Photoelectron Spectroscopy

光电子能谱
  • 文章类型: Journal Article
    羰基(C=O)在生物系统的光物理和光化学中起着至关重要的作用。O1sX射线光电子能谱可以有针对性地研究C=O基团,C=O振动与O1s电离之间的耦合反映在精细结构中。为了阐明其特有的振动特性,对六种常见的生物分子进行了系统的Franck-Condon模拟,包括三个嘌呤(黄嘌呤,咖啡因,和次黄嘌呤)和三个嘧啶(胸腺嘧啶,5F-尿嘧啶,和尿嘧啶)。这些生物分子的模拟的复杂性在于考虑温度效应和潜在的互变异构变化。我们结合了时间相关和时间无关的方法,以有效地说明温度影响并提供明确的分配,分别。对于次黄嘌呤,通过合并两种互变异构体的玻尔兹曼种群比来考虑互变异构效应.模拟与实验光谱表现出良好的一致性,能够区分具有细微局部结构差异的两种类型的羰基氧,位于两个氮(O1)之间或一个碳和一个氮(O2)之间。分析提供了对C=O振动和O1s电离之间耦合的见解,在O1s电离时,始终显示C=O键长的伸长(0.08-0.09µ)。
    Carbonyl groups (C=O) play crucial roles in the photophysics and photochemistry of biological systems. O1s x-ray photoelectron spectroscopy allows for targeted investigation of the C=O group, and the coupling between C=O vibration and O1s ionization is reflected in the fine structures. To elucidate its characteristic vibronic features, systematic Franck-Condon simulations were conducted for six common biomolecules, including three purines (xanthine, caffeine, and hypoxanthine) and three pyrimidines (thymine, 5F-uracil, and uracil). The complexity of simulation for these biomolecules lies in accounting for temperature effects and potential tautomeric variations. We combined the time-dependent and time-independent methods to efficiently account for the temperature effects and to provide explicit assignments, respectively. For hypoxanthine, the tautomeric effect was considered by incorporating the Boltzmann population ratios of two tautomers. The simulations demonstrated good agreement with experimental spectra, enabling differentiation of two types of carbonyl oxygens with subtle local structural differences, positioned between two nitrogens (O1) or between one carbon and one nitrogen (O2). The analysis provided insights into the coupling between C=O vibration and O1s ionization, consistently showing an elongation of the C=O bond length (by 0.08-0.09 Å) upon O1s ionization.
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  • 文章类型: Journal Article
    废水中铀的高效捕集对于环境修复和核能的可持续发展至关重要,然而,它带来了相当大的挑战。在这项研究中,插入到氧化石墨烯(GO)纳米片中的两亲性离子共价有机框架与聚乙烯亚胺(PEI)官能化用于构建具有超快铀吸附的杂化膜。这些杂化膜仅在10分钟内达到平衡,在pH=6时吸附能力高达358.8mgg-1。X射线光电子能谱(XPS)和密度泛函理论(DFT)分析表明,磺酸基团与铀酰离子之间的强相互作用是高吸附容量和选择性的主要原因。化学价的扩展过渡态和自然轨道(ETS-NOCV)分析表明,铀酰的7s和5f轨道与磺酸盐中S和O的2p轨道之间的相互作用是之间强相互作用的主要原因。磺酸盐和铀酰离子。该研究为从废水中快速提取铀提供了一种有效的方法。
    The efficient capture of uranium from wastewater is crucial for environmental remediation and the sustainable development of nuclear energy, yet it poses considerable challenges. In this study, amphiphilic ionic covalent organic framework intercalated into graphene oxide (GO) nanosheets functionalized with polyethyleneimine (PEI) were used to construct hybrid membranes with ultrafast uranium adsorption. These hybrid membranes achieved equilibrium in just 10 min and the adsorption capacity was as high as 358.8 mg g-1 at pH = 6. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) analyses revealed that the strong interaction between sulfonic acid groups and uranyl ions was the primary reason for the high adsorption capacity and selectivity. The extended transition state and natural orbitals for chemical valence (ETS-NOCV) analysis revealed that the interaction between the 7 s and 5f orbitals of uranyl and the 2p orbitals of S and O in the sulfonate was the primary reason for the strong interaction between the sulfonate and the uranyl ion. This research presents an effective method for the rapid extraction of uranium from wastewater.
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  • 文章类型: Journal Article
    目的:牙槽骨质量对颌面部的完整性和功能至关重要,取决于牙槽骨矿化。本研究旨在探讨体内牙槽骨矿化的变化,从生后大鼠矿物质沉积和晶体转变的角度。
    方法:Wistar大鼠出生后九个时间点,从第1天到第56天,设置为获取上颌牙槽骨样本。每个时间点由90只大鼠组成,45名女性和45名男性。牙槽骨的宏观形态通过微计算机断层扫描重新进行,矿物质含量通过热重分析进行定量。扫描电子显微镜,高分辨率透射电子显微镜和振动光谱学。此外,通过振动光谱表征结晶度和组成,X射线衍射,X射线光电子能谱和选定区域电子衍射。
    结果:在出生后的大鼠中,矿物质沉积的逐渐增加伴随着牙槽骨质量和体积的大量增长。而矿物百分比最初下降,然后上升,在出生后第14天(P14)首次观察到牙齿萌出时达到最低点。此外,局部矿化是由无定形前体的形成引发的,然后转化为矿物晶体,而生长过程中骨骼的平均结晶度没有统计学上的显着变化。
    结论:在出生后大鼠的早期生长过程中,牙槽骨的矿化是持续的。矿物沉积随年龄增加,而结晶度在一定范围内保持稳定。此外,矿物质百分比在P14达到最低点,这可能归因于牙齿萌出。
    OBJECTIVE: Alveolar bone quality is essential for the maxillofacial integrity and function, and depends on alveolar bone mineralization. This study aims to investigate the in vivo changes in alveolar bone mineralization, from the perspective of mineral deposition and crystal transition in postnatal rats.
    METHODS: Nine postnatal time points of Wistar rats, ranging from day 1 to 56, were set to obtain the maxillary alveolar bone samples. Each time point consisted of ninety rats, with 45 females and 45 males. Macromorphology of alveolar bone was reconducted by Micro-Computed Tomography and the mineral content was quantified via Thermogravimetric analysis, Scanning Electron Microscope, High-Resolution Transmission Electron Microscopy and vibrational spectroscopy. Furthermore, the crystallinity and composition were characterized by vibrational spectroscopy, X-ray Diffraction, X-ray Photoelectron Spectroscopy and Selected Area Electron Diffraction.
    RESULTS: The progressive increase of mineral deposition was accompanied by substantial growth in alveolar bone mass and volume in postnatