Pub Date : 2024-11-25DOI: 10.1016/j.apsadv.2024.100656
Setareh Moradi, Roya Mozafari, Mohammad Ghadermazi
In this work, a novel procedure for the synthesis of magnetic porous polymer of γ-Fe2O3 by the immobilization of copper (CuSO44H2O) coated with pyridine-2,6-di carbonyl-bis(thiourea) as a cross-linker was accomplished in order to fabricate three dimensional. The heterogeneous nanocatalystγ-Fe2O3-Cu@Calix/pyridine-2,6-dicarbonyl-bis(thiourea)was characterized by Transmission electron microscopies (TEM), Field emission scanning electron microscopy (SEM), Energy-dispersive X-ray spectrometer (EDS), Fourier transform infrared spectroscopy (FT-IR), Powder X-raydiffraction (XRD), Vibrating-sample magnetometer (VSM), Thermal gravimetric analysis (TGA), Atomic Force Microscopy (AFM),Inductively coupled Plasma (ICP) and Nitrogen adsorption desorption isotherm (BET)techniques and was used for the synthesis of 2,4 disubstituted-1, 5-benzodiazepine through the reaction of various substituted α-epoxyketones with o-phenylenediamine under green conditions. Advantages of this protocol include the clean reaction conditions, short reaction times, simple work-up, catalyst recyclability, environmental friendliness, suppression of side products, and stability during the reaction process.
本研究采用一种新的方法，以吡啶-2,6-二羰基-双(硫脲)为交联剂，通过固定铜(CuSO44H2O)来合成γ-Fe2O3磁性多孔聚合物，从而制造出三维的γ-Fe2O3磁性多孔聚合物。透射电子显微镜（TEM）、场发射扫描电子显微镜（SEM）、能量色散 X 射线光谱仪（EDS）、傅立叶变换红外光谱仪（FT-IR）、粉末 X 射线衍射仪（XRD）和振动样品磁力计（VSM）对异质纳米催化剂γ-Fe2O3-Cu@Calix/吡啶-2,6-二羰基-双（硫脲）进行了表征、在绿色条件下，通过各种取代的 α-环氧酮与邻苯二胺反应合成 2,4-二取代-1,5-苯并二氮杂卓。该方案的优点包括反应条件清洁、反应时间短、操作简单、催化剂可回收、环境友好、抑制副产物以及反应过程稳定。
{"title":"3D-network polymer supported bimetallic γ-Fe2O3/Cu nanoparticles: As a new magnetic nanocomposite for the synthesis of new series functionalized benzodiazepines","authors":"Setareh Moradi, Roya Mozafari, Mohammad Ghadermazi","doi":"10.1016/j.apsadv.2024.100656","DOIUrl":"10.1016/j.apsadv.2024.100656","url":null,"abstract":"<div><div>In this work, a novel procedure for the synthesis of magnetic porous polymer of γ-Fe<sub>2</sub>O<sub>3</sub> by the immobilization of copper (CuSO<sub>4</sub>4H<sub>2</sub>O) coated with pyridine-2,6-di carbonyl-bis(thiourea) as a cross-linker was accomplished in order to fabricate three dimensional. The heterogeneous nanocatalystγ-Fe<sub>2</sub>O<sub>3</sub>-Cu@Calix/pyridine-2,6-dicarbonyl-bis(thiourea)was characterized by Transmission electron microscopies (TEM), Field emission scanning electron microscopy (SEM), Energy-dispersive X-ray spectrometer (EDS), Fourier transform infrared spectroscopy (FT-IR), Powder X-raydiffraction (XRD), Vibrating-sample magnetometer (VSM), Thermal gravimetric analysis (TGA), Atomic Force Microscopy (AFM),Inductively coupled Plasma (ICP) and Nitrogen adsorption desorption isotherm (BET)techniques and was used for the synthesis of 2,4 disubstituted-1, 5-benzodiazepine through the reaction of various substituted α-epoxyketones with o-phenylenediamine under green conditions. Advantages of this protocol include the clean reaction conditions, short reaction times, simple work-up, catalyst recyclability, environmental friendliness, suppression of side products, and stability during the reaction process.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"25 ","pages":"Article 100656"},"PeriodicalIF":7.5,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-25DOI: 10.1016/j.apsadv.2024.100666
Sasimontra Timjan , Ta-Cheng Wei , Kuan-Han Lin , Yi-Ting Li , Po-Hsuan Hsiao , Chia-Yun Chen
The assessment of electron transport layer (ETL) for rear-contact engineering of silicon (Si) based optoelectronics has been considered as one of the critical challenges that leverage the performance improvement and device reliability. In this work, the hybrid design of ETL, obtained from the solution-processed nitrogen-doped carbon quantum dots (NCQDs) incorporated with organic polyethylenimine (PEI) demonstrates the feasible contact characteristics for the modification of Si/Al contacts, which greatly facilitates the transport and collection of photoexcited electrons in the Si-based optoelectronics. The aspects of microstructures, functional groups, chemical features, interfacial characteristics and band structures of NCQD/PEI are explicated, visualizing that the evolution of interface dipoles mediated by the overall outcome of physisorption and chemisorption effects, modifies the surface potential difference and results in the explicit reduction of the Al work function from 4.3 eV for pristine Al to 3.23 eV based on the optimized constitutional design (0.10 % NCQD in PEI). These findings are practically employed on the Si-based hybrid solar cells at Si/Al interfaces, fulfilling the conversion-efficiency improvement by 30.9 % compared with reference cells without ETL employment, which are experimentally interpreted by the efficient electron transport across the Si/Al heterojunction and charge collection.
用于硅基光电子学后接触工程的电子传输层（ETL）评估一直被认为是提高性能和器件可靠性的关键挑战之一。在这项工作中，由溶液加工的氮掺杂碳量子点（NCQDs）与有机聚乙烯亚胺（PEI）混合设计的 ETL 证明了改性硅/铝接触的可行接触特性，这极大地促进了硅基光电子中光激发电子的传输和收集。对 NCQD/PEI 的微观结构、官能团、化学特征、界面特性和能带结构等方面进行了阐述，表明界面偶极子在物理吸附和化学吸附效应总体结果的介导下发生了演变，从而改变了表面电势差，并根据优化的结构设计（0.10 % 的 NCQD 加入 PEI），使 Al 的功函数从原始 Al 的 4.3 eV 明显降低到 3.23 eV。这些发现被实际应用于硅/铝界面上的硅基混合太阳能电池，与未使用 ETL 的参考电池相比，转换效率提高了 30.9%。
{"title":"Interface dipole evolution from the hybrid coupling between nitrogen-doped carbon quantum dots and polyethylenimine featuring the electron transport thin layer at Al/Si interfaces","authors":"Sasimontra Timjan , Ta-Cheng Wei , Kuan-Han Lin , Yi-Ting Li , Po-Hsuan Hsiao , Chia-Yun Chen","doi":"10.1016/j.apsadv.2024.100666","DOIUrl":"10.1016/j.apsadv.2024.100666","url":null,"abstract":"<div><div>The assessment of electron transport layer (ETL) for rear-contact engineering of silicon (Si) based optoelectronics has been considered as one of the critical challenges that leverage the performance improvement and device reliability. In this work, the hybrid design of ETL, obtained from the solution-processed nitrogen-doped carbon quantum dots (NCQDs) incorporated with organic polyethylenimine (PEI) demonstrates the feasible contact characteristics for the modification of Si/Al contacts, which greatly facilitates the transport and collection of photoexcited electrons in the Si-based optoelectronics. The aspects of microstructures, functional groups, chemical features, interfacial characteristics and band structures of NCQD/PEI are explicated, visualizing that the evolution of interface dipoles mediated by the overall outcome of physisorption and chemisorption effects, modifies the surface potential difference and results in the explicit reduction of the Al work function from 4.3 eV for pristine Al to 3.23 eV based on the optimized constitutional design (0.10 % NCQD in PEI). These findings are practically employed on the Si-based hybrid solar cells at Si/Al interfaces, fulfilling the conversion-efficiency improvement by 30.9 % compared with reference cells without ETL employment, which are experimentally interpreted by the efficient electron transport across the Si/Al heterojunction and charge collection.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"25 ","pages":"Article 100666"},"PeriodicalIF":7.5,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-23DOI: 10.1016/j.apsadv.2024.100662
P. Slepička , N. Slepičková Kasálková , J. Musílková , L. Bačáková , B. Frýdlová , P. Sajdl , Z. Kolská , E. Rebollar , V. Švorčík
In this study, we constructed and activated honeycomb structures on perfluorinated substrates subjected to KrF laser treatment (wavelength 248 nm). We selected the biopolymer poly L-lactic acid (PLLA) as the honeycomb material, which was dissolved in a mixture of chloroform/methanol. A micropattern of a plasma-treated perfluorethyleneperopylene (FEP) substrate was prepared by improved phase separation during dip-coating. The PLLA micropattern was subsequently treated with an excimer laser with a laser fluence of 10 mJ.cm-2 and with a different number of laser pulses. Alternatively, plasma exposure can be used as a secondary treatment. The surface morphologies of the pristine and laser-treated PLLA patterns were studied using atomic force and scanning electron microscopy. The surface chemistry was analyzed using energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. In addition, the metabolic activity of adipose stem cells was evaluated using the MTS test, and cell numbers in selected samples were determined. The morphology of cells growing in the honeycomb-like pattern was studied in detail using fluorescence microscopy. In all, we used a combination of honeycomb pattern (HCP) laser treatment and plasma treatment to construct an optimal scaffold for adipose stem cell culture.
{"title":"PLLA honeycombs activated by plasma and high-energy excimer laser for stem cell support","authors":"P. Slepička , N. Slepičková Kasálková , J. Musílková , L. Bačáková , B. Frýdlová , P. Sajdl , Z. Kolská , E. Rebollar , V. Švorčík","doi":"10.1016/j.apsadv.2024.100662","DOIUrl":"10.1016/j.apsadv.2024.100662","url":null,"abstract":"<div><div>In this study, we constructed and activated honeycomb structures on perfluorinated substrates subjected to KrF laser treatment (wavelength 248 nm). We selected the biopolymer poly L-lactic acid (PLLA) as the honeycomb material, which was dissolved in a mixture of chloroform/methanol. A micropattern of a plasma-treated perfluorethyleneperopylene (FEP) substrate was prepared by improved phase separation during dip-coating. The PLLA micropattern was subsequently treated with an excimer laser with a laser fluence of 10 mJ.cm<sup>-2</sup> and with a different number of laser pulses. Alternatively, plasma exposure can be used as a secondary treatment. The surface morphologies of the pristine and laser-treated PLLA patterns were studied using atomic force and scanning electron microscopy. The surface chemistry was analyzed using energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. In addition, the metabolic activity of adipose stem cells was evaluated using the MTS test, and cell numbers in selected samples were determined. The morphology of cells growing in the honeycomb-like pattern was studied in detail using fluorescence microscopy. In all, we used a combination of honeycomb pattern (HCP) laser treatment and plasma treatment to construct an optimal scaffold for adipose stem cell culture.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"25 ","pages":"Article 100662"},"PeriodicalIF":7.5,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-21DOI: 10.1016/j.apsadv.2024.100663
Haehyun Min , Ye Jin Ji , Do Yeong Kim , Yangguen Ju , Chang Geun Yoo , Young Jin Kim , Sung Bong Kang
The dry reforming of methane (DRM) is a promising catalytic reaction for converting greenhouse gases (CH4 and CO2) into valuable syngas. Despite the advantages of silica as a catalyst support, its inert nature limits its application in DRM due to reduced binding affinity with nickel. Here, we developed Ni-impregnated silica catalysts exhibiting a bimodal pore system in which silica supports were synthesized by tuning the ratio of aminopropyl triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS). The Ni/silica catalyst prepared by the intermediate concentration of APTES exhibited a unique combination of acidic and basic properties, enhancing DRM activity and catalytic durability. The catalysts displayed a favorable nickel size distribution, with smaller Ni particles in intermediate ratio silica, overcoming the limitations of conventional silica-based catalysts. Our findings demonstrate the suitable catalytic characteristics of Ni/synthesized-SiO2 for the dry reforming of methane.
{"title":"Steering catalytic property and reactivity of Ni/SiO2 by functionalized silica for dry reforming of methane","authors":"Haehyun Min , Ye Jin Ji , Do Yeong Kim , Yangguen Ju , Chang Geun Yoo , Young Jin Kim , Sung Bong Kang","doi":"10.1016/j.apsadv.2024.100663","DOIUrl":"10.1016/j.apsadv.2024.100663","url":null,"abstract":"<div><div>The dry reforming of methane (DRM) is a promising catalytic reaction for converting greenhouse gases (CH<sub>4</sub> and CO<sub>2</sub>) into valuable syngas. Despite the advantages of silica as a catalyst support, its inert nature limits its application in DRM due to reduced binding affinity with nickel. Here, we developed Ni-impregnated silica catalysts exhibiting a bimodal pore system in which silica supports were synthesized by tuning the ratio of aminopropyl triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS). The Ni/silica catalyst prepared by the intermediate concentration of APTES exhibited a unique combination of acidic and basic properties, enhancing DRM activity and catalytic durability. The catalysts displayed a favorable nickel size distribution, with smaller Ni particles in intermediate ratio silica, overcoming the limitations of conventional silica-based catalysts. Our findings demonstrate the suitable catalytic characteristics of Ni/synthesized-SiO<sub>2</sub> for the dry reforming of methane.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"24 ","pages":"Article 100663"},"PeriodicalIF":7.5,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.apsadv.2024.100660
Julianija Nikitina , Simonas Indrišiūnas , Tomas Tolenis , Mindaugas Andrulevicius , Lina Grineviciute
Nano- and micro-structuring of transparent glass for IR or visible spectrum applications is challenging due to low yield and slow processes, especially while maintaining high surface quality. The method proposed in this work involves the structuring and subsequent thermal oxidation of a thin metallic layer on a glass substrate. Annealing of the structured metal layer produces a transparent fully inorganic oxide surface with periodic patterns, avoiding the subtleties of glass structuring. A new method for the formation of sub-micrometer non-absorbing gratings with 750 nm periodicity is presented by direct laser interference patterning (DLIP) of thin tantalum layers on fused silica substrates followed by thermal oxidation by annealing. This method aims to improve the field of laser optics by providing a scalable and efficient method for the creation of precise metal-oxide photonic structures.
{"title":"Submicron periodic structures in metal oxide coating via laser ablation and thermal oxidation","authors":"Julianija Nikitina , Simonas Indrišiūnas , Tomas Tolenis , Mindaugas Andrulevicius , Lina Grineviciute","doi":"10.1016/j.apsadv.2024.100660","DOIUrl":"10.1016/j.apsadv.2024.100660","url":null,"abstract":"<div><div>Nano- and micro-structuring of transparent glass for IR or visible spectrum applications is challenging due to low yield and slow processes, especially while maintaining high surface quality. The method proposed in this work involves the structuring and subsequent thermal oxidation of a thin metallic layer on a glass substrate. Annealing of the structured metal layer produces a transparent fully inorganic oxide surface with periodic patterns, avoiding the subtleties of glass structuring. A new method for the formation of sub-micrometer non-absorbing gratings with 750 nm periodicity is presented by direct laser interference patterning (DLIP) of thin tantalum layers on fused silica substrates followed by thermal oxidation by annealing. This method aims to improve the field of laser optics by providing a scalable and efficient method for the creation of precise metal-oxide photonic structures.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"24 ","pages":"Article 100660"},"PeriodicalIF":7.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study successfully grew ꞵ-Ga2O3 epitaxial films on silicon carbide substrates by metalorganic chemical vapor deposition and fabricated vertical Schottky barrier diodes (SBDs), which were annealed in a high temperature furnace. The high surface roughness and oxygen vacancies of the unannealed device caused a large leakage current, thus three different annealing durations were used to repair the surface oxygen vacancies in an O2:N2=1:4 gas environment. The results showed that a 5-minute thermal annealing process was the most effective in repairing surface oxygen vacancies. According to the X-ray photoelectron spectroscopy spectra of the O 1 s core levels in Ga2O3 epilayers, the proportion of oxygen vacancies decreased from 56.56 % to 49.71 %. Additionally, the leakage current density was decreased from 10−3 to 10−5 A/cm2 and the surface roughness decreases to 32.6 nm due to stress release. Furthermore, the barrier heights (φb) of the SBDs without annealing, and after annealed for 5, 20, and 40 min were measured at 0.911, 1.229, 1.090, and 1.115 eV, respectively. It was observed that the SBD fabricated on the epilayer annealed for 5 min exhibited the lowest leakage current (approximately 2 × 10⁻⁵ A/cm²) and the highest breakdown voltage, measuring around 132 V.
