Xiufeng Gong, Jin Yao, Wanzhong Yin, Ningbo Song, Yulian Wang
This study investigated the relation between the solubility and floatability of the soluble mineral brucite, focusing on the concentration characteristics of dissolved Mg2+ in brucite under three dissolution methods and the surface characteristics after dissolution. Some common rules of brucite flotation in three anionic collectors were discovered. Results of a flotation test showed that for three anionic collector systems of sodium oleate, sodium dodecyl sulfonate, and oxidized paraffin soap, the flotation recovery rate of brucite increased with the time of dissolution and decreased with the removal of dissolved Mg2+, but the flotation recovery rate is lower than that of untreated brucite. Inductively coupled plasma spectroscopy indicated that the content of dissolved Mg2+ in brucite slurry increases with increasing brucite content or dissolution time. Zeta potential measurements showed that the ability of dissolved Mg2+ to increase the surface potential of brucite follows the order of H2SO4 action > HCl action > H2O action. Adsorption capacity measurements showed that the presence of dissolved Mg2+ after dissolution is not beneficial for the adsorption of the three collectors on the surface of brucite. The capacity of the adsorption collectors follows the order of brucite after H2O dissolution > brucite after HCl dissolution > brucite after H2SO4 dissolution. Scanning electron microscopy and X‐ray photoelectron spectroscopy analyses indicated that the surface dissolution promoted the dissolution of Mg2+ on brucite surface in the solution, reducing the number of Mg sites on brucite surface and deteriorating the collection effect of the collector.
{"title":"Effect of Surface Dissolution on the Floatability of Brucite in Three Anionic Collector Systems","authors":"Xiufeng Gong, Jin Yao, Wanzhong Yin, Ningbo Song, Yulian Wang","doi":"10.1002/sia.7355","DOIUrl":"https://doi.org/10.1002/sia.7355","url":null,"abstract":"This study investigated the relation between the solubility and floatability of the soluble mineral brucite, focusing on the concentration characteristics of dissolved Mg<jats:sup>2+</jats:sup> in brucite under three dissolution methods and the surface characteristics after dissolution. Some common rules of brucite flotation in three anionic collectors were discovered. Results of a flotation test showed that for three anionic collector systems of sodium oleate, sodium dodecyl sulfonate, and oxidized paraffin soap, the flotation recovery rate of brucite increased with the time of dissolution and decreased with the removal of dissolved Mg<jats:sup>2+</jats:sup>, but the flotation recovery rate is lower than that of untreated brucite. Inductively coupled plasma spectroscopy indicated that the content of dissolved Mg<jats:sup>2+</jats:sup> in brucite slurry increases with increasing brucite content or dissolution time. Zeta potential measurements showed that the ability of dissolved Mg<jats:sup>2+</jats:sup> to increase the surface potential of brucite follows the order of H<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> action > HCl action > H<jats:sub>2</jats:sub>O action. Adsorption capacity measurements showed that the presence of dissolved Mg<jats:sup>2+</jats:sup> after dissolution is not beneficial for the adsorption of the three collectors on the surface of brucite. The capacity of the adsorption collectors follows the order of brucite after H<jats:sub>2</jats:sub>O dissolution > brucite after HCl dissolution > brucite after H<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> dissolution. Scanning electron microscopy and X‐ray photoelectron spectroscopy analyses indicated that the surface dissolution promoted the dissolution of Mg<jats:sup>2+</jats:sup> on brucite surface in the solution, reducing the number of Mg sites on brucite surface and deteriorating the collection effect of the collector.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187368","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}
Conductivity chromium‐free conversion coatings on aluminum substrates were achieved by utilizing Na2SnO3 and Mo/Ti solutions. The composition and morphology of the coatings were characterized using XPS, SEM, EDS, AFM, and Raman spectroscopies. The corrosion behavior of the coatings in 3.5‐wt% NaCl solution was investigated through a dynamic potential polarization method and EIS analysis. Mott–Schottky and UV–Vis analyses were used to determine the semiconductor properties of the coatings, including carrier concentration and band gap. The results revealed that the main components of the coating were Al2O3, SnO2, MoO3, and MoO2 and the coating presented a double‐layer structure, including a transition layer close to the substrate and a compact layer on the surface. The coating also exhibited the properties of a p‐type semiconductor. The electrical contact resistance value of adding Na2SnO3 decreased from 0.4331 to 0.1343 Ω/in2 (in 200 psi), while the band gap decreased from 2.281 to 2.232 eV.
{"title":"Preparation and Properties of Mo/Ti/Sn Conductivity Conversion Coatings on 6063 Aluminum Alloy","authors":"Aihua Yi, Min Liu, Wenfang Li, Yuying Liu, Yeping Mo, Zhiquan Huang, Xiaolan Chen","doi":"10.1002/sia.7352","DOIUrl":"https://doi.org/10.1002/sia.7352","url":null,"abstract":"Conductivity chromium‐free conversion coatings on aluminum substrates were achieved by utilizing Na<jats:sub>2</jats:sub>SnO<jats:sub>3</jats:sub> and Mo/Ti solutions. The composition and morphology of the coatings were characterized using XPS, SEM, EDS, AFM, and Raman spectroscopies. The corrosion behavior of the coatings in 3.5‐wt% NaCl solution was investigated through a dynamic potential polarization method and EIS analysis. Mott–Schottky and UV–Vis analyses were used to determine the semiconductor properties of the coatings, including carrier concentration and band gap. The results revealed that the main components of the coating were Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, SnO<jats:sub>2</jats:sub>, MoO<jats:sub>3</jats:sub>, and MoO<jats:sub>2</jats:sub> and the coating presented a double‐layer structure, including a transition layer close to the substrate and a compact layer on the surface. The coating also exhibited the properties of a p‐type semiconductor. The electrical contact resistance value of adding Na<jats:sub>2</jats:sub>SnO<jats:sub>3</jats:sub> decreased from 0.4331 to 0.1343 Ω/in<jats:sup>2</jats:sup> (in 200 psi), while the band gap decreased from 2.281 to 2.232 eV.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187370","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}
Leonid A. Aslanov, Vladimir B. Zaitsev, Valery N. Zakharov, Igor K. Kudryavtsev, Vladimir M. Senyavin, Petr B. Lagov, Elena P. Romanteeva
Silicon nanopowders with nitrogen heterocyclic carbene (NHC) and butyl as stabilizing ligands were synthesized by bottom‐up chemical methods. Transmission electron microscopy (TEM) was used to obtain nanoparticle size distribution with 1.8–2.5‐nm average diameter. Optical characteristics (photoluminescence [PL] and infrared [IR] absorption spectra) of samples were investigated as fabricated and on different steps of irradiation by high‐energy 22.5‐MeV protons. The PL spectral changes are slightly different for two cases, but in general, we can see a decrease in luminescence amplitude with fluence growth up to 4·1014 cm−2, mainly for NHC‐stabilized nanosilicon. Main mechanisms of radiation‐induced changes in nanosilicon sample optical properties are discussed by the joint use of PL and IR spectra analysis.
{"title":"Nanosilicon Stabilized With Ligands: Effect of High‐Energy Proton Beam on Luminescent Properties","authors":"Leonid A. Aslanov, Vladimir B. Zaitsev, Valery N. Zakharov, Igor K. Kudryavtsev, Vladimir M. Senyavin, Petr B. Lagov, Elena P. Romanteeva","doi":"10.1002/sia.7354","DOIUrl":"https://doi.org/10.1002/sia.7354","url":null,"abstract":"Silicon nanopowders with nitrogen heterocyclic carbene (NHC) and butyl as stabilizing ligands were synthesized by bottom‐up chemical methods. Transmission electron microscopy (TEM) was used to obtain nanoparticle size distribution with 1.8–2.5‐nm average diameter. Optical characteristics (photoluminescence [PL] and infrared [IR] absorption spectra) of samples were investigated as fabricated and on different steps of irradiation by high‐energy 22.5‐MeV protons. The PL spectral changes are slightly different for two cases, but in general, we can see a decrease in luminescence amplitude with fluence growth up to 4·10<jats:sup>14</jats:sup> cm<jats:sup>−2</jats:sup>, mainly for NHC‐stabilized nanosilicon. Main mechanisms of radiation‐induced changes in nanosilicon sample optical properties are discussed by the joint use of PL and IR spectra analysis.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187369","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}
Jaekwang Lee, Hyunwoo Lim, Joo‐yeon Ha, Seungjae Lee, Heesoo Lee
The electrical properties of acid‐treated CNT were investigated in terms of functional group and microstructure. A mixture of HNO3 and H2SO4 was used to acid treatment of CNT, and acid‐treated CNTs were synthesized by the mixture for 0 to 5 h. In crystal structure analysis, as acid treatment time was increased, the intensity of graphite diffraction peak was decreased and shifted to lower angle. It indicates a decrease in the crystallinity of CNT surface and lattice contraction by loss of carbon atoms. The distribution of oxygen on CNT surface was observed by TEM analysis confirming that functional groups and structural defects were formed. ID/IG ratio and average distance between defects (LD) were calculated using Raman spectroscopy to analyze the structural characteristics of CNT, and the greatest decrease was identified from p‐CNT to 2h‐CNT, resulting in the formation of functional groups and the changes in structural defects on CNT surface by acid treatment in the initial stage. Bonding state on CNT surface was analyzed through XPS analysis, and functional groups such as CO and COH were confirmed in acid‐treated CNT. Sheet resistance was measured to analyze the electrical properties of CNT, and 3h‐CNT showed the lowest sheet resistance at 25.28 Ω.
{"title":"Structural Analysis and Electrical Property of Acid‐Treated MWCNT","authors":"Jaekwang Lee, Hyunwoo Lim, Joo‐yeon Ha, Seungjae Lee, Heesoo Lee","doi":"10.1002/sia.7353","DOIUrl":"https://doi.org/10.1002/sia.7353","url":null,"abstract":"The electrical properties of acid‐treated CNT were investigated in terms of functional group and microstructure. A mixture of HNO<jats:sub>3</jats:sub> and H<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> was used to acid treatment of CNT, and acid‐treated CNTs were synthesized by the mixture for 0 to 5 h. In crystal structure analysis, as acid treatment time was increased, the intensity of graphite diffraction peak was decreased and shifted to lower angle. It indicates a decrease in the crystallinity of CNT surface and lattice contraction by loss of carbon atoms. The distribution of oxygen on CNT surface was observed by TEM analysis confirming that functional groups and structural defects were formed. I<jats:sub>D</jats:sub>/I<jats:sub>G</jats:sub> ratio and average distance between defects (L<jats:sub>D</jats:sub>) were calculated using Raman spectroscopy to analyze the structural characteristics of CNT, and the greatest decrease was identified from p‐CNT to 2h‐CNT, resulting in the formation of functional groups and the changes in structural defects on CNT surface by acid treatment in the initial stage. Bonding state on CNT surface was analyzed through XPS analysis, and functional groups such as CO and COH were confirmed in acid‐treated CNT. Sheet resistance was measured to analyze the electrical properties of CNT, and 3h‐CNT showed the lowest sheet resistance at 25.28 Ω.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187371","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}
Tamerlan T. Magkoev, Yong Men, Reza Behjatmanesh‐Ardakani, Mohammadreza Elahifard, Vladimir T. Abaev, Petrakis Chalikidi, Taymuraz T. Magkoev, Oleg G. Ashkhotov
It is demonstrated by means of ultra high vacuum (UHV) surface‐sensitive techniques and periodic density functional theory (DFT) calculations that the electronic and NO− adsorption properties of nanosized Ni clusters deposited onto the α‐Al2O3 (0001) surface significantly depend upon the size of the cluster. The properties of the Ni cluster of the size of 2 nm and lower are predominantly determined by the formation of the Ni/Al2O3 interface bond notably polarized towards the oxide. As a result, the metal cluster acquires a net positive charge manifested by the bond strengthening of adsorbed NO compared to the bulk Ni substrate. With the increasing size of the cluster, the Ni/Al2O3 interfacial bond depolarizes due to the growing of lateral Ni–Ni interaction. With a mean coverage of Ni on the alumina surface exceeding 0.25 equivalent monolayers, their properties in terms of adsorption behavior of NO resemble those that are characteristic for the bulk Ni substrate. Such a size dependence offers an opportunity to tune the properties of metal clusters and the metal/oxide system as a whole, for example, to achieve the required electronic and adsorption‐reaction properties.
通过超高真空（UHV）表面敏感技术和周期性密度泛函理论（DFT）计算，证明了沉积在 αAl2O3 (0001) 表面的纳米级镍团簇的电子和氮氧化物吸附特性明显取决于团簇的尺寸。尺寸为 2 nm 及以下的镍簇的特性主要取决于镍/Al2O3 界面键的形成，该键明显向氧化物极化。因此，金属簇获得了净正电荷，表现为与块状镍基底相比，吸附 NO 的键增强。随着金属簇大小的增加，镍/Al2O3 界面键由于镍-镍横向相互作用的增加而去极化。由于氧化铝表面镍的平均覆盖率超过 0.25 个等效单层，它们在吸附 NO 方面的特性与块状镍基底的特性相似。这种尺寸依赖性为调整金属团簇和整个金属/氧化物系统的特性提供了机会，例如，实现所需的电子和吸附反应特性。
{"title":"Combined Experimental and Periodic DFT Study of the Size Dependence of Adsorption Properties of Oxide‐Supported Metal Nanoclusters: A Case of NO on Ni/Al2O3","authors":"Tamerlan T. Magkoev, Yong Men, Reza Behjatmanesh‐Ardakani, Mohammadreza Elahifard, Vladimir T. Abaev, Petrakis Chalikidi, Taymuraz T. Magkoev, Oleg G. Ashkhotov","doi":"10.1002/sia.7350","DOIUrl":"https://doi.org/10.1002/sia.7350","url":null,"abstract":"It is demonstrated by means of ultra high vacuum (UHV) surface‐sensitive techniques and periodic density functional theory (DFT) calculations that the electronic and NO− adsorption properties of nanosized Ni clusters deposited onto the α‐Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> (0001) surface significantly depend upon the size of the cluster. The properties of the Ni cluster of the size of 2 nm and lower are predominantly determined by the formation of the Ni/Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> interface bond notably polarized towards the oxide. As a result, the metal cluster acquires a net positive charge manifested by the bond strengthening of adsorbed NO compared to the bulk Ni substrate. With the increasing size of the cluster, the Ni/Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> interfacial bond depolarizes due to the growing of lateral Ni–Ni interaction. With a mean coverage of Ni on the alumina surface exceeding 0.25 equivalent monolayers, their properties in terms of adsorption behavior of NO resemble those that are characteristic for the bulk Ni substrate. Such a size dependence offers an opportunity to tune the properties of metal clusters and the metal/oxide system as a whole, for example, to achieve the required electronic and adsorption‐reaction properties.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187372","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}
Pratiksha Agnihotri, Aman Verma, Anjali Saini, Rashmi Rani, W. Maudez, E. Wagner, G. Benvenuti, Chandan Banerjee, Mrinal Dutta, Radheshyam Rai
The application of variable angle spectroscopic ellipsometry (VASE) to the characterization of thin films is very important because it facilitates the understanding of their physical and optical properties. To prepare a series of film samples consisting of TiO2:ZrO2 on a TiN/Si substrate, we employed the SYBILLA P200 equipment (manufactured by ABCD Technology) through the process of Chemical Beam Vapor Deposition (CBVD). TiO2:ZrO2 on TiN/Si thin films is a composite material that has gained significant attention in various technological applications, particularly in the field of thin film coatings on semiconductor substrates like TiN/Si. TiO2:ZrO2 thin films exhibit excellent dielectric properties and good thermal stability, making them suitable for various electronic and semiconductor applications. From FESEM and EDX analysis, it is found that with increase of Ti/Zr atomic ratio, grain size increases. Ellipsometric analysis reveals increase in film thickness and refractive index with increase in Ti/Zr atomic ratio. As the film continues to grow, changes in its microstructural phase led to a transition from a monolayer physical ellipsometry model to a bilayer physical model. This transition is due to the appearance of inhomogeneity in the TiO2:ZrO2 thin film. Dynamic fits obtained using a two‐layer physical model and a Cauchy–Lorentz optical model show three distinct phases in the film growth phase: a nucleation phase, a fusion phase, and a continuous layer phase. Although our proposed model shows satisfactory performance in most cases, the determination of the refractive index can be problematic for very thin thicknesses. The developed VASE modeling process should be able to generate TiO2:ZrO2characterization on TiN/Si substrate films using comparable physical and optical modeling considerations.
