Pub Date : 2025-11-01Epub Date: 2025-06-27DOI: 10.1016/j.susc.2025.122806
Zhe Xing , Dmytro Orlov , Elsebeth Schröder
Magnesium (Mg) is an abundant metal which has been used in aviation, medicine, hydrogen energy storage, etc. However, Mg can be rather reactive, and therefore an improved understanding of corrosion and oxidation mechanisms can enhance the efficiency of these processes to control and widen applications. The study presented here investigates the mechanisms of oxidation from the initial to full monolayer stages, on two low-index Mg surfaces, Mg(0001) and Mg. By analysing the valence electron changes during the oxidation process, we reveal a connection between oxidation and electron properties, suggesting that oxygen (O) atoms preferentially adsorb in the regions of charge accumulation on the surfaces. After the adsorption of a first O atom, the charge distribution on the surface changes, and following O atoms are attracted to neighbouring charge-rich regions. In addition, the oxidized Mg-O units form geometric structures initially different from the rocksalt structure commonly reported for a fully oxidized surface. In Mg(0001), the Mg-O unit structure transitions from a wurtzite type to hexagonal, while on Mg a more perfect Mg-O unit of wurtzite structure forms.
{"title":"Exploring the evolution of magnesium oxidation mechanisms by density functional theory","authors":"Zhe Xing , Dmytro Orlov , Elsebeth Schröder","doi":"10.1016/j.susc.2025.122806","DOIUrl":"10.1016/j.susc.2025.122806","url":null,"abstract":"<div><div>Magnesium (Mg) is an abundant metal which has been used in aviation, medicine, hydrogen energy storage, etc. However, Mg can be rather reactive, and therefore an improved understanding of corrosion and oxidation mechanisms can enhance the efficiency of these processes to control and widen applications. The study presented here investigates the mechanisms of oxidation from the initial to full monolayer stages, on two low-index Mg surfaces, Mg(0001) and Mg<span><math><mrow><mo>(</mo><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>0</mn><mo>)</mo></mrow></math></span>. By analysing the valence electron changes during the oxidation process, we reveal a connection between oxidation and electron properties, suggesting that oxygen (O) atoms preferentially adsorb in the regions of charge accumulation on the surfaces. After the adsorption of a first O atom, the charge distribution on the surface changes, and following O atoms are attracted to neighbouring charge-rich regions. In addition, the oxidized Mg-O units form geometric structures initially different from the rocksalt structure commonly reported for a fully oxidized surface. In Mg(0001), the Mg-O unit structure transitions from a wurtzite type to hexagonal, while on Mg<span><math><mrow><mo>(</mo><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>0</mn><mo>)</mo></mrow></math></span> a more perfect Mg-O unit of wurtzite structure forms.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122806"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144556825","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 : 2025-11-01Epub Date: 2025-06-24DOI: 10.1016/j.susc.2025.122805
Yu Yang , Wei Zuo , Mingzhang Lin
This study uses density functional theory (DFT) to investigate the adsorption of volatile polonium species (Po, Po2, PbPo, H2Po, and PoOH) on Pd, Pt, Au, and Cu (1 1 1) surfaces, critical for capturing radioactive polonium in lead-bismuth eutectic (LBE) nuclear coolants. Geometric optimizations and adsorption energy calculations show Pd and Pt (1 1 1) surfaces exhibit superior adsorption for most species: monatomic Po adsorbs strongest on Pd (−3.95 eV) via covalent/orbital hybridization; Po2 and PbPo form stable dissociative/cooperative bonds on Pd/Pt; H2Po shows weak physisorption on Au/Cu due to limited orbital overlap; PoOH favors Pt through hydrogen bonding and O-M interactions. Electron density changes (Δρ(r)) and partial density of states (PDOS) confirm strong chemisorption with electron accumulation and orbital hybridization, aligning with frontier orbital theory predictions. Adsorption trends follows the order of Pd/Pt > Cu > Au and the adsorption reactivity of Po species on the Pd(1 1 1) surfaces occur most spontaneously within LBE coolant operation temperature highlight Pd as promising for filter materials, providing a theoretical basis for mitigating polonium volatility in advanced nuclear systems.
