Photoelectron Spectroscopy

光电子能谱
  • 文章类型: Journal Article
    旋转失配二维(2D)异质结构中的莫尔电势已用于构建人造激子和电子晶格,它们已经成为实现奇特电子阶段的平台。这里,我们展示了一种通过使用极性分子阵列的近场在2D晶体中创建超晶格电势的不同方法。钛氧基酞菁(TiOPc)的双层,由交替的平面外偶极子组成,沉积在单层MoS2上。时间分辨双光子光发射光谱揭示了一对能量差0.1eV的层间激子状态,这与通过密度泛函理论计算确定的TiOPc双层引起的静电势调制一致。因为通过使用不同形状和大小的分子可以很容易地改变这种潜在超晶格的对称性和周期,分子/2D异质结构可以成为设计人工激子和电子晶格的有前途的平台。
    The moiré potential in rotationally misfit two-dimensional (2D) heterostructures has been used to build artificial exciton and electron lattices, which have become platforms for realizing exotic electronic phases. Here, we demonstrate a different approach to create a superlattice potential in 2D crystals by using the near field of an array of polar molecules. A bilayer of titanyl phthalocyanine (TiOPc), consisting of alternating out-of-plane dipoles, is deposited on monolayer MoS2. Time-resolved two-photon photoemission spectroscopy reveals a pair of interlayer exciton states with an energy difference of ∼0.1 eV, which is consistent with the electrostatic potential modulation induced by the TiOPc bilayer as determined by density functional theory calculations. Because the symmetry and the period of this potential superlattice can be changed readily by using molecules of different shapes and sizes, molecule/2D heterostructures can be promising platforms for designing artificial exciton and electron lattices.
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  • 文章类型: Journal Article
    表面生物官能化是制备任何影响其分析性能的生物测定的必要阶段。然而,生物功能化表面的完整表征,考虑到覆盖密度的研究,生物分子的分布和取向,层厚度,和目标生物识别效率,大部分时间都没有见面。这篇综述是对用于表征生物功能化表面及其之间过程的主要技术和策略的重要概述。重点是扫描力显微镜作为在实时动态实验中评估生物功能化表面质量的最通用和合适的工具,强调原子力显微镜的帮助,开尔文探针力显微镜,电化学原子力显微镜和光致力显微镜。其他技术,如光学和电子显微镜,石英晶体微天平,X射线光电子能谱,接触角,和电化学技术,还讨论了它们在解决生物改性表面的整个表征方面的优缺点。稀缺的评论指出了对生物功能化表面进行整个表征的重要性。这是第一个涵盖这一主题的评论,讨论了在任何开发用于检测临床和环境分析物的生物分析平台中应用的各种表征工具。此调查向分析师提供有关应用程序的信息,优势,以及这里讨论的技术的弱点,以从中提取出富有成果的见解。目的是促进和帮助分析人员完成对生物功能化表面的整个评估,并从获得的信息中获利,以提高生物分析产出。
    Surface biofunctionalization is an essential stage in the preparation of any bioassay affecting its analytical performance. However, a complete characterization of the biofunctionalized surface, considering studies of coverage density, distribution and orientation of biomolecules, layer thickness, and target biorecognition efficiency, is not met most of the time. This review is a critical overview of the main techniques and strategies used for characterizing biofunctionalized surfaces and the process in between. Emphasis is given to scanning force microscopies as the most versatile and suitable tools to evaluate the quality of the biofunctionalized surfaces in real-time dynamic experiments, highlighting the helpful of atomic force microscopy, Kelvin probe force microscopy, electrochemical atomic force microscopy and photo-induced force microscopy. Other techniques such as optical and electronic microscopies, quartz crystal microbalance, X-ray photoelectron spectroscopy, contact angle, and electrochemical techniques, are also discussed regarding their advantages and disadvantages in addressing the whole characterization of the biomodified surface. Scarce reviews point out the importance of practicing an entire characterization of the biofunctionalized surfaces. This is the first review that embraces this topic discussing a wide variety of characterization tools applied in any bioanalysis platform developed to detect both clinical and environmental analytes. This survey provides information to the analysts on the applications, strengths, and weaknesses of the techniques discussed here to extract fruitful insights from them. The aim is to prompt and help the analysts to accomplish an entire assessment of the biofunctionalized surface, and profit from the information obtained to enhance the bioanalysis output.
