using low-energy electron microscopy (LEEM), microspot low-energy electron diffraction (-LEED), scanning tunneling microscopy (STM), surface X-ray diffraction (SXRD), and high-resolution X-ray photoelectron spectroscopy (XPS). Oxidation at 390–410 produces triangular, two-dimensional oxide islands that nucleate rapidly and exhibit self-limited lateral growth, attributed to limited Sn diffusion from the subsurface of the crystal. -LEED shows that the initially formed Sn oxide is subsequently converted to a more oxygen-rich “stripe” phase. At 630 , enhanced Sn mobility enables a closed film. The phase is shown to consist of a Sn lattice modulated by 1D stripe defects with spacings of –6 atomic rows; LEED and SXRD measurements show diffraction features corresponding to this striped superstructure. The two oxides can be distinguished in XPS by their O 1s lineshapes: the phase shows a clear doublet attributable to distinct O species, whereas the phase exhibits a broader envelope consistent with a distribution of O coordination environments. The Sn 3d spectra are similar for both phases, reflecting closely related Sn bonding motifs. The spectra are consistent with those of previous near-ambient-pressure XPS measurements, suggesting that the surface oxides forming under CO oxidation conditions are similar to those studied here.
{"title":"Growth, structure, and morphology of ultra-thin tin oxide phases forming on Pt3Sn(111) single crystals upon exposure to oxygen","authors":"N. Braud , H.J. Wallander , L. Buß , M. Löfstrand , J. Blomqvist , C. Berschauer , A. Morales Rodriguez , P.M. Kofoed , A. Resta , J.-O. Krisponeit , T. Schmidt , E. Lundgren , J.I. Flege , J. Falta , L.R. Merte","doi":"10.1016/j.susc.2025.122927","DOIUrl":"10.1016/j.susc.2025.122927","url":null,"abstract":"<div><div>Here we report an investigation of ultrathin tin oxide films on Pt<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>Sn(111) using low-energy electron microscopy (LEEM), microspot low-energy electron diffraction (<span><math><mi>μ</mi></math></span>-LEED), scanning tunneling microscopy (STM), surface X-ray diffraction (SXRD), and high-resolution X-ray photoelectron spectroscopy (XPS). Oxidation at <span><math><mo>∼</mo></math></span>390–410 <span><math><mrow><mo>°</mo><mi>C</mi></mrow></math></span> produces triangular, two-dimensional oxide islands that nucleate rapidly and exhibit self-limited lateral growth, attributed to limited Sn diffusion from the subsurface of the crystal. <span><math><mi>μ</mi></math></span>-LEED shows that the initially formed <span><math><mrow><mo>(</mo><mn>4</mn><mo>×</mo><mn>4</mn><mo>)</mo></mrow></math></span> Sn oxide is subsequently converted to a more oxygen-rich <span><math><mrow><mo>(</mo><mn>2</mn><mo>×</mo><mn>2</mn><mi>n</mi><mo>)</mo></mrow></math></span> “stripe” phase. At 630 <span><math><mrow><mo>°</mo><mi>C</mi></mrow></math></span>, enhanced Sn mobility enables a closed <span><math><mrow><mo>(</mo><mn>4</mn><mo>×</mo><mn>4</mn><mo>)</mo></mrow></math></span> film. The <span><math><mrow><mo>(</mo><mn>2</mn><mo>×</mo><mn>2</mn><mi>n</mi><mo>)</mo></mrow></math></span> phase is shown to consist of a <span><math><mrow><mo>(</mo><mn>2</mn><mo>×</mo><mn>2</mn><mo>)</mo></mrow></math></span> Sn lattice modulated by 1D stripe defects with spacings of <span><math><mrow><mi>n</mi><mo>=</mo><mn>4</mn></mrow></math></span>–6 atomic rows; LEED and SXRD measurements show diffraction features corresponding to this striped superstructure. The two oxides can be distinguished in XPS by their O 1s lineshapes: the <span><math><mrow><mo>(</mo><mn>4</mn><mo>×</mo><mn>4</mn><mo>)</mo></mrow></math></span> phase shows a clear doublet attributable to distinct O species, whereas the <span><math><mrow><mo>(</mo><mn>2</mn><mo>×</mo><mn>2</mn><mi>n</mi><mo>)</mo></mrow></math></span> phase exhibits a broader envelope consistent with a distribution of O coordination environments. The Sn 3d<span><math><msub><mrow></mrow><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow></msub></math></span> spectra are similar for both phases, reflecting closely related Sn bonding motifs. The spectra are consistent with those of previous near-ambient-pressure XPS measurements, suggesting that the surface oxides forming under CO oxidation conditions are similar to those studied here.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"767 ","pages":"Article 122927"},"PeriodicalIF":1.8,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927568","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}
In this paper, the adsorption properties of NO2 on W-modification ZnO, based on the synergistic effect of Wolframium (W) and Oxygen vacancy defects, has been investigated using density functional theory (DFT) calculations. The modulation of hypervalent transition metal W greatly changed the electronic structure of the crystal plane, which could promote the generation of oxygen vacancy defects on the crystal plane. Under the synergistic effect of W-doped and oxygen vacancies, the conductivity of the ZnO (002) could be effectively enhanced, that would mean the improvement of NO2 adsorption. Energy analysis shows that the adsorption energy is improved from the original -0.752 eV to -7.506 eV, a 9.98-fold enhancement. Mulliken charge population analysis shows that the charge transfer amount increased from -0.316 e to -0.941 e, which is 2.97 times higher. Theoretical calculations show that the sensitivity in adsorption of NO₂ can reach 18.626, which is about 24.4 times that of the intrinsic one. Moreover, the W-doped ZnO material exhibits superior adsorption selectivity for NO2 compared to other gases such as CO, CO2, H2, and NO, which can provide new ideas for the design of NO2 gas sensors with ultra-low concentrations.
{"title":"The synergistic effect of W-modification and oxygen vacancies on ZnO for detecting NO2: A DFT study","authors":"Ziyu Chen, Haojie Lv, Chunli Diao, Guanwei Jia, Cheng Gu","doi":"10.1016/j.susc.2025.122916","DOIUrl":"10.1016/j.susc.2025.122916","url":null,"abstract":"<div><div>In this paper, the adsorption properties of NO<sub>2</sub> on W-modification ZnO, based on the synergistic effect of Wolframium (W) and Oxygen vacancy defects, has been investigated using density functional theory (DFT) calculations. The modulation of hypervalent transition metal W greatly changed the electronic structure of the crystal plane, which could promote the generation of oxygen vacancy defects on the crystal plane. Under the synergistic effect of W-doped and oxygen vacancies, the conductivity of the ZnO (002) could be effectively enhanced, that would mean the improvement of NO<sub>2</sub> adsorption. Energy analysis shows that the adsorption energy is improved from the original -0.752 eV to -7.506 eV, a 9.98-fold enhancement. Mulliken charge population analysis shows that the charge transfer amount increased from -0.316 e to -0.941 e, which is 2.97 times higher. Theoretical calculations show that the sensitivity in adsorption of NO₂ can reach 18.626, which is about 24.4 times that of the intrinsic one. Moreover, the W-doped ZnO material exhibits superior adsorption selectivity for NO<sub>2</sub> compared to other gases such as CO, CO<sub>2</sub>, H<sub>2</sub>, and NO, which can provide new ideas for the design of NO<sub>2</sub> gas sensors with ultra-low concentrations.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"767 ","pages":"Article 122916"},"PeriodicalIF":1.8,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145842862","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}
This study extends the experimental work of Ismet Gelen et al. (2024) [Physica Status Solidi B 26, 2300,518], investigating the growth, morphology, and structure of MnxAu1−x films on Cu(001) and Ag(001) surfaces. We provide a theoretical analysis of these alloys on noble metal substrates, both fcc structures. Using firstprinciples density functional theory (DFT) with the generalized gradient approximation, we systematically examined the magnetic phases. Our findings reveal that the lowest-energy configuration on both substrates is ferromagnetic at lower Mn concentrations. Notably, Mn remains in a high-spin state in all cases, while the average magnetic moment diminishes with increasing Mn content.