{"title":"Analyzing the capture of volatile polonium-210 in lead-bismuth eutectic coolant environments on metallic Pb, Pt, Au, and Cu (1 1 1) adsorption surfaces based on density functional theory","authors":"Yu Yang , Wei Zuo , Mingzhang Lin","doi":"10.1016/j.susc.2025.122805","DOIUrl":"10.1016/j.susc.2025.122805","url":null,"abstract":"<div><div>This study uses density functional theory (DFT) to investigate the adsorption of volatile polonium species (Po, Po<sub>2</sub>, PbPo, H<sub>2</sub>Po, and PoOH) on Pd, Pt, Au, and Cu (1 1 1) surfaces, critical for capturing radioactive polonium in lead-bismuth eutectic (LBE) nuclear coolants. Geometric optimizations and adsorption energy calculations show Pd and Pt (1 1 1) surfaces exhibit superior adsorption for most species: monatomic Po adsorbs strongest on Pd (−3.95 eV) via covalent/orbital hybridization; Po<sub>2</sub> and PbPo form stable dissociative/cooperative bonds on Pd/Pt; H<sub>2</sub>Po shows weak physisorption on Au/Cu due to limited orbital overlap; PoOH favors Pt through hydrogen bonding and O-M interactions. Electron density changes (Δρ(r)) and partial density of states (PDOS) confirm strong chemisorption with electron accumulation and orbital hybridization, aligning with frontier orbital theory predictions. Adsorption trends follows the order of Pd/Pt > Cu > Au and the adsorption reactivity of Po species on the Pd(1 1 1) surfaces occur most spontaneously within LBE coolant operation temperature highlight Pd as promising for filter materials, providing a theoretical basis for mitigating polonium volatility in advanced nuclear systems.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122805"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144521544","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 : 2025-11-01Epub Date: 2025-07-16DOI: 10.1016/j.susc.2025.122812
Ali Raza Chachar , Basheer Ahmed Kalwar , Muhammad Rafique , Amir Mahmood Soomro , Zaheer Ahmed , Ahsanullah Memon
Partial discharges in SF6 circuit breakers decompose SF6 into low-fluorine gases, which react with trace moisture to form corrosive acids, degrading contacts and impairing arc quenching capacity, necessitating a 24/7 monitoring system for early detection and prevention. In this work, carbon boronitride (BC6N) monolayer is investigated for potential application of SF6 decomposed gases SO2, SO2F2, SOF2, H2S, and HF through DFT calculations. Adsorption performance through adsorption energy, charge density difference, density of states, while sensitivity through band structures, work function and transport transmission and recovery through recovery time calculations are evaluated. Results show that pristine BC6N is weakly absorbing the gas molecules, however, BC6N decorated with Fe and Co atoms chemisorbs the gas molecules with enhanced adsorption energy -1.01 to -1.61 eV and -0.95 to -1.58 eV respectively. Diffusion energy barrier calculation confirms that Fe and Co atoms don’t make clusters. Sensitivity of Fe/BC6N and Co/BC6N to gas molecules respectively follows: (67.5 % and 72.9 %) for SO2F2> (70.8 % and 65 %) for SOF2> (68.7 % and 62.5 %) for SO2> (64.5 % and 57.5 %) for H2S> (58.3 % and 50 %) for HF. Recovery time calculations results show that strongest adsorbed SO2F2 molecule takes 117.5 h to be desorbed at 498 K temperature, which is considerably shortened to 1.69 nanoseconds upon UV exposure. Our proposed substrates can actively adsorb, sense and instantaneously desorb the target gas molecules, proving that Fe/BC6N and Co/BC6N can potentially be highly sensitive and reusable gas sensors.