{"title":"A spectroscopic ellipsometry study of TiO2:ZrO2 on TiN/Si thin films prepared by Chemical Beam Vapor Deposition","authors":"Pratiksha Agnihotri, Aman Verma, Anjali Saini, Rashmi Rani, W. Maudez, E. Wagner, G. Benvenuti, Chandan Banerjee, Mrinal Dutta, Radheshyam Rai","doi":"10.1002/sia.7348","DOIUrl":"https://doi.org/10.1002/sia.7348","url":null,"abstract":"The application of variable angle spectroscopic ellipsometry (VASE) to the characterization of thin films is very important because it facilitates the understanding of their physical and optical properties. To prepare a series of film samples consisting of TiO2:ZrO2 on a TiN/Si substrate, we employed the SYBILLA P200 equipment (manufactured by ABCD Technology) through the process of Chemical Beam Vapor Deposition (CBVD). TiO2:ZrO2 on TiN/Si thin films is a composite material that has gained significant attention in various technological applications, particularly in the field of thin film coatings on semiconductor substrates like TiN/Si. TiO2:ZrO2 thin films exhibit excellent dielectric properties and good thermal stability, making them suitable for various electronic and semiconductor applications. From FESEM and EDX analysis, it is found that with increase of Ti/Zr atomic ratio, grain size increases. Ellipsometric analysis reveals increase in film thickness and refractive index with increase in Ti/Zr atomic ratio. As the film continues to grow, changes in its microstructural phase led to a transition from a monolayer physical ellipsometry model to a bilayer physical model. This transition is due to the appearance of inhomogeneity in the TiO2:ZrO2 thin film. Dynamic fits obtained using a two‐layer physical model and a Cauchy–Lorentz optical model show three distinct phases in the film growth phase: a nucleation phase, a fusion phase, and a continuous layer phase. Although our proposed model shows satisfactory performance in most cases, the determination of the refractive index can be problematic for very thin thicknesses. The developed VASE modeling process should be able to generate TiO2:ZrO2characterization on TiN/Si substrate films using comparable physical and optical modeling considerations.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141922840","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}
LiFe5O8 is regarded as a promising material, which is used as anode for lithium‐ion batteries on account of its lower cost and higher theoretical capacity. However, its practical applications are hindered by the low electron transfer rate, poor cycling performance, and huge magnification of lattice volume. In this work, a LiFe5O8/carbon nanotubes (CNTs) composite anode is designed to realize the ideal anode for low‐cost lithium‐ion batteries, showing broad commercial application prospects. It is found that the three‐dimensional conductive network of CNTs is used to accelerate electron transfer rate within the LiFe5O8 particles, thereby significantly reducing the reversible reaction barrier (Fe/Fe3O4). In addition, it can also alleviate the volume change of electrode, which maintains a stable Li+ insertion/extraction behavior during long‐term cycles. As a consequence, there is still a high capacity (427.3 mAh g−1) of the LiFe5O8/CNTs 3% anode reserved after 50 cycles at 0.5 C whereas the bare LiFe5O8 anode only delivers a low capacity of 220.6 mAh g−1 along with a poor cycling stability. This work highlights the outstanding contribution of electronic conductivity toward the electrochemical performance of LiFe5O8 anode and provides a low‐cost and commercially applicable composite anode for developing lower cost lithium‐ion batteries.
LiFe5O8 是一种前景广阔的材料，因其成本低、理论容量高而被用作锂离子电池的负极。然而，电子转移率低、循环性能差以及晶格体积的巨大放大阻碍了它的实际应用。本研究设计了一种 LiFe5O8/碳纳米管（CNTs）复合负极，实现了低成本锂离子电池的理想负极，具有广阔的商业应用前景。研究发现，碳纳米管的三维导电网络可用于加快 LiFe5O8 颗粒内的电子转移率，从而显著降低可逆反应势垒（Fe/Fe3O4）。此外，它还能缓解电极的体积变化，从而在长期循环过程中保持稳定的 Li+ 插入/抽取行为。因此，LiFe5O8/CNTs 3% 阳极在 0.5 C 条件下循环 50 次后仍能保持较高的容量（427.3 mAh g-1），而裸 LiFe5O8 阳极仅能提供 220.6 mAh g-1 的低容量，且循环稳定性较差。这项研究强调了电子导电性对 LiFe5O8 负极电化学性能的突出贡献，并为开发低成本锂离子电池提供了一种低成本、商业化的复合负极。
{"title":"Three‐dimensional carbon nanotube framework enables low‐cost LiFe5O8 anode material for high‐performance lithium‐ion batteries","authors":"Lei Li, Jinsheng Huo, Qiwen Ran, Xingquan Liu","doi":"10.1002/sia.7347","DOIUrl":"https://doi.org/10.1002/sia.7347","url":null,"abstract":"LiFe<jats:sub>5</jats:sub>O<jats:sub>8</jats:sub> is regarded as a promising material, which is used as anode for lithium‐ion batteries on account of its lower cost and higher theoretical capacity. However, its practical applications are hindered by the low electron transfer rate, poor cycling performance, and huge magnification of lattice volume. In this work, a LiFe<jats:sub>5</jats:sub>O<jats:sub>8</jats:sub>/carbon nanotubes (CNTs) composite anode is designed to realize the ideal anode for low‐cost lithium‐ion batteries, showing broad commercial application prospects. It is found that the three‐dimensional conductive network of CNTs is used to accelerate electron transfer rate within the LiFe<jats:sub>5</jats:sub>O<jats:sub>8</jats:sub> particles, thereby significantly reducing the reversible reaction barrier (Fe/Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub>). In addition, it can also alleviate the volume change of electrode, which maintains a stable Li<jats:sup>+</jats:sup> insertion/extraction behavior during long‐term cycles. As a consequence, there is still a high capacity (427.3 mAh g<jats:sup>−1</jats:sup>) of the LiFe<jats:sub>5</jats:sub>O<jats:sub>8</jats:sub>/CNTs 3% anode reserved after 50 cycles at 0.5 C whereas the bare LiFe<jats:sub>5</jats:sub>O<jats:sub>8</jats:sub> anode only delivers a low capacity of 220.6 mAh g<jats:sup>−1</jats:sup> along with a poor cycling stability. This work highlights the outstanding contribution of electronic conductivity toward the electrochemical performance of LiFe<jats:sub>5</jats:sub>O<jats:sub>8</jats:sub> anode and provides a low‐cost and commercially applicable composite anode for developing lower cost lithium‐ion batteries.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945020","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}
Ali Reza Sarikhani, Mohammad Reza Salehi, Seyedeh Leila Mortazavifar, Mojtaba Shahraki, Ebrahim Abiri
In this paper, a perfect absorber (PA) based on tungsten is proposed to include hexagonal‐shaped metasurface absorbers with varying hole sizes ranging from quadrangular to circular, allowing them to cover a wide wavelength spectrum. The study investigates the effects of various parameters, including the number of sides of the inner hole, on the absorber's performance and identifies the most suitable absorber by introducing an equivalent circuit. The outcomes of full‐wave numerical simulations primarily based on the finite element method (FEM) highly correspond to the final results of the circuit model. Additionally, the circuit model significantly reduces computation time and requires less storage compared with full‐wave simulations. The results show that the hexagonal‐square metasurface absorber achieves exceptional absorption rates, with an average of 99.9% in the 431 to 532 nm wavelength range and over 90% in the 300 to 915 nm range. The hexagonal‐hexagonal metasurface absorber also exhibits high absorption rates, with an average of over 99% in the 431 to 518 nm and 700 to 780 nm ranges, and over 90% in the 300 to 940 nm range. The absorption performance of the proposed hexagonal‐circle metasurface absorber is also remarkable, with an absorption value of over 99% in the 670 to 771 nm range and above 90% in the 365 to 991 nm range. These models can be utilized to design and simulate other subwavelength absorbers in a broad frequency range, including terahertz and visible light, making them suitable for various applications.
{"title":"Design and optimization of hexagonal tungsten ring metasurface perfect absorbers with circuit model","authors":"Ali Reza Sarikhani, Mohammad Reza Salehi, Seyedeh Leila Mortazavifar, Mojtaba Shahraki, Ebrahim Abiri","doi":"10.1002/sia.7346","DOIUrl":"https://doi.org/10.1002/sia.7346","url":null,"abstract":"In this paper, a perfect absorber (PA) based on tungsten is proposed to include hexagonal‐shaped metasurface absorbers with varying hole sizes ranging from quadrangular to circular, allowing them to cover a wide wavelength spectrum. The study investigates the effects of various parameters, including the number of sides of the inner hole, on the absorber's performance and identifies the most suitable absorber by introducing an equivalent circuit. The outcomes of full‐wave numerical simulations primarily based on the finite element method (FEM) highly correspond to the final results of the circuit model. Additionally, the circuit model significantly reduces computation time and requires less storage compared with full‐wave simulations. The results show that the hexagonal‐square metasurface absorber achieves exceptional absorption rates, with an average of 99.9% in the 431 to 532 nm wavelength range and over 90% in the 300 to 915 nm range. The hexagonal‐hexagonal metasurface absorber also exhibits high absorption rates, with an average of over 99% in the 431 to 518 nm and 700 to 780 nm ranges, and over 90% in the 300 to 940 nm range. The absorption performance of the proposed hexagonal‐circle metasurface absorber is also remarkable, with an absorption value of over 99% in the 670 to 771 nm range and above 90% in the 365 to 991 nm range. These models can be utilized to design and simulate other subwavelength absorbers in a broad frequency range, including terahertz and visible light, making them suitable for various applications.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969366","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}
Jennifer Stefani Weber, Michael Cristian Goldbeck, Vanessa Piroli, Carla Daniela Boeira, Bruna Louise Perotti, Newton Kiyoshi Fukumasu, Fernando Alvarez, Alexandre Fassini Michels, Carlos Alejandro Figueroa
Diamond‐like carbon (DLC) is an amorphous material widely used in industrial applications due to its chemical, mechanical, and tribological properties and, also, for decorative purposes. However, its low adhesion to ferrous alloys reduces its effectiveness in certain applications, necessitating the use of adhesion interlayers to reduce stresses at the interfaces and enhance the density of strong bonds. In this context, the factors that promote good adhesion in this system and specify the parameters must be understood in detail. Thus, the present study aims to assess the influence of the base pressure on the deposition of an amorphous silicon carbide adhesion interlayer between DLC coating and a ferrous alloy substrate. Microstructural, physicochemical, morphological, and mechanotribological analyses were conducted to understand the adhesion behavior in terms of structural and chemical aspects. In addition to the influence of the interlayer thickness, the elemental Si/C ratios and the relative oxygen content have an impact on the maximum load supported by the coatings, as well as the different delamination mechanisms generated in adhesion tests.
{"title":"Influence of the base pressure in deposition of a‐SiCx interlayers for adhesion of Diamond‐Like Carbon on metallic alloy","authors":"Jennifer Stefani Weber, Michael Cristian Goldbeck, Vanessa Piroli, Carla Daniela Boeira, Bruna Louise Perotti, Newton Kiyoshi Fukumasu, Fernando Alvarez, Alexandre Fassini Michels, Carlos Alejandro Figueroa","doi":"10.1002/sia.7345","DOIUrl":"https://doi.org/10.1002/sia.7345","url":null,"abstract":"Diamond‐like carbon (DLC) is an amorphous material widely used in industrial applications due to its chemical, mechanical, and tribological properties and, also, for decorative purposes. However, its low adhesion to ferrous alloys reduces its effectiveness in certain applications, necessitating the use of adhesion interlayers to reduce stresses at the interfaces and enhance the density of strong bonds. In this context, the factors that promote good adhesion in this system and specify the parameters must be understood in detail. Thus, the present study aims to assess the influence of the base pressure on the deposition of an amorphous silicon carbide adhesion interlayer between DLC coating and a ferrous alloy substrate. Microstructural, physicochemical, morphological, and mechanotribological analyses were conducted to understand the adhesion behavior in terms of structural and chemical aspects. In addition to the influence of the interlayer thickness, the elemental Si/C ratios and the relative oxygen content have an impact on the maximum load supported by the coatings, as well as the different delamination mechanisms generated in adhesion tests.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784866","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}
We report the detailed depth‐dependent structural and chemical analysis of the Cr2O3/Cr bilayer structure deposited on Si ˂100˃ substrate. The non‐destructive simultaneous X‐ray reflectivity and grazing incidence X‐ray fluorescence measurements were used for this purpose. Corresponding variation in the chemical state of Cr atoms as a function of depth has been studied using X‐ray standing wave (XSW) assisted X‐ray absorption near edge structure (XANES) measurements. Various oxidation states of Cr atoms present in the Cr2O3/Cr bilayer structure were determined using X‐ray photoelectron spectroscopy (XPS). Depth‐resolved XANES measurements confirmed the presence of chromium oxide (Cr2O3) and hydroxide (Cr (OH)3) at the top surface of the Cr2O3/Cr bilayer structure. The results also reveal the presence of metallic Cr along with its compounds Cr2O3 and Cr (OH)3 at the interface medium, showing significant mixing between the Cr2O3 and Cr layers. Our results clearly demonstrate that the XSW assisted XANES technique is extremely efficient for determining the variation of chemical states at the surface, interface, and different depths of a thin film structure. Such types of analysis are particularly useful for differentiating the presence of a metal from its own oxides, even at higher depths inside a thin film medium.