{"title":"Study of thermal annealing on gallium oxide heteroepitaxial layers grown on SiC for vertical Schottky barrier diodes applications","authors":"Chai-Wei Ku , Sheng-Ti Chung , Fu-Gow Tarntair , Ching-Lien Hsiao , Ray-Hua Horng","doi":"10.1016/j.apsadv.2024.100661","DOIUrl":"10.1016/j.apsadv.2024.100661","url":null,"abstract":"<div><div>This study successfully grew ꞵ-Ga<sub>2</sub>O<sub>3</sub> epitaxial films on silicon carbide substrates by metalorganic chemical vapor deposition and fabricated vertical Schottky barrier diodes (SBDs), which were annealed in a high temperature furnace. The high surface roughness and oxygen vacancies of the unannealed device caused a large leakage current, thus three different annealing durations were used to repair the surface oxygen vacancies in an O<sub>2</sub>:N<sub>2</sub>=1:4 gas environment. The results showed that a 5-minute thermal annealing process was the most effective in repairing surface oxygen vacancies. According to the X-ray photoelectron spectroscopy spectra of the O 1 s core levels in Ga<sub>2</sub>O<sub>3</sub> epilayers, the proportion of oxygen vacancies decreased from 56.56 % to 49.71 %. Additionally, the leakage current density was decreased from 10<sup>−3</sup> to 10<sup>−5</sup> A/cm<sup>2</sup> and the surface roughness decreases to 32.6 nm due to stress release. Furthermore, the barrier heights (φ<sub>b</sub>) of the SBDs without annealing, and after annealed for 5, 20, and 40 min were measured at 0.911, 1.229, 1.090, and 1.115 eV, respectively. It was observed that the SBD fabricated on the epilayer annealed for 5 min exhibited the lowest leakage current (approximately 2 × 10⁻⁵ A/cm²) and the highest breakdown voltage, measuring around 132 V.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"24 ","pages":"Article 100661"},"PeriodicalIF":7.5,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.apsadv.2024.100659
Grzegorz Greczynski, Jun Lu, Vladyslav Rogoz, Lars Hultman
Sample charging during X-ray photoelectron spectroscopy analyses of electrically insulating samples is a widely recognized challenge of this essential technique. If the electron loss caused by the photoelectric effect is not compensated due to specimens’ poor electrical conductivity, the positive charge building up in the surface region results in an uncontrolled shift of detected core level peaks to higher binding energy (BE). This seriously complicates chemical bonding assignment, which is based on measured peak positions, and accounts for a large spread in reported core level BE values. Here, we show that peaks from several industry-relevant oxides, serving as model insulators, typically displaced by several eV due to charging, shift back to positions characteristic of electrically-neutral samples following ex-situ capping with a few nm thick metallic layer with low affinity to oxygen. The effect is present only if the capping layers contain sufficiently large non-oxidized volume that provides long-range conduction paths to grounded Cu clamps, while being thin enough to allow for recording high quality spectra from the underlying insulators. The versatility of the charging elimination is demonstrated for different oxides/cap combinations, air exposure times, and sample types (including thin film and bulk specimens).
在对电绝缘样品进行 X 射线光电子能谱分析时，样品充电是这一重要技术面临的公认挑战。如果由于试样导电性差而无法弥补光电效应造成的电子损耗，那么表面区域积累的正电荷就会导致检测到的核级峰值不受控制地向更高的结合能（BE）移动。这严重影响了根据测量到的峰值位置进行的化学键分配，并导致报告的核心水平 BE 值存在较大差异。在这里，我们展示了几种工业相关氧化物的峰值，作为模型绝缘体，这些峰值通常会因充电而偏移几个 eV，在原位封盖几纳米厚的与氧亲和力低的金属层后，这些峰值会移回电中性样品的特征位置。只有当封盖层含有足够大的非氧化体积，为接地的铜夹钳提供长程传导路径，同时又足够薄以允许从底层绝缘体记录高质量光谱时，才会出现这种效应。针对不同的氧化物/封盖组合、空气暴露时间和样品类型（包括薄膜和块状试样），演示了充电消除的多功能性。