{"title":"Adsorption and sensing SF6 decomposed gases; SO2, SO2F2, SOF2, H2S, and HF on Fe and Co decorated monolayer BC6N. First-principles study","authors":"Ali Raza Chachar , Basheer Ahmed Kalwar , Muhammad Rafique , Amir Mahmood Soomro , Zaheer Ahmed , Ahsanullah Memon","doi":"10.1016/j.susc.2025.122812","DOIUrl":"10.1016/j.susc.2025.122812","url":null,"abstract":"<div><div>Partial discharges in SF<sub>6</sub> circuit breakers decompose SF<sub>6</sub> into low-fluorine gases, which react with trace moisture to form corrosive acids, degrading contacts and impairing arc quenching capacity, necessitating a 24/7 monitoring system for early detection and prevention. In this work, carbon boronitride (BC<sub>6</sub>N) monolayer is investigated for potential application of SF<sub>6</sub> decomposed gases SO<sub>2</sub>, SO<sub>2</sub>F<sub>2</sub>, SOF<sub>2</sub>, H<sub>2</sub>S, and HF through DFT calculations. Adsorption performance through adsorption energy, charge density difference, density of states, while sensitivity through band structures, work function and transport transmission and recovery through recovery time calculations are evaluated. Results show that pristine BC<sub>6</sub>N is weakly absorbing the gas molecules, however, BC<sub>6</sub>N decorated with Fe and Co atoms chemisorbs the gas molecules with enhanced adsorption energy -1.01 to -1.61 eV and -0.95 to -1.58 eV respectively. Diffusion energy barrier calculation confirms that Fe and Co atoms don’t make clusters. Sensitivity of Fe/BC<sub>6</sub>N and Co/BC<sub>6</sub>N to gas molecules respectively follows: (67.5 % and 72.9 %) for SO<sub>2</sub>F<sub>2</sub>> (70.8 % and 65 %) for SOF<sub>2</sub>> (68.7 % and 62.5 %) for SO<sub>2</sub>> (64.5 % and 57.5 %) for H<sub>2</sub>S> (58.3 % and 50 %) for HF. Recovery time calculations results show that strongest adsorbed SO<sub>2</sub>F<sub>2</sub> molecule takes 117.5 h to be desorbed at 498 K temperature, which is considerably shortened to 1.69 nanoseconds upon UV exposure. Our proposed substrates can actively adsorb, sense and instantaneously desorb the target gas molecules, proving that Fe/BC<sub>6</sub>N and Co/BC<sub>6</sub>N can potentially be highly sensitive and reusable gas sensors.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122812"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144758150","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 : 2025-11-01Epub Date: 2025-06-13DOI: 10.1016/j.susc.2025.122788
Jolanta Maksymiuk , Izabela A. Wrona , Radoslaw Szczesniak , Artur P. Durajski
We present a comprehensive first-principles investigation of the electronic and optical properties of monolayer MoS doped with p-block elements (B, C, N, O, Al, Si, P, Ga, Ge, As, and Se) at the sulfur site. Our calculations demonstrate that substitutional doping profoundly alters the band structure, introducing localized or hybridized impurity states that can reduce, close, or maintain the band gap, depending on the dopant. Notably, B, N, Al, and Ga induce metallic-like behavior, whereas O, C, Se, and Si preserve semiconducting characteristics. Partial density of states analysis reveals that states near the Fermi level are dominated by Mo and S orbitals, with dopants playing a critical secondary role in modulating the host electronic structure. Optical property calculations show dopant-dependent tunability of absorption and transparency across UV, visible, and infrared regions. For example, Al doping enhances UV absorption, while P doping modifies the infrared response. Remarkably, all doped systems retain high visible transparency (75%) despite structural and electronic perturbations, underscoring their potential for optoelectronic and transparent electronics applications. This work establishes substitutional doping as a powerful strategy for tailoring the electronic and optical properties of monolayer MoS for next-generation device engineering.
我们提出了一个全面的第一性原理研究在硫位点掺杂P块元素（B， C， N， O, Al, Si， P, Ga, Ge， As和Se）的单层MoS2的电子和光学性质。我们的计算表明，取代掺杂深刻地改变了能带结构，引入了局部或杂化的杂质态，这些杂质态可以减少、关闭或保持带隙，具体取决于掺杂物。值得注意的是，B、N、Al和Ga诱导了类似金属的行为，而O、C、Se和Si保持了半导体特性。态的部分密度分析表明，费米能级附近的态主要由Mo和S轨道控制，掺杂剂在调节主电子结构中起着关键的次要作用。光学性质计算表明，吸收和透明度在紫外光，可见光和红外区域依赖于掺杂剂的可调性。例如，Al掺杂增强了紫外吸收，而P掺杂改变了红外响应。值得注意的是，尽管结构和电子扰动，所有掺杂系统仍保持高可见透明度（>75%），强调了它们在光电和透明电子应用方面的潜力。这项工作建立了替代掺杂作为一种强大的策略，为下一代器件工程定制单层MoS2的电子和光学特性。
{"title":"Tunable optical and electronic properties of monolayer MoS2 via substitutional doping","authors":"Jolanta Maksymiuk , Izabela A. Wrona , Radoslaw Szczesniak , Artur P. Durajski","doi":"10.1016/j.susc.2025.122788","DOIUrl":"10.1016/j.susc.2025.122788","url":null,"abstract":"<div><div>We present a comprehensive first-principles investigation of the electronic and optical properties of monolayer MoS<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> doped with p-block elements (B, C, N, O, Al, Si, P, Ga, Ge, As, and Se) at the sulfur site. Our calculations demonstrate that substitutional doping profoundly alters the band structure, introducing localized or hybridized impurity states that can reduce, close, or maintain the band gap, depending on the dopant. Notably, B, N, Al, and Ga induce metallic-like behavior, whereas O, C, Se, and Si preserve semiconducting characteristics. Partial density of states analysis reveals that states near the Fermi level are dominated by Mo and S orbitals, with dopants playing a critical secondary role in modulating the host electronic structure. Optical property calculations show dopant-dependent tunability of absorption and transparency across UV, visible, and infrared regions. For example, Al doping enhances UV absorption, while P doping modifies the infrared response. Remarkably, all doped systems retain high visible transparency (<span><math><mo>></mo></math></span>75%) despite structural and electronic perturbations, underscoring their potential for optoelectronic and transparent electronics applications. This work establishes substitutional doping as a powerful strategy for tailoring the electronic and optical properties of monolayer MoS<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> for next-generation device engineering.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122788"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144297301","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 : 2025-11-01Epub Date: 2025-06-03DOI: 10.1016/j.susc.2025.122791