本研究扩展了Ismet Gelen等人（2024）[physics Status Solidi B 26, 2300,518]的实验工作，研究了Cu（001）和Ag（001）表面上MnxAu1−x膜的生长、形态和结构。我们提供了这些合金在贵金属衬底上的理论分析，两者都是fcc结构。利用第一性原理密度泛函理论（DFT）和广义梯度近似，系统地研究了磁相。我们的研究结果表明，在低锰浓度下，两种底物上的最低能量构型都是铁磁性的。值得注意的是，在所有情况下，Mn都保持在高自旋态，而平均磁矩随着Mn含量的增加而减小。
{"title":"Mn high magnetic moments for surface ordered alloys of MnxAu1−x on Cu(001) and Ag(001): density functional calculations","authors":"J.U. Gallardo-Zazueta , S. Meza-Aguilar , J.J. Molina-Duarte , F.C. Delgado-Nieblas","doi":"10.1016/j.susc.2025.122917","DOIUrl":"10.1016/j.susc.2025.122917","url":null,"abstract":"<div><div>This study extends the experimental work of Ismet Gelen et al. (2024) [Physica Status Solidi B 26, 2300,518], investigating the growth, morphology, and structure of Mn<sub>x</sub>Au<sub>1−</sub><em><sub>x</sub></em> films on Cu(001) and Ag(001) surfaces. We provide a theoretical analysis of these alloys on noble metal substrates, both fcc structures. Using firstprinciples density functional theory (DFT) with the generalized gradient approximation, we systematically examined the magnetic phases. Our findings reveal that the lowest-energy configuration on both substrates is ferromagnetic at lower Mn concentrations. Notably, Mn remains in a high-spin state in all cases, while the average magnetic moment diminishes with increasing Mn content.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"767 ","pages":"Article 122917"},"PeriodicalIF":1.8,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885890","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}
This study aims to elucidate the regulation mechanism of elemental doping on the adsorption and migration behavior of Al atoms on TiN surfaces, providing a theoretical basis for optimizing the wettability and bonding properties at metal-ceramic interfaces. Density functional theory (DFT) based first-principles calculations were employed to systematically investigate the electronic structure and mechanical properties of bulk TiN, alongside the adsorption configurations and migration behavior of Al atoms on typical low-index TiN surfaces ((100), (110), (111)-N, (111)-Ti). The regulatory effects of dopants on migration barriers were also evaluated. Results indicate that bulk TiN exhibits metal-covalent hybrid bonding and anisotropic elastic properties. Al atom adsorption energies show significant orientation and surface termination dependence, with the strongest adsorption on (111)-N (∼7.87 eV) and the weakest on (100) (∼1.01 eV). Potential energy surface analysis and CI-NEB calculations revealed the following sequence of Al migration activation energies: TiN(111)-Ti (≈0.124 eV) < TiN(100) (≈0.498 eV) < TiN(110) (≈1.252 eV) < TiN(111)-N (≈1.462 eV). This confirms that strong adsorption is typically accompanied by high migration barriers, which microscopically suppresses uniform spreading while promoting localized adhesion. Substitutional doping studies on TiN(100) demonstrated that transition metal elements differentially modulate Al migration barriers: V doping significantly reduces the barrier to ≈0.211 eV, enhancing surface diffusion; Nb has minimal effect; whereas Hf, Zr, Sc, and Y generally increase barriers (to ≈0.782, 0.836, 0.903, and 1.173 eV, respectively). This effect is attributed to dopant-induced local lattice distortion and altered electronic state distribution, reshaping the potential energy landscape and diffusion pathways. Conclusively, interfacial wettability depends on balancing adsorption strength and surface diffusion capability. Moderate adsorption enhances interfacial bonding strength, while maintaining a low migration barrier is essential to promote uniform spreading of the metal layer. Selecting appropriate doping elements effectively achieves this balance.