{"title":"Eliminating surface charging in X-ray photoelectron spectroscopy of insulators for reliable bonding assignments","authors":"Grzegorz Greczynski, Jun Lu, Vladyslav Rogoz, Lars Hultman","doi":"10.1016/j.apsadv.2024.100659","DOIUrl":"10.1016/j.apsadv.2024.100659","url":null,"abstract":"<div><div>Sample charging during X-ray photoelectron spectroscopy analyses of electrically insulating samples is a widely recognized challenge of this essential technique. If the electron loss caused by the photoelectric effect is not compensated due to specimens’ poor electrical conductivity, the positive charge building up in the surface region results in an uncontrolled shift of detected core level peaks to higher binding energy (BE). This seriously complicates chemical bonding assignment, which is based on measured peak positions, and accounts for a large spread in reported core level BE values. Here, we show that peaks from several industry-relevant oxides, serving as model insulators, typically displaced by several eV due to charging, shift back to positions characteristic of electrically-neutral samples following <em>ex-situ</em> capping with a few nm thick metallic layer with low affinity to oxygen. The effect is present only if the capping layers contain sufficiently large non-oxidized volume that provides long-range conduction paths to grounded Cu clamps, while being thin enough to allow for recording high quality spectra from the underlying insulators. The versatility of the charging elimination is demonstrated for different oxides/cap combinations, air exposure times, and sample types (including thin film and bulk specimens).</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"24 ","pages":"Article 100659"},"PeriodicalIF":7.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-11DOI: 10.1016/j.apsadv.2024.100657
A․J․González Fá , P. Bechthold , A. Juan , J.M. Marchetti
Numerous studies have reported that the addition of glycerol at the onset of an oil transesterification reaction with methanol, catalyzed by CaO, significantly accelerates the reaction. The role of glycerol, which is also a reaction product, is not yet fully understood. The formation of glycerolate structures, in both solid and polymeric forms, has been proposed to actively contribute to the reaction rate. In previous works, we have simulated the formation of incipient OH and ethoxide species on the CaO during ethanol adsorption, and bidentate species between formic acid and the surface. In the present work we have investigated, using DFT-based simulations, the possible initial stages in the formation of glycerolate on CaO (001) surfaces. Our results indicate the bonding of two OHs from glycerol with the surface. We also detected the possible rupture of these OHs by a strong decrease in the bonding order (BO), up to 75%. At the same time, the formation of Oglycerol―Ca bonds and the decrease in the BO of the surface Ca―O bonds of up to 61% are detected. A charge transfer from the surface to the molecule is also observed. Additionally, a detailed analysis of the changes in the geometry and electronic structure of the glycerol and the surface before and after adsorption is conducted.
许多研究报告指出，在 CaO 催化下，在油类与甲醇发生酯交换反应之初加入甘油，可显著加快反应速度。甘油也是一种反应产物，其作用尚未完全明了。有人提出，固体和聚合物形式的甘油酸酯结构的形成对反应速率有积极的促进作用。在之前的研究中，我们模拟了乙醇吸附过程中在 CaO 上形成的初生 OH 和乙氧物种，以及甲酸与表面之间的双齿型物种。在本研究中，我们利用基于 DFT 的模拟研究了甘油酸盐在 CaO (001) 表面形成的可能初始阶段。我们的研究结果表明，甘油中的两个羟基与表面结合。我们还通过键合阶（BO）的强烈下降（高达 75%）检测到了这些羟基的可能断裂。同时，我们还检测到甘油-钙键的形成，以及表面 Ca-O 键的键序（BO）降低达 61%。还观察到电荷从表面转移到分子。此外，还对甘油和表面在吸附前后的几何和电子结构变化进行了详细分析。
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Titanium alloy implants release metallic ions into the bloodstream and high corrosion rate in physiological environment due to change in pH level. Here in, bio-ceramic HA coating and HA based binary composite coating (HA/TiO2 and HA/ZrO2) have been developed on Ti-6Al-4 V alloy for improvement in corrosion resistance and reduction in the metal ion release. In this study, HA, HA/TiO2, and HA/ZrO2 coating have been developed by using a 400 W, 1070 nm fiber laser cladding process. Microstructural characterization was performed using 3D-optical profilometer, FESEM, EDS, and XRD, while electrochemical properties were analyzed in simulated body fluid. The Ca/P ratio indicated HA decomposition into calcium phosphate during the laser process. Phase analysis identified α-Ti, Ca2P2O7, TiO2, and CaTiO3 in HA/TiO2 cladding, and α-Ti, Ca3(PO4)2, Ca2P2O7, TiO2, CaTiO3, and CaZrO3 in HA/ZrO2 cladding. The analysis revealed that HA-based composite cladding produced a more corrosion resistant surface as compared to HA cladding and Ti-6Al-4 V alloy. However, HA/TiO2 composite cladding significantly reduced corrosion current density, corrosion rate and increasing polarization resistance.