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  • 文章类型: Journal Article
    作为一项最有前途的环保技术,光催化效率的大幅提高仍然是实际应用的一大挑战。在这项工作中,Bi2O2CO3(BOC)纳米管的表面被Cl和I修饰。在不同的水热温度(T)下获得的样品被命名为T-X-BOC(X=Cl,I).X射线衍射(XRD)能量色散X射线(EDX)光谱和X射线光电子能谱(XPS)证明Cl和I仅化学吸附在BOC表面,而不是掺杂到晶格中。Cl和I的表面改性略微增加了光吸收范围,同时显着促进光电子从本体到表面的迁移,大大提高了载流子分离效率。密度泛函理论(DFT)计算进一步证明了表面Cl和I具有调节的能带结构和表面电荷分布。此外,表面Cl和I有利于O2吸附并捕获表面光电子,从而促进·O2-的形成;而表面Cl和I阻碍H2O的表面吸附,从而避免了•OH的产生。在罗丹明B(RhB)的降解中,孔和·O2-自由基起着至关重要的作用。在紫外光照射下(λ<420nm)45分钟,超过150-Cl-BOC(94%)和150-I-BOC(85%)的RhB降解率是原始BOC(18%)的4.2和3.7倍,分别。这项工作表明,简单的表面卤化改性大大提高了光催化活性。
    As a most promising environmental technology, the substantial enhancement of photocatalytic efficiency is still a big challenge for practical applications. In this work, the surface of Bi2O2CO3 (BOC) nanotubes are modified by Cl and I. The as-obtained samples at different hydrothermal temperatures (T) are designated as T-X-BOC (X = Cl, I). X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS) prove that Cl and I merely chemically adsorb on the BOC surface, rather than dope into the crystal lattice. The surface modification of Cl and I slightly increases light absorption range, while significantly promotes the photoelectron migration from bulk to the surface that greatly enhances the carrier separation efficiency. Density functional theory (DFT) calculations further prove that surface Cl and I have adjusted band structure and surface charge distribution. Besides, the surface Cl and I favor the O2 adsorption and trap the surface photoelectrons, thus promoting the formation of •O2-; while the surface Cl and I impede the surface adsorption of H2O, thus refraining the generation of •OH. In the degradation of rhodamine B (RhB), holes and •O2- radicals play the crucial role. Under ultraviolet light irradiation (λ < 420 nm) for 45 min, the RhB degradation ratios over 150-Cl-BOC (94%) and 150-I-BOC (85%) are 4.2 and 3.7 times higher than that of original BOC (18%), respectively. This work demonstrates that the simple surface halogenation modification greatly improves the photocatalytic activity.
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  • 文章类型: Journal Article
    OBJECTIVE: The aim of this study was to evaluate the effects of collagen modification on the osteogenic performance of different surface-modified titanium, including alkaline etching, alkaline etching followed by silanization, and alkaline etching followed by dopamine modification. The proliferation, adhesion, and osteogenic differentiation abilities of MC3T3-E1 cells on the surfaces with collagen modification were analyzed and compared.
    METHODS: Collagen was immobilized on the surfaces of pure titanium (Ti-C), alkaline-etched titanium (Ti-Na-C), alkaline-etched and silanized titanium (Ti-A-C), and alkaline-etched and dopamine-modified titanium (Ti-D-C), with pure titanium (Ti) as the control group. The surface morphology was observed by scanning electron microscopy (SEM), and the surface elemental composition was analyzed by X-ray photoelectron spectroscopy (XPS). Contact angle measurements were conducted to evaluate the hydrophilicity of the surfaces. MC3T3-E1 cells were cultured on the surfaces, and their proliferation, adhesion, and osteogenic differentiation abilities were assessed using CCK-8 assay, laser scanning confocal microscope, alkaline phosphatase (ALP) staining, Alizarin red staining and quantitative analysis, as well as real-time quantitative polymerase chain reaction (RT-qPCR) to evaluate the mRNA expression levels of osteogenic-related genes, including ALP, typeⅠcollagen (COL-1), osteocalcin (OCN), osteopontin (OPN).
    RESULTS: SEM and XPS results confirmed the successful immobilization of collagen on the titanium surfaces, with the Ti-Na-C group exhibiting a higher amount of collagen modification. Contact angle measurements showed improved hydrophilicity of the surfaces after collagen modification. CCK-8 results indicated good compatibility of the materials with MC3T3-E1, with enhanced cell proliferation on the collagen-modified surfaces. Cell fluorescence staining revealed better cell spreading on the collagen-modified surfaces, and ALP and Alizarin red staining results suggested that the Ti-Na-C group exhibited the best osteogenic performance, with significantly higher absorbance values in the Alizarin red quantification analysis. RT-qPCR analysis showed that the Ti-Na-C group had the highest expression of the osteogenic-related gene OPN.
    CONCLUSIONS: Among the different collagen modification approaches employed in this study, collagen modification on alkaline-etched titanium surfaces showed the most conducive effects on MC3T3-E1 cell adhesion, spreading, proliferation, and osteogenic differentiation. This approach can be considered as the optimal collagen modification strategy for enhancing osteogenesis on titanium surfaces.
    目的: 对纯钛表面分别进行碱蚀、碱蚀后硅烷化、碱蚀后多巴胺修饰等不同方式改性后在其表面制备生物胶原蛋白涂层,评价钛表面不同改性处理后胶原修饰的方案对细胞增殖黏附与成骨分化能力的影响。方法: 胶原蛋白通过交联剂作用附着于纯钛(Ti-C)、碱蚀钛片(Ti-Na-C)、碱蚀后硅烷化修饰钛片(Ti-A-C)及碱蚀后多巴胺修饰钛片表面(Ti-D-C),以纯钛为对照组。采用扫描电子显微镜(SEM)观察材料表面微形貌,X射线光电子能谱仪(XPS)分析材料表面元素组成,表面接触角测量仪评估材料表面亲水性。体外培养MC3T3-E1细胞,通过CCK-8、激光共聚焦显微镜、碱性磷酸酶(ALP)活性检测、茜素红染色及定量检测评价材料表面成骨细胞的增殖黏附与成骨分化能力,实时定量聚合酶链反应(RT-qPCR)检测成骨相关基因ALP、Ⅰ型胶原蛋白(COL-1)、骨钙素(OCN)、骨桥蛋白(OPN)的mRNA表达水平。结果: SEM与XPS结果表明胶原已成功修饰于钛片表面,Ti-Na-C组有较厚的胶原纤维层覆盖。表面接触角测量结果显示,除了Ti-Na-C组与Ti-Na组的接触角差异无统计学意义,其余胶原修饰后的材料表面具有更好的亲水性。CCK-8结果显示各组材料均无明显细胞毒性,胶原修饰后的材料表面成骨细胞增殖高于相应的未经胶原修饰材料;共聚焦显微镜检测结果可见,胶原修饰后材料表面细胞铺展面积更大;ALP染色与茜素红染色结果均提示,Ti-Na-C组体外成骨效果最佳,茜素红定量结果显示Ti-Na-C组吸光度值最高;RT-qPCR检测结果显示Ti-Na-C组的OPN基因表达量最高。结论: 在碱蚀、碱蚀后硅烷化、碱蚀后多巴胺修饰等对钛表面进行不同改性处理后修饰胶原的方案中,钛表面经过碱蚀处理后直接修饰胶原的方法最有利于MC3T3-E1黏附铺展、增殖与成骨分化,可作为胶原修饰的方案。.
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  • 文章类型: Journal Article
    在这项研究中,通过在生物炭表面掺杂Fe3O4合成磁性生物炭,然后分析其性能。评估了通过吸附和光解组合过程去除亚甲基蓝(MB)的效率。使用拉曼光谱和X射线光电子能谱证实了生物炭表面上Fe3O4的存在。磁性生物炭,MB吸附后,表现出39.50emu/g的磁性,回收率为97.07%。生物炭的比表面积(380.68m2/g)高于磁性生物炭(234.46m2/g),在最佳吸附条件下,生物炭对MB的最大吸附量(0.03mg/g)高于磁性生物炭对MB的最大吸附量(0.02mg/g)。使用生物炭或磁性生物炭的MB吸附实验在10-20mg/LMB浓度下进行。1克生物炭用量,pH值12,转速200转/分,温度25°C,和30分钟的持续时间。在黑暗条件下,生物炭具有较高的MB去除率,83.91%,与磁性生物炭相比,78.30%。在可见光下(λ>425nm),磁性生物炭在10分钟内有效去除MB,突出了吸附和光解的协同作用。根据吸附行为,MB被单层物理和化学吸附在EB和EMB的表面上。
    In this study, magnetic biochar was synthesized by doping Fe3O4 onto the biochar surface followed by analysis of its properties. The efficiency of methylene blue (MB) removal through the combined processes of adsorption and photolysis was assessed. The presence of Fe3O4 on the biochar surface was confirmed using Raman spectroscopy and X-ray photoelectron spectroscopy. The magnetic biochar, after MB adsorption, showed a magnetism of 39.50 emu/g leading to a 97.07 % recovery rate. The specific surface area of biochar was higher (380.68 m2/g) than that of magnetic biochar (234.46 m2/g), and the maximum adsorption capacity of MB was higher in the biochar (0.03 mg/g) than that in magnetic biochar (0.02 mg/g) under the optimal conditions for MB adsorption. The MB adsorption experiments using biochar or magnetic biochar were optimally conducted under 10-20 mg/L MB concentration, 1 g biochar dosage, pH 12, 200 rpm rotation speed, 25 °C temperature, and 30 min duration. Under dark conditions, biochar had a higher MB removal rate, at 83.91 %, compared to magnetic biochar, at 78.30 %. Under visible light (λ > 425 nm), magnetic biochar effectively removed MB within 10 min, highlighting the synergistic effect of adsorption and photolysis. MB is physically and chemically adsorbed by the monolayer on the surface of EB and EMB according to adsorption behavior.
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  • 文章类型: Journal Article
    有效去除水中的磷酸盐对于防止水体富营养化和水质恶化至关重要。本研究旨在通过合成淀粉稳定的锰铁二元氧化物(FMBO-S)来提高磷酸盐的去除,发现因素,并研究吸附机理。使用扫描电子显微镜研究了FMBO和FMBO-S的性质,BET分析,多分散指数(PDI),傅里叶变换红外光谱,和X射线光电子能谱(XPS)。淀粉加载后,平均孔径从14.89µ增加到25.16µ,并显着增加了中孔区域的孔体积。FMBO-S显示低于0.5的PDI值,表明均匀的尺寸分散性,并显示更快和更高的吸附容量:61.24mgg-1>28.57mgg-1。FMBO和FMBO-S吸附数据均与伪二阶和Freundlich模型拟合良好,表明化学吸附和多层吸附过程。FMBO对磷酸盐的吸附具有pH依赖性,表明静电吸引是主导机制。对于FMBO-S来说,在宽pH范围内有利于磷酸盐的吸附,尽管从零电荷和zeta电位值的角度来看静电吸引力较弱,表明配体交换是主要机制。此外,XPS分析表明,在磷酸盐吸附后,FMBO-S的Fe物种比例比FMBO显著变化,表明Fe的显著参与。同时,磷酸盐吸附几乎不受Cl-存在的影响,NO3-,和SO42-阴离子,而CO32-显著降低了吸附容量。这项研究表明,FMBO-S可能是一个有希望的,从水中去除和回收磷酸盐的低成本吸附剂。
    Effective removal of phosphate from water is essential for preventing the eutrophication and worsening of water quality. This study aims to enhance phosphate removal by synthesizing starch-stabilized ferromanganese binary oxide (FMBO-S), discover the factors, and investigate adsorption mechanisms. FMBO and FMBO-S properties were studied using Scanning Electron Microscopy, BET analysis, Polydispersity Index (PDI), Fourier Transform Infrared Spectroscopy, and X-ray Photoelectron Spectroscopy (XPS). After starch loading, the average pore diameter increased from 14.89 Å to 25.16 Å, and significantly increased the pore volume in the mesopore region. FMBO-S showed a PDI value below 0.5 indicating homogeneous size dispersity and demonstrated faster and higher adsorption capacity: 61.24 mg g-1 > 28.57 mg g-1. Both FMBO and FMBO-S adsorption data fit well with the pseudo-second-order and Freundlich models, indicating a chemisorption and multilayered adsorption process. The phosphate adsorption by FMBO was pH-dependent, suggesting electrostatic attraction as the dominant mechanism. For the FMBO-S, phosphate adsorption was favored in a wide pH range, despite the weaker electrostatic attraction as evident from the point of zero charge and zeta potential values, indicating ligand exchange as a main mechanism. Moreover, the XPS analysis shows a significant change in the proportion of Fe species for FMBO-S than FMBO after phosphate adsorption, indicating significant involvement of Fe. Meanwhile, phosphate adsorption was almost unaffected by the presence of Cl-, NO3-, and SO42- anions, whereas CO32- significantly reduced the adsorption capacity. This study revealed that FMBO-S could be a promising, low-cost adsorbent for phosphate removal and recovery from water.
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  • 文章类型: Journal Article
    本工作的重点是通过氧钒酞菁(VOPC)的热分解合成氮化钒(VN)/碳纳米复合材料。利用扫描电子显微镜(SEM)对合成化合物的形貌和化学结构进行了表征,透射电子显微镜(TEM),能量色散谱(EDS),傅里叶变换红外光谱(FTIR),X射线衍射(XRD)和X射线光发射光谱(XPS)。使用FTIR和XRD证实了VOPC和非金属化酞菁(H2PC)前体的成功合成。VN颗粒在通过溶胶-凝胶法合成的VN中呈现针状形态。VN/C复合材料的形态呈现小的VN颗粒簇。热分解的VOPC的XRD分析表明,无定形碳和VN纳米颗粒(VN(TD))的混合物具有与VN一致的空间群FM-3M的立方结构。XPS结果证实在所得材料中存在V(III)-N键,表明VN/C纳米复合材料的形成。通过热分解合成的VN/C纳米复合材料表现出高碳含量和VN颗粒的簇状分布。VN/C纳米复合材料用作LIB的阳极材料,100次循环后的比容量为307mAhg-1,第100次循环时的库仑效率为99.8。
    The present work focuses on the synthesis of a vanadium nitride (VN)/carbon nanocomposite material via the thermal decomposition of vanadyl phthalocyanine (VOPC). The morphology and chemical structure of the synthesized compounds were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS). The successful syntheses of the VOPC and non-metalated phthalocyanine (H2PC) precursors were confirmed using FTIR and XRD. The VN particles present a needle-like morphology in the VN synthesized by the sol-gel method. The morphology of the VN/C composite material exhibited small clusters of VN particles. The XRD analysis of the thermally decomposed VOPC indicated a mixture of amorphous carbon and VN nanoparticles (VN(TD)) with a cubic structure in the space group FM-3M consistent with that of VN. The XPS results confirmed the presence of V(III)-N bonds in the resultant material, indicating the formation of a VN/C nanocomposite. The VN/C nanocomposite synthesized through thermal decomposition exhibited a high carbon content and a cluster-like distribution of VN particles. The VN/C nanocomposite was used as an anode material in LIBs, which delivered a specific capacity of 307 mAh g-1 after 100 cycles and an excellent Coulombic efficiency of 99.8 at the 100th cycle.