Hans-Peter Steinrück (Editor-in-Chief)
{"title":"60 years of surface science: Achievements and perspectives","authors":"Hans-Peter Steinrück (Editor-in-Chief)","doi":"10.1016/j.susc.2025.122791","DOIUrl":"10.1016/j.susc.2025.122791","url":null,"abstract":"","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122791"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841960","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 : 2025-11-01Epub Date: 2025-06-24DOI: 10.1016/j.susc.2025.122802
Tong Yuan , Guili Liu , Guoying Zhang
The effect of atomic doping of noble metals (Ag, Au, Pt, Pd) with high activity and stability on the adsorption of CO gas molecules by monolayers of SnSe2 is investigated by using the first principles, which is used to effectively improve the sensitivity of monolayers of SnSe2 to harmful gases. The most stable adsorption configuration of CO on the surface of the structure was found to be adsorbed with C atoms close to the crystal surface, slightly tilted, and perpendicular to the top of the hexagonal vacancies. With the embedding of noble metal atoms, the adsorption height and adsorption energy of CO on the system's surface decreased, the binding of CO on the system's surface increased, and the adsorption performance of the SnSe2 system was improved. The phonon dispersion analysis shows that all systems can be formed stably. The introduction of Au and Ag atoms makes the whole adsorption system metallic. The d-orbital electrons of dopant atoms enhance hybridization between Sn-4p and Se-4s orbitals, strengthening electronic interactions. Mulliken populations analysis shows that the number of charges for CO molecules to undergo transfer increases when the surface of the doped system absorbs CO molecules, and the surface activity of the system is enhanced.
{"title":"Precious metal (Ag, Au, Pt, Pd) doped monolayer SnSe2 adsorption of gas molecules CO","authors":"Tong Yuan , Guili Liu , Guoying Zhang","doi":"10.1016/j.susc.2025.122802","DOIUrl":"10.1016/j.susc.2025.122802","url":null,"abstract":"<div><div>The effect of atomic doping of noble metals (Ag, Au, Pt, Pd) with high activity and stability on the adsorption of CO gas molecules by monolayers of SnSe<sub>2</sub> is investigated by using the first principles, which is used to effectively improve the sensitivity of monolayers of SnSe<sub>2</sub> to harmful gases. The most stable adsorption configuration of CO on the surface of the structure was found to be adsorbed with C atoms close to the crystal surface, slightly tilted, and perpendicular to the top of the hexagonal vacancies. With the embedding of noble metal atoms, the adsorption height and adsorption energy of CO on the system's surface decreased, the binding of CO on the system's surface increased, and the adsorption performance of the SnSe<sub>2</sub> system was improved. The phonon dispersion analysis shows that all systems can be formed stably. The introduction of Au and Ag atoms makes the whole adsorption system metallic. The d-orbital electrons of dopant atoms enhance hybridization between Sn-4p and Se-4s orbitals, strengthening electronic interactions. Mulliken populations analysis shows that the number of charges for CO molecules to undergo transfer increases when the surface of the doped system absorbs CO molecules, and the surface activity of the system is enhanced.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122802"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144521543","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 : 2025-11-01Epub Date: 2025-06-01DOI: 10.1016/j.susc.2025.122789
Jamelah S. Al-Otaibi , Y. Sheena Mary , Maria Cristina Gamberini
Using density functional theory, the adsorption properties of lamotrigine (6-(2,3-dichlorophenyl)1,2,4-triazine-3,5-diamine) (DTD) with CC, AlN and BN nanotubes are reported. Different configurations are selected for optimization. The study addresses the need for efficient drug carriers by evaluating nanotubes (CC, BN, AlN) for lamotrigine (DTD) delivery. Key findings include: PP2 (NH₂-end) has the highest adsorption energy (–190.78 kJ/mol for AlN); SERS effects confirm DTD-nanotube binding, and MD shows stability in water/methanol. In all cases, DTD at the end of the nanotubes give maximum adsorption energy. For all complexes, adsorption energy varies as AlN-DTDPP2 (-190.78) > BNPP2 (-185.09) > CCPP2 (-14.86). The increase in polarizability suggests SERS effect is formed due to adsorption of DTD with nanotubes and the vibrational modes which are absent in the DTD is present in the Raman spectra of complexes. For different attempt frequencies the recovery times are found and very low for all CC-DTD, AlN-DTDPP1 and BN-DTDPP3. For AlN/BN-DTDPP2, the recovery times are very high and the sensing effects are also presented. High docking scores indicate the drug carrier activity of nanotubes. MD simulations are carried out for the complexes giving higher adsorption energy in water and methanol.