From the obtained results it is concluded that HA/ TiO2 and HA/ ZrO2 composite coating developed by laser cladding process, give cracks free structure and significantly decreased corrosion rate as compared to HA coating. This composite coating would be beneficial for improving orthopedic implant performance, and long-term durability.
钛合金植入物会向血液中释放金属离子，在生理环境中会因 pH 值变化而产生高腐蚀率。在此，我们在 Ti-6Al-4 V 合金上开发了生物陶瓷 HA 涂层和基于 HA 的二元复合涂层（HA/TiO2 和 HA/ZrO2），以提高耐腐蚀性并减少金属离子释放。在这项研究中，采用 400 W、1070 nm 光纤激光熔覆工艺开发了 HA、HA/TiO2 和 HA/ZrO2 涂层。使用三维光学轮廓仪、FESEM、EDS 和 XRD 进行了微结构表征，并在模拟体液中分析了电化学特性。Ca/P 比率表明 HA 在激光过程中分解为磷酸钙。相分析表明，在 HA/TiO2 包层中存在 α-Ti、Ca2P2O7、TiO2 和 CaTiO3；在 HA/ZrO2 包层中存在 α-Ti、Ca3(PO4)2、Ca2P2O7、TiO2、CaTiO3 和 CaZrO3。分析表明，与 HA 包层和 Ti-6Al-4 V 合金相比，HA 基复合包层产生了更耐腐蚀的表面。从获得的结果可以得出结论，与 HA 涂层相比，通过激光熔覆工艺开发的 HA/ TiO2 和 HA/ ZrO2 复合涂层具有无裂纹结构，并能显著降低腐蚀速率。这种复合涂层有利于提高骨科植入物的性能和长期耐久性。
{"title":"Microstructural characterization and corrosion analysis of HA/TiO2 and HA/ZrO2 composite coating on Ti- alloy by laser cladding","authors":"Renu Kumari , Sumit Kumar , Alok Kumar Das , Ananad Mohan Murmu , Kumari Kanchan","doi":"10.1016/j.apsadv.2024.100655","DOIUrl":"10.1016/j.apsadv.2024.100655","url":null,"abstract":"<div><div>Titanium alloy implants release metallic ions into the bloodstream and high corrosion rate in physiological environment due to change in pH level. Here in, bio-ceramic HA coating and HA based binary composite coating (HA/TiO<sub>2</sub> and HA/ZrO<sub>2</sub>) have been developed on Ti-6Al-4 V alloy for improvement in corrosion resistance and reduction in the metal ion release. In this study, HA, HA/TiO<sub>2</sub>, and HA/ZrO<sub>2</sub> coating have been developed by using a 400 W, 1070 nm fiber laser cladding process. Microstructural characterization was performed using 3D-optical profilometer, FESEM, EDS, and XRD, while electrochemical properties were analyzed in simulated body fluid. The Ca/P ratio indicated HA decomposition into calcium phosphate during the laser process. Phase analysis identified α-Ti, Ca<sub>2</sub>P<sub>2</sub>O<sub>7</sub>, TiO<sub>2</sub>, and CaTiO<sub>3</sub> in HA/TiO<sub>2</sub> cladding, and α-Ti, Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>, Ca<sub>2</sub>P<sub>2</sub>O<sub>7</sub>, TiO<sub>2</sub>, CaTiO<sub>3</sub>, and CaZrO<sub>3</sub> in HA/ZrO<sub>2</sub> cladding. The analysis revealed that HA-based composite cladding produced a more corrosion resistant surface as compared to HA cladding and Ti-6Al-4 V alloy. However, HA/TiO<sub>2</sub> composite cladding significantly reduced corrosion current density, corrosion rate and increasing polarization resistance.</div><div>From the obtained results it is concluded that HA/ TiO<sub>2</sub> and HA/ ZrO<sub>2</sub> composite coating developed by laser cladding process, give cracks free structure and significantly decreased corrosion rate as compared to HA coating. This composite coating would be beneficial for improving orthopedic implant performance, and long-term durability.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"24 ","pages":"Article 100655"},"PeriodicalIF":7.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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