{"title":"First-principles study on the effect of ceramic doping on the adsorption and migration behavior of Al atoms on TiN surfaces","authors":"Yuanjin Qian , Shiyang Sun , Duoduo Huang , Hengbing Chen","doi":"10.1016/j.susc.2025.122915","DOIUrl":"10.1016/j.susc.2025.122915","url":null,"abstract":"<div><div>This study aims to elucidate the regulation mechanism of elemental doping on the adsorption and migration behavior of Al atoms on TiN surfaces, providing a theoretical basis for optimizing the wettability and bonding properties at metal-ceramic interfaces. Density functional theory (DFT) based first-principles calculations were employed to systematically investigate the electronic structure and mechanical properties of bulk TiN, alongside the adsorption configurations and migration behavior of Al atoms on typical low-index TiN surfaces ((100), (110), (111)<sub>-N</sub>, (111)<sub>-Ti</sub>). The regulatory effects of dopants on migration barriers were also evaluated. Results indicate that bulk TiN exhibits metal-covalent hybrid bonding and anisotropic elastic properties. Al atom adsorption energies show significant orientation and surface termination dependence, with the strongest adsorption on (111)<sub>-N</sub> (∼7.87 eV) and the weakest on (100) (∼1.01 eV). Potential energy surface analysis and CI-NEB calculations revealed the following sequence of Al migration activation energies: TiN(111)<sub>-Ti</sub> (≈0.124 eV) < TiN(100) (≈0.498 eV) < TiN(110) (≈1.252 eV) < TiN(111)<sub>-N</sub> (≈1.462 eV). This confirms that strong adsorption is typically accompanied by high migration barriers, which microscopically suppresses uniform spreading while promoting localized adhesion. Substitutional doping studies on TiN(100) demonstrated that transition metal elements differentially modulate Al migration barriers: V doping significantly reduces the barrier to ≈0.211 eV, enhancing surface diffusion; Nb has minimal effect; whereas Hf, Zr, Sc, and Y generally increase barriers (to ≈0.782, 0.836, 0.903, and 1.173 eV, respectively). This effect is attributed to dopant-induced local lattice distortion and altered electronic state distribution, reshaping the potential energy landscape and diffusion pathways. Conclusively, interfacial wettability depends on balancing adsorption strength and surface diffusion capability. Moderate adsorption enhances interfacial bonding strength, while maintaining a low migration barrier is essential to promote uniform spreading of the metal layer. Selecting appropriate doping elements effectively achieves this balance.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122915"},"PeriodicalIF":1.8,"publicationDate":"2025-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145840086","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}
Pub Date : 2025-12-17DOI: 10.1016/j.susc.2025.122914
Aqeel Mohsin Ali , Ahmed Majeed Jaseem , Wisam Abdulhassan Radhi
Density functional theory (DFT) was utilized to investigate the potential interactions between B3C2N3 graphene-like nanosheets and three lung cancer biomarkers present in exhaled breath stage. This study focuses on sensing capability of three lung cancer biomarkers of volatile organic compounds (VOCs), namely, 2-propenal (C3H4O), acetone (C3H6O), and isoprene (C5H8). The selective capability of B3C2N3 monolayer as an effective surface towards these biomarkers is demonstrated. The B3C2N3 monolayer was theoretically confirmed to offer some sensing merits such as favorable adsorption energy, optical absorption, enhancing electrical conductivity, and preferable recovery time when conducted to the target VOCs biomarkers. To identify the adsorption mechanism between the target VOCs and the B3C2N3 surface, charge transfer distribution was evaluated using Mulliken population analysis. The monolayer surface exhibited electronic and φ-type sensor characteristics in the detection process of all studied biomarkers. To identify the dynamic and thermal stability of the constructed systems: 2-propenal/B3C2N3, acetone/B3C2N3, and isoprene/B3C2N3, molecular dynamics (MD) was performed after 5000 steps for 1 fs at ambient temperature. The results revealed that the B3C2N3 monolayer surface may serve as a promising sensor for the earliest stage diagnosis of lung cancer depended on biomarkers detection of exhaled breath patients.
{"title":"DFT insights into B3C2N3 nanosheets: A promising biosensor for the earliest stage detection of exhaled breath biomarkers in lung cancer","authors":"Aqeel Mohsin Ali , Ahmed Majeed Jaseem , Wisam Abdulhassan Radhi","doi":"10.1016/j.susc.2025.122914","DOIUrl":"10.1016/j.susc.2025.122914","url":null,"abstract":"<div><div>Density functional theory (DFT) was utilized to investigate the potential interactions between B<sub>3</sub>C<sub>2</sub>N<sub>3</sub> graphene-like nanosheets and three lung cancer biomarkers present in exhaled breath stage. This study focuses on sensing capability of three lung cancer biomarkers of volatile organic compounds (VOCs), namely, 2-propenal (C<sub>3</sub>H<sub>4</sub>O), acetone (C<sub>3</sub>H<sub>6</sub>O), and isoprene (C<sub>5</sub>H<sub>8</sub>). The selective capability of B<sub>3</sub>C<sub>2</sub>N<sub>3</sub> monolayer as an effective surface towards these biomarkers is demonstrated. The B<sub>3</sub>C<sub>2</sub>N<sub>3</sub> monolayer was theoretically confirmed to offer some sensing merits such as favorable adsorption energy, optical absorption, enhancing electrical conductivity, and preferable recovery time when conducted to the target VOCs biomarkers. To identify the adsorption mechanism between the target VOCs and the B<sub>3</sub>C<sub>2</sub>N<sub>3</sub> surface, charge transfer distribution was evaluated using Mulliken population analysis. The monolayer surface exhibited electronic and <em>φ</em>-type sensor characteristics in the detection process of all studied biomarkers. To identify the dynamic and thermal stability of the constructed systems: 2-propenal/B<sub>3</sub>C<sub>2</sub>N<sub>3</sub>, acetone/B<sub>3</sub>C<sub>2</sub>N<sub>3</sub>, and isoprene/B<sub>3</sub>C<sub>2</sub>N<sub>3</sub>, molecular dynamics (MD) was performed after 5000 steps for 1 fs at ambient temperature. The results revealed that the B<sub>3</sub>C<sub>2</sub>N<sub>3</sub> monolayer surface may serve as a promising sensor for the earliest stage diagnosis of lung cancer depended on biomarkers detection of exhaled breath patients.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122914"},"PeriodicalIF":1.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790359","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}
Pub Date : 2025-12-16DOI: 10.1016/j.susc.2025.122913
Shiji Zhu , Xiaojun Xin , Gang Chen , Pucha Song , Shulong Li , Hengtao Li , Chunsheng Guo , Yong Zhao
The development of high-performance anode materials is a pivotal challenge for advancing lithium-ion battery technology. Two-dimensional boron-carbon monolayers have emerged as promising candidates due to their tunable electronic properties and structural robustness. This study proposes a B₄C₁₂ monolayer as a potential high-capacity anode through systematic density functional theory calculations. Our first-principles results indicate that the B₄C₁₂ monolayer exhibits spontaneous lithium adsorption with favorable binding energy, ensuring structural integrity during lithiation. Notably, the theoretical specific capacity is several times higher than that of traditional graphite anodes. However, this considerable advantage remains theoretical, and its practical realization is contingent upon addressing critical challenges, such as the material's synthesis feasibility and long-term cycling stability under realistic battery operating conditions. Furthermore, the lithiated framework demonstrates minimal volume expansion, high mechanical stiffness, and considerable thermal stability, which are essential for safe operation. These theoretical insights suggest that the B₄C₁₂ monolayer, though not yet experimentally synthesized, represents a conceptually valuable model for guiding the development of next-generation anode materials.
{"title":"A two-dimensional non-metallic anode material for lithium-ion batteries with superior capacity and stability","authors":"Shiji Zhu , Xiaojun Xin , Gang Chen , Pucha Song , Shulong Li , Hengtao Li , Chunsheng Guo , Yong Zhao","doi":"10.1016/j.susc.2025.122913","DOIUrl":"10.1016/j.susc.2025.122913","url":null,"abstract":"<div><div>The development of high-performance anode materials is a pivotal challenge for advancing lithium-ion battery technology. Two-dimensional boron-carbon monolayers have emerged as promising candidates due to their tunable electronic properties and structural robustness. This study proposes a B₄C₁₂ monolayer as a potential high-capacity anode through systematic density functional theory calculations. Our first-principles results indicate that the B₄C₁₂ monolayer exhibits spontaneous lithium adsorption with favorable binding energy, ensuring structural integrity during lithiation. Notably, the theoretical specific capacity is several times higher than that of traditional graphite anodes. However, this considerable advantage remains theoretical, and its practical realization is contingent upon addressing critical challenges, such as the material's synthesis feasibility and long-term cycling stability under realistic battery operating conditions. Furthermore, the lithiated framework demonstrates minimal volume expansion, high mechanical stiffness, and considerable thermal stability, which are essential for safe operation. These theoretical insights suggest that the B₄C₁₂ monolayer, though not yet experimentally synthesized, represents a conceptually valuable model for guiding the development of next-generation anode materials.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122913"},"PeriodicalIF":1.8,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790358","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}
Pub Date : 2025-12-12DOI: 10.1016/j.susc.2025.122912
M. Hajjami , I. Chabri , A. Oubelkacem , Y. Benhouria , I. Essaoudi , A. Ainane
This study delves into the electronic, optical, and thermoelectric properties of Sr2XMoO6 (X = Fe, Cr) double perovskites, employing density functional theory (DFT) within the Quantum Espresso framework. In contrast to most previous works, which primarily focus on the cubic or tetragonal phases, this research explores the comparatively underexplored orthorhombic phase. The semi-metallic nature of these materials, driven by the metallic spin-down channel linked to Mo-d states, underscores their intriguing electronic structure. Optical analysis reveals static dielectric constants of 5.72 for Sr2FeMoO6 and 6.12 for Sr2CrMoO6, reflecting strong light-matter interactions. Notably, Sr2FeMoO6 exhibits a prominent absorption peak at 1.81 eV, which shifts to 2.32 eV upon Cr substitution, highlighting the materials’ tunable optical properties and their potential in advanced optoelectronic applications. On the thermoelectric front, both materials exhibit a declining figure of merit (ZT) with increasing temperature, yet Sr2FeMoO6 achieves a peak ZT of approximately 1.002 at 200 K, marking it as a promising candidate for low-temperature thermoelectric applications. By offering a comprehensive examination of these properties in a realistic low-symmetry phase, this study provides new insights into the multifunctional potential of orthorhombic Sr2XMoO6 compounds.
{"title":"Multifaceted exploration of Sr2XMoO6 (X=Fe, Cr) double perovskites: Electronic, optical, and thermoelectric insights","authors":"M. Hajjami , I. Chabri , A. Oubelkacem , Y. Benhouria , I. Essaoudi , A. Ainane","doi":"10.1016/j.susc.2025.122912","DOIUrl":"10.1016/j.susc.2025.122912","url":null,"abstract":"<div><div>This study delves into the electronic, optical, and thermoelectric properties of Sr<sub>2</sub>XMoO<sub>6</sub> (X = Fe, Cr) double perovskites, employing density functional theory (DFT) within the Quantum Espresso framework. In contrast to most previous works, which primarily focus on the cubic or tetragonal phases, this research explores the comparatively underexplored orthorhombic phase. The semi-metallic nature of these materials, driven by the metallic spin-down channel linked to Mo-d states, underscores their intriguing electronic structure. Optical analysis reveals static dielectric constants of 5.72 for Sr<sub>2</sub>FeMoO<sub>6</sub> and 6.12 for Sr<sub>2</sub>CrMoO<sub>6</sub>, reflecting strong light-matter interactions. Notably, Sr<sub>2</sub>FeMoO<sub>6</sub> exhibits a prominent absorption peak at 1.81 eV, which shifts to 2.32 eV upon Cr substitution, highlighting the materials’ tunable optical properties and their potential in advanced optoelectronic applications. On the thermoelectric front, both materials exhibit a declining figure of merit (Z<sub>T</sub>) with increasing temperature, yet Sr<sub>2</sub>FeMoO<sub>6</sub> achieves a peak Z<sub>T</sub> of approximately 1.002 at 200 K, marking it as a promising candidate for low-temperature thermoelectric applications. By offering a comprehensive examination of these properties in a realistic low-symmetry phase, this study provides new insights into the multifunctional potential of orthorhombic Sr<sub>2</sub>XMoO<sub>6</sub> compounds.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122912"},"PeriodicalIF":1.8,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790372","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}