{"title":"Unlocking the potential of Lamotrigine in nanotubes: DFT, MD simulations in different solvents, sensing properties and drug enhancer","authors":"Jamelah S. Al-Otaibi , Y. Sheena Mary , Maria Cristina Gamberini","doi":"10.1016/j.susc.2025.122789","DOIUrl":"10.1016/j.susc.2025.122789","url":null,"abstract":"<div><div>Using density functional theory, the adsorption properties of lamotrigine (6-(2,3-dichlorophenyl)1,2,4-triazine-3,5-diamine) (DTD) with CC, AlN and BN nanotubes are reported. Different configurations are selected for optimization. The study addresses the need for efficient drug carriers by evaluating nanotubes (CC, BN, AlN) for lamotrigine (DTD) delivery. Key findings include: PP2 (NH₂-end) has the highest adsorption energy (–190.78 kJ/mol for AlN); SERS effects confirm DTD-nanotube binding, and MD shows stability in water/methanol. In all cases, DTD at the end of the nanotubes give maximum adsorption energy. For all complexes, adsorption energy varies as AlN-DTDPP2 (-190.78) > BNPP2 (-185.09) > CCPP2 (-14.86). The increase in polarizability suggests SERS effect is formed due to adsorption of DTD with nanotubes and the vibrational modes which are absent in the DTD is present in the Raman spectra of complexes. For different attempt frequencies the recovery times are found and very low for all CC-DTD, AlN-DTDPP1 and BN-DTDPP3. For AlN/BN-DTDPP2, the recovery times are very high and the sensing effects are also presented. High docking scores indicate the drug carrier activity of nanotubes. MD simulations are carried out for the complexes giving higher adsorption energy in water and methanol.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122789"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144223647","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 : 2025-11-01Epub Date: 2025-08-05DOI: 10.1016/j.susc.2025.122816
Saeid Khesali Azadi , Matti Alatalo , Marko Huttula , Timo Fabritius , Samuli Urpelainen
The reactivity of Fe2O3 oxygen carriers (OCs) in the presence of alkali and alkaline earth metal substitutions was investigated using density functional theory (DFT) to enhance their reduction behavior. Our calculations reveal that these substitutions preferentially occupy surface sites on Fe2O3[001], rather than the bulk. Compared to alkaline earth metals, the surface oxygen vacancy formation energy (Evac), a measure of reducibility, is substantially lower near alkali substitutions, indicating more oxygen release. Additionally, we investigated H2 oxidation and adsorption on pure and Na-substituted Fe2O3[001] surfaces that have an oxygen vacancy. Adsorption energies demonstrate that H2 preferentially dissociates on O top and hollow sites rather than on Fe-related sites. The oxidation of H2 is both thermodynamically and kinetically more advantageous on O sites, resulting in the production of H2O via either direct adsorption or H atom migration pathways. Conversely, Fe sites demonstrate elevated steric hindrances and reduced reactivity. Finally, oxygen migration from the bulk to the surface was identified as a mechanism driven by high temperatures, which may influence oxygen availability during cycling. These findings offer essential understanding of the impact of substitutions on the redox behavior of Fe2O3 OCs, relevant to applications in chemical looping and sustainable hydrogen consumption.