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  • 文章类型: Journal Article
    这项研究提出了使用超声辅助水热合成技术的直接Z方案Y2TmSbO7/GdYBiNbO7异质结光催化剂(YGHP)的开创性合成。此外,新型光催化纳米材料,Y2TmSbO7和GdYBiNbO7是通过水热制造技术制造的。全面的表征技术,包括X射线衍射,傅里叶变换红外光谱,拉曼光谱,紫外可见分光光度法,X射线光电子能谱,透射电子显微镜,X射线能量色散光谱,荧光光谱法,光电流测试,电化学阻抗谱,紫外光电子能谱,和电子顺磁共振,被用来彻底调查形态特征,composition,化学,光学,和制备的样品的光电性能。在可见光暴露下,在农药乙草胺(AC)的降解和总有机碳(TOC)的矿化中评估了YGHP的光催化性能,展示了巨大的去除效率。具体来说,AC和TOC的去除率分别为99.75%和97.90%,分别。比较分析表明,与Y2TmSbO7,GdYBiNbO7或N掺杂的TiO2光催化剂相比,YGHP对AC的去除效率显着提高,去除率为1.12倍,1.21倍,或3.07倍,分别。同样,YGHP对TOC的去除效率明显高于上述光催化剂,去除率为1.15倍,1.28倍,或者高出3.51倍,分别。这些改进可以归因于Z方案电荷转移配置,保留了Y2TmSbO7和GdYBiNbO7较好的氧化还原容量。此外,YGHP的稳定性和耐久性得到证实,肯定其实际应用的潜力。捕获实验和电子自旋共振分析确定了YGHP产生的活性物种,即•OH,•O2-,和h+,允许对AC的降解机制和途径进行全面分析。总的来说,这项调查促进了高效Z方案异质结构材料的开发,并为制定可持续的治理策略以对抗AC污染提供了宝贵的见解。
    This study presents a pioneering synthesis of a direct Z-scheme Y2TmSbO7/GdYBiNbO7 heterojunction photocatalyst (YGHP) using an ultrasound-assisted hydrothermal synthesis technique. Additionally, novel photocatalytic nanomaterials, namely Y2TmSbO7 and GdYBiNbO7, were fabricated via the hydrothermal fabrication technique. A comprehensive range of characterization techniques, including X-ray diffractometry, Fourier-transform infrared spectroscopy, Raman spectroscopy, UV-visible spectrophotometry, X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray energy-dispersive spectroscopy, fluorescence spectroscopy, photocurrent testing, electrochemical impedance spectroscopy, ultraviolet photoelectron spectroscopy, and electron paramagnetic resonance, was employed to thoroughly investigate the morphological features, composition, chemical, optical, and photoelectric properties of the fabricated samples. The photocatalytic performance of YGHP was assessed in the degradation of the pesticide acetochlor (AC) and the mineralization of total organic carbon (TOC) under visible light exposure, demonstrating eximious removal efficiencies. Specifically, AC and TOC exhibited removal rates of 99.75% and 97.90%, respectively. Comparative analysis revealed that YGHP showcased significantly higher removal efficiencies for AC compared to the Y2TmSbO7, GdYBiNbO7, or N-doped TiO2 photocatalyst, with removal rates being 1.12 times, 1.21 times, or 3.07 times higher, respectively. Similarly, YGHP demonstrated substantially higher removal efficiencies for TOC than the aforementioned photocatalysts, with removal rates 1.15 times, 1.28 times, or 3.51 times higher, respectively. These improvements could be attributed to the Z-scheme charge transfer configuration, which preserved the preferable redox capacities of Y2TmSbO7 and GdYBiNbO7. Furthermore, the stability and durability of YGHP were confirmed, affirming its potential for practical applications. Trapping experiments and electron spin resonance analyses identified active species generated by YGHP, namely •OH, •O2-, and h+, allowing for comprehensive analysis of the degradation mechanisms and pathways of AC. Overall, this investigation advances the development of efficient Z-scheme heterostructural materials and provides valuable insights into formulating sustainable remediation strategies for combatting AC contamination.