我们报告了沉积在硅˂100˃基底上的 Cr2O3/Cr 双层结构的详细深度依赖性结构和化学分析。为此，我们采用了非破坏性的 X 射线反射率和掠入射 X 射线荧光同步测量法。利用 X 射线驻波（XSW）辅助 X 射线吸收近边缘结构（XANES）测量，研究了铬原子化学状态随深度的相应变化。利用 X 射线光电子能谱 (XPS) 测定了 Cr2O3/Cr 双层结构中存在的铬原子的各种氧化态。深度分辨 XANES 测量证实，在 Cr2O3/Cr 双层结构的顶层表面存在氧化铬 (Cr2O3) 和氢氧化物 (Cr (OH)3)。结果还显示，在界面介质中存在金属铬及其化合物 Cr2O3 和 Cr (OH)3，表明 Cr2O3 层和 Cr 层之间存在显著的混合。我们的研究结果清楚地表明，XSW 辅助 XANES 技术对于确定薄膜结构表面、界面和不同深度的化学状态变化极为有效。此类分析尤其有助于区分金属与其自身氧化物的存在，即使在薄膜介质的更深处也是如此。
{"title":"X‐ray standing wave assisted XANES for depth dependent chemical state analysis of Cr in Cr2O3/Cr bilayer structure","authors":"Ayushi Trivedi, Md. Akhlak Alam, Ajay Khooha, Rajnish Dhawan, Rajendra Kumar Sharma, Shilpa Tripathi, Manoj Kumar Tiwari","doi":"10.1002/sia.7342","DOIUrl":"https://doi.org/10.1002/sia.7342","url":null,"abstract":"We report the detailed depth‐dependent structural and chemical analysis of the Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Cr bilayer structure deposited on Si ˂100˃ substrate. The non‐destructive simultaneous X‐ray reflectivity and grazing incidence X‐ray fluorescence measurements were used for this purpose. Corresponding variation in the chemical state of Cr atoms as a function of depth has been studied using X‐ray standing wave (XSW) assisted X‐ray absorption near edge structure (XANES) measurements. Various oxidation states of Cr atoms present in the Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Cr bilayer structure were determined using X‐ray photoelectron spectroscopy (XPS). Depth‐resolved XANES measurements confirmed the presence of chromium oxide (Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>) and hydroxide (Cr (OH)<jats:sub>3</jats:sub>) at the top surface of the Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/Cr bilayer structure. The results also reveal the presence of metallic Cr along with its compounds Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> and Cr (OH)<jats:sub>3</jats:sub> at the interface medium, showing significant mixing between the Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> and Cr layers. Our results clearly demonstrate that the XSW assisted XANES technique is extremely efficient for determining the variation of chemical states at the surface, interface, and different depths of a thin film structure. Such types of analysis are particularly useful for differentiating the presence of a metal from its own oxides, even at higher depths inside a thin film medium.","PeriodicalId":22062,"journal":{"name":"Surface and Interface Analysis","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745559","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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