{"title":"The influence of alkali and alkaline earth substitution on the reduction of Fe2O3[001] by H2 – a DFT study","authors":"Saeid Khesali Azadi , Matti Alatalo , Marko Huttula , Timo Fabritius , Samuli Urpelainen","doi":"10.1016/j.susc.2025.122816","DOIUrl":"10.1016/j.susc.2025.122816","url":null,"abstract":"<div><div>The reactivity of Fe<sub>2</sub>O<sub>3</sub> oxygen carriers (OCs) in the presence of alkali and alkaline earth metal substitutions was investigated using density functional theory (DFT) to enhance their reduction behavior. Our calculations reveal that these substitutions preferentially occupy surface sites on Fe<sub>2</sub>O<sub>3</sub>[001], rather than the bulk. Compared to alkaline earth metals, the surface oxygen vacancy formation energy (E<sub>vac</sub>), a measure of reducibility, is substantially lower near alkali substitutions, indicating more oxygen release. Additionally, we investigated H<sub>2</sub> oxidation and adsorption on pure and Na-substituted Fe<sub>2</sub>O<sub>3</sub>[001] surfaces that have an oxygen vacancy. Adsorption energies demonstrate that H<sub>2</sub> preferentially dissociates on O top and hollow sites rather than on Fe-related sites. The oxidation of H<sub>2</sub> is both thermodynamically and kinetically more advantageous on O sites, resulting in the production of H<sub>2</sub>O via either direct adsorption or H atom migration pathways. Conversely, Fe sites demonstrate elevated steric hindrances and reduced reactivity. Finally, oxygen migration from the bulk to the surface was identified as a mechanism driven by high temperatures, which may influence oxygen availability during cycling. These findings offer essential understanding of the impact of substitutions on the redox behavior of Fe<sub>2</sub>O<sub>3</sub> OCs, relevant to applications in chemical looping and sustainable hydrogen consumption.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122816"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144781477","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 : 2025-11-01Epub Date: 2025-08-04DOI: 10.1016/j.susc.2025.122815
Lin Lin, Lingna Xu, Yingang Gui
<div><div>In the present investigation, the adsorption and gas-sensitive properties of industrial toxic gases (SO<sub>2</sub>, NO<sub>2</sub> and NH<sub>3</sub>) on transition metal (Rh, Pd, Pt) modified Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer was explored using density functional theory calculations. To gain insights into the change of adsorption and gas-sensitive properties of Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer modified with metal atoms, the structures of metal modification and gas adsorption on Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, charge transfer, adsorption energy, band structure, state density and molecular orbitals were analyzed. It is found that transition metal atoms' modification on the substrate improves the conductivity of Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer. Moreover, the optimal structures for the modification of Ti₃C₂F₂ with Rh, Pd and Pt have been identified, with the binding energies of -2.614 eV, -0.819 eV and -1.411 eV guaranteeing the stability of the three structures during the adsorption process. The adsorption capacity of the original Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> for SO<sub>2</sub>, NO<sub>2</sub> and NH<sub>3</sub> is weak physical adsorption with adsorption energies in the range of -0.2 eV to -0.4 eV. Compared with the original Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, the adsorption efficiency of Rh-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> and Pt-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> for SO<sub>2</sub>, NO<sub>2</sub> and NH<sub>3</sub> is significantly improved: the adsorption energies of Rh-Ti₃C₂F₂ for the three gases are -1.2 eV to -1.6 eV, Pd-Ti₃C₂F₂ are -1.6 eV to -1.8 eV, and Pt-Ti₃C₂F₂ are -1.1 eV to -2.2 eV, all reaching the level of chemical adsorption. In addition, the Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer exhibits high stability, and its structure remains unchanged after the adsorption of gases. Moreover, the analysis of the density of states indicates that Rh-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> exhibits the most pronounced interaction with NH<sub>3</sub> and the least significant interaction with NO<sub>2</sub>, whereas both Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> and