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  • 文章类型: Journal Article
    在目前的工作中,马鞭草(VO)叶提取物被用作潜在的缓蚀剂,用于在0.5MH2SO4介质中腐蚀碳钢(CS)。Further,使用质量损失(ML)评估VO叶提取物对CS的腐蚀抑制性质,动电位极化(PDP),使用原子力显微镜(AFM)和X射线光电子能谱(XPS)技术进行电阻抗谱(EIS)和表面形态分析。使用阿伦尼乌斯方程计算活化能Ea*显示,在0.5MH2SO4培养基中添加VO叶提取物时,活化能增加,对于1000mgL-1VO叶提取物,观察到最大活化能(Ea*=49.9kJmol-1)在酸性培养基中。负自由能值表明CS表面上VO叶提取物吸附层的自发和稳定性。使用EIS测量,对于1000ppm溶液,实现了91.1%的高百分比抑制效果。随着VO叶提取物剂量的增加,双层电容(Cdl)值下降,而电荷转移(Rct)值增加。这表明在CS表面上形成了VO叶提取物的保护层。极化曲线表明,VO叶提取物作为混合型抑制剂。发现粘附在CS表面的VO叶提取物分子的吸附遵循Langmuir等温线。一些表面技术充分证明了VO叶提取物的防腐蚀作用。
    In the present work, Verbena Officinalis (VO) leaf extract was used as potential corrosion inhibitor for the corrosion of carbon steel (CS) in 0.5 M H2SO4 medium. Further, the corrosion inhibiting nature of VO leaf extract towards the CS was evaluated using mass loss (ML), potentiodynamic polarization (PDP), electrical impedance spectroscopy (EIS) and surface morphological analyses using atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS) techniques. Calculation of activation energy E a ∗ using Arrhenius equation shows the increase in activation energy when adding the VO leaf extract in 0.5 M H2SO4 medium and the maximum activation energy ( E a ∗  = 49.9 kJ mol-1) was observed for 1000 mg L-1 VO leaf extract in acid medium. The negative free energy values suggested the spontaneous and the stability of the adsorbed layer of VO leaf extract on the CS surface. Using EIS measurements, high percent inhibitory effectiveness of 91.1% for 1000 ppm solutions was achieved. With an increase in VO leaf extract dose, the double layer capacitance (Cdl) values fall while the values of charge transfer (Rct) increase. This showed that a protective layer of VO leaf extract on CS surface was formed. The polarization curves showed that the VO leaf extract acts as a mixed-type inhibitor. It is discovered that the adsorption of VO leaf extract molecules adhering to the CS surface followed the Langmuir isotherm. The anti-corrosion action of VO leaf extract is fully demonstrated by some surface techniques.
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  • 文章类型: Journal Article
    氧化铜纳米片(CuONSs)已成功地通过利用一种有效的一步方法的制糖方法,然后煅烧获得。通过X射线粉末衍射(XRD)等几种技术对纳米片进行了表征,透射电子显微镜(TEM),X射线光电子能谱(XPS)和傅里叶变换红外光谱(FTIR)。令人印象深刻的是,CuONSs表现出类似卤过氧化物酶(HPO)的催化活性,可催化H2O2对氯离子的氧化,从而产生反应性氯物种(RCS)。然后通过显色底物3,3'的氧化证明了灵敏和选择性的比色传感器,5,5'-四甲基联苯胺(TMB)通过新型纳米酶CuONSs产生用于H2O2和葡萄糖检测的RCS,检出限为109nM和21nM,线性范围分别为4.6µM至769µM和0.22µM至19.57µM。此外,该方法在实际样品中的葡萄糖分析中得到了验证。
    Copper oxide nanosheets (CuO NSs) have been successfully obtained by exploiting an effective one-step approach of sugar-blowing method followed by calcination. The nanosheets were characterized by several techniques like X-ray powder diffraction (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Impressively, CuO NSs display haloperoxidase (HPO) like catalytic activity which catalyses the oxidation of chloride ions by H2O2 giving rise to reactive chlorine species (RCS). A sensitive and selective colorimetric sensor was then demonstrated via the oxidation of chromogenic substrate 3,3\',5,5\'- tetramethylbenzidine (TMB) by the novel nanoenzyme CuO NSs through the generation of RCS for H2O2 and glucose detection with limit of detection of 109 nM and 21 nM in the linear ranges of 4.6 µM to 769 µM and 0.22 µM to 19.57 µM respectively. Additionally, the methodology is validated for the analysis of glucose in real samples.
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