Corrosion, the progressive breakdown of materials through chemical interactions with their surroundings, threatens industrial safety, finances, and the environment. Pyrazole-based compounds, owing to their distinctive chemical reactivity and potential biodegradability, have recently attracted attention as eco-friendly corrosion inhibitors. In this study, five novel pyrazole derivatives—(E)-6-benzylidene-2,3-diphenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (B1), (E)-6-(4-methylbenzylidene)-2-phenyl-3-(p-tolyl)-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (B2), (E)-6-(4-bromobenzylidene)-3-(4-bromophenyl)-2-phenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (B3), (E)-6-(4-methoxybenzylidene)-3-(4-methoxyphenyl)-2-phenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (B4), and (E)-4-(6-(4-(dimethylamino)benzylidene)-2-phenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazol-3-yl)-N,N dimethylaniline (B5) were investigated for their potential to inhibit corrosion on Fe(110) surfaces in the gas phase. The DFT method at the B3LYP/6–311++G(d,p) level was employed to analyze molecular reactivity, Corrosion inhibition, and electronic properties, while Monte Carlo (MC) simulations were used to investigate the adsorption behavior of the compounds on the Fe (110) surface in a variety of medium dry environments, and an Acidic environment (150 H2O). Comprehensive evaluation of the B1–B5 inhibitors, based on MC adsorption energy, and DFT method, like dipole moment, and energy gap, highlights notable trends in anticorrosive performance. B5 stands out with the strongest adsorption energy (−225.765 kcal/mol) in a dry environment, (-3360.46 kcal/mol) in an acidic environment, the largest dipole moment ∼5.00 Debye, and the narrowest energy gap 3.154 eV, affirming its superior inhibition efficiency. In contrast, B3 is the least effective due to weak adsorption and unfavorable electronic parameters, while B4 and B2 present intermediate but meaningful inhibitory properties. According to these results, B5 is the most reactive molecule and the most promising option for sophisticated corrosion inhibition applications.
{"title":"Computational insights into the corrosion inhibition mechanisms of pyrazole derivatives on Fe(110) surfaces: A DFT and monte carlo approach","authors":"Kosrat Nazad Kaka , Rebaz Obaid Kareem , Abdalla Ali Amin , Rebaz Anwar Omer , Yousif Hussein Azeez , Aras Abdalrahman Hamad","doi":"10.1016/j.susc.2025.122911","DOIUrl":"10.1016/j.susc.2025.122911","url":null,"abstract":"<div><div>Corrosion, the progressive breakdown of materials through chemical interactions with their surroundings, threatens industrial safety, finances, and the environment. Pyrazole-based compounds, owing to their distinctive chemical reactivity and potential biodegradability, have recently attracted attention as eco-friendly corrosion inhibitors. In this study, five novel pyrazole derivatives—(E)-6-benzylidene-2,3-diphenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (<strong>B1</strong>), (E)-6-(4-methylbenzylidene)-2-phenyl-3-(p-tolyl)-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (<strong>B2</strong>), (E)-6-(4-bromobenzylidene)-3-(4-bromophenyl)-2-phenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (<strong>B3</strong>), (E)-6-(4-methoxybenzylidene)-3-(4-methoxyphenyl)-2-phenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazole (<strong>B4</strong>), and (E)-4-(6-(4-(dimethylamino)benzylidene)-2-phenyl-2,3,3a,4,5,6-hexahydrocyclopenta[c]pyrazol-3-yl)-N,N dimethylaniline (<strong>B5</strong>) were investigated for their potential to inhibit corrosion on Fe(110) surfaces in the gas phase. The DFT method at the B3LYP/6–311++<em>G</em>(d,p) level was employed to analyze molecular reactivity, Corrosion inhibition, and electronic properties, while Monte Carlo (MC) simulations were used to investigate the adsorption behavior of the compounds on the Fe (110) surface in a variety of medium dry environments, and an Acidic environment (150 H2O). Comprehensive evaluation of the <strong>B1–B5</strong> inhibitors, based on MC adsorption energy, and DFT method, like dipole moment, and energy gap, highlights notable trends in anticorrosive performance. <strong>B5</strong> stands out with the strongest adsorption energy (−225.765 kcal/mol) in a dry environment<strong>, (</strong>-3360.46 kcal/mol) in <strong>an</strong> acidic environment, the largest dipole moment ∼5.00 Debye, and the narrowest energy gap 3.154 eV, affirming its superior inhibition efficiency. In contrast, <strong>B3</strong> is the least effective due to weak adsorption and unfavorable electronic parameters, while <strong>B4</strong> and <strong>B2</strong> present intermediate but meaningful inhibitory properties. According to these results, B5 is the most reactive molecule and the most promising option for sophisticated corrosion inhibition applications.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"766 ","pages":"Article 122911"},"PeriodicalIF":1.8,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790371","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}
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