Pt-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> display the greatest interaction with NO<sub>2</sub> and the weakest with NH<sub>3</sub>. Investigations into molecular orbitals suggest that Rh-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>'s electrical conductivity when exposed to gas molecules is as follows: NH<sub>3</sub> > SO<sub>2</sub> > NO<sub>2</sub>, and the <em>E</em><sub>g</sub>(variation) values of the three gases are 2.96 %, 2.70 % and 2.16 % respectively. For Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, the conductivity influenced by gases is NO<sub>2</sub> > NH<sub>3</sub> = SO<sub>2</sub> with the <em>E</em><sub>g</sub>(variation) values are 82.83 %, 1.26 % and 1.26 % respectively. Meanwhile, Pt-Ti<sub>
利用密度泛函理论计算，研究了过渡金属（Rh, Pd, Pt）修饰的Ti3C2F2单层对工业有毒气体（SO2， NO2和NH3）的吸附和气敏性能。为了深入了解金属原子修饰Ti3C2F2单层膜的吸附和气敏性能的变化，分析了Ti3C2F2表面金属修饰和气体吸附的结构、电荷转移、吸附能、能带结构、态密度和分子轨道。发现过渡金属原子在基体上的修饰提高了Ti3C2F2单层的导电性。此外，还确定了Rh、Pd和Pt改性Ti₃C₂F₂的最佳结构，其结合能分别为-2.614 eV、-0.819 eV和-1.411 eV，保证了三种结构在吸附过程中的稳定性。原始Ti3C2F2对SO2、NO2和NH3的吸附能力为弱物理吸附，吸附能在-0.2 ~ -0.4 eV之间。与原Ti3C2F2相比，Rh-Ti3C2F2、Pd-Ti3C2F2和Pt-Ti3C2F2对SO2、NO2和NH3的吸附效率显著提高：Rh-Ti₃C₂F₂对3种气体的吸附能为-1.2 eV ~ -1.6 eV， Pd-Ti₃C₂F₂为-1.6 eV ~ -1.8 eV， Pt-Ti₃C₂F₂为-1.1 eV ~ -2.2 eV，均达到化学吸附水平。此外，Pd-Ti3C2F2单层具有较高的稳定性，吸附气体后其结构保持不变。态密度分析表明，Rh-Ti3C2F2与NH3的相互作用最显著，与NO2的相互作用最不显著，而Pd-Ti3C2F2和Pt-Ti3C2F2与NO2的相互作用最大，与NH3的相互作用最弱。对分子轨道的研究表明，Rh-Ti3C2F2暴露于气体分子时的电导率如下：NH3 >；二氧化硫比;三种气体的NO2和Eg（变异）值分别为2.96%、2.70%和2.16%。对于Pd-Ti3C2F2，受气体影响的电导率为NO2 >；NH3 = SO2, Eg（变异）值分别为82.83%、1.26%和1.26%。同时，Pt-Ti3C2F2呈现出NO2 >顺序的电导率变化；二氧化硫比;当NH3暴露于气体分子时，Eg（变异）值分别为24.54%、16.71%和8.62%。这些研究结果为利用Rh-Ti3C2F2、Pd-Ti3C2F2和Pt-Ti3C2F2制作用于工业有害气体监测的气体传感器提供了理论基础。
{"title":"Adsorption and gas-sensitive properties of TM (Rh, Pd, Pt) modified Ti3C2F2 for SO2, NO2 and NH3 gas molecules: A DFT study","authors":"Lin Lin, Lingna Xu, Yingang Gui","doi":"10.1016/j.susc.2025.122815","DOIUrl":"10.1016/j.susc.2025.122815","url":null,"abstract":"<div><div>In the present investigation, the adsorption and gas-sensitive properties of industrial toxic gases (SO<sub>2</sub>, NO<sub>2</sub> and NH<sub>3</sub>) on transition metal (Rh, Pd, Pt) modified Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer was explored using density functional theory calculations. To gain insights into the change of adsorption and gas-sensitive properties of Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer modified with metal atoms, the structures of metal modification and gas adsorption on Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, charge transfer, adsorption energy, band structure, state density and molecular orbitals were analyzed. It is found that transition metal atoms' modification on the substrate improves the conductivity of Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer. Moreover, the optimal structures for the modification of Ti₃C₂F₂ with Rh, Pd and Pt have been identified, with the binding energies of -2.614 eV, -0.819 eV and -1.411 eV guaranteeing the stability of the three structures during the adsorption process. The adsorption capacity of the original Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> for SO<sub>2</sub>, NO<sub>2</sub> and NH<sub>3</sub> is weak physical adsorption with adsorption energies in the range of -0.2 eV to -0.4 eV. Compared with the original Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, the adsorption efficiency of Rh-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> and Pt-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> for SO<sub>2</sub>, NO<sub>2</sub> and NH<sub>3</sub> is significantly improved: the adsorption energies of Rh-Ti₃C₂F₂ for the three gases are -1.2 eV to -1.6 eV, Pd-Ti₃C₂F₂ are -1.6 eV to -1.8 eV, and Pt-Ti₃C₂F₂ are -1.1 eV to -2.2 eV, all reaching the level of chemical adsorption. In addition, the Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> monolayer exhibits high stability, and its structure remains unchanged after the adsorption of gases. Moreover, the analysis of the density of states indicates that Rh-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> exhibits the most pronounced interaction with NH<sub>3</sub> and the least significant interaction with NO<sub>2</sub>, whereas both Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> and Pt-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub> display the greatest interaction with NO<sub>2</sub> and the weakest with NH<sub>3</sub>. Investigations into molecular orbitals suggest that Rh-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>'s electrical conductivity when exposed to gas molecules is as follows: NH<sub>3</sub> > SO<sub>2</sub> > NO<sub>2</sub>, and the <em>E</em><sub>g</sub>(variation) values of the three gases are 2.96 %, 2.70 % and 2.16 % respectively. For Pd-Ti<sub>3</sub>C<sub>2</sub>F<sub>2</sub>, the conductivity influenced by gases is NO<sub>2</sub> > NH<sub>3</sub> = SO<sub>2</sub> with the <em>E</em><sub>g</sub>(variation) values are 82.83 %, 1.26 % and 1.26 % respectively. Meanwhile, Pt-Ti<sub>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122815"},"PeriodicalIF":1.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766970","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 : 2025-11-01Epub Date: 2025-06-17DOI: 10.1016/j.susc.2025.122804
Zicheng Jiang, Ting Zheng, Wenwen Zhang, Linqiang Tao
UHMWPE is a vital material used in artificial joint replacements because of its excellent mechanical properties and wear resistance. This study systematically investigated the development process and the evolution mechanism of plastic deformation of UHMWPE. The plastic deformation layer that protrudes at the edge of the groove grows gradually and stabilizes over time, while a higher rotation speed leads to a faster development of the protruded plastic layers. Raman spectroscopy results in the worn surface show increased crystallinity in the plastic deformation layers, especially at the groove edges, implying ordered distributions of microstructures. The scratch and indentation results indicate a densely packed but anisotropic distribution of microstructures in UHMWPE. Additionally, MD simulation results indicate that the frictional process creates ordered distributions of polyethylene chains, thereby enhancing the interaction strength between adjacent molecular chains. The compactly arranged polyethylene chains flow along the frictional direction as the Fe slab moves linearly, and show the potential to separate from the undeformed substrate in UHMWPE, forming the plastic deformation layer. More PE chains aligned parallel to friction at the initial stage could result in greater plastic deformations. These results offer new insights into the wear mechanisms of UHMWPE, showing that the wear of UHMWPE is closely linked to the development of the plastic deformation layer.
{"title":"Development process and evolution mechanism of microstructures of friction-induced plastic deformation layers on UHMWPE","authors":"Zicheng Jiang, Ting Zheng, Wenwen Zhang, Linqiang Tao","doi":"10.1016/j.susc.2025.122804","DOIUrl":"10.1016/j.susc.2025.122804","url":null,"abstract":"<div><div>UHMWPE is a vital material used in artificial joint replacements because of its excellent mechanical properties and wear resistance. This study systematically investigated the development process and the evolution mechanism of plastic deformation of UHMWPE. The plastic deformation layer that protrudes at the edge of the groove grows gradually and stabilizes over time, while a higher rotation speed leads to a faster development of the protruded plastic layers. Raman spectroscopy results in the worn surface show increased crystallinity in the plastic deformation layers, especially at the groove edges, implying ordered distributions of microstructures. The scratch and indentation results indicate a densely packed but anisotropic distribution of microstructures in UHMWPE. Additionally, MD simulation results indicate that the frictional process creates ordered distributions of polyethylene chains, thereby enhancing the interaction strength between adjacent molecular chains. The compactly arranged polyethylene chains flow along the frictional direction as the Fe slab moves linearly, and show the potential to separate from the undeformed substrate in UHMWPE, forming the plastic deformation layer. More PE chains aligned parallel to friction at the initial stage could result in greater plastic deformations. These results offer new insights into the wear mechanisms of UHMWPE, showing that the wear of UHMWPE is closely linked to the development of the plastic deformation layer.</div></div>","PeriodicalId":22100,"journal":{"name":"Surface Science","volume":"761 ","pages":"Article 122804"},"PeriodicalIF":2.1,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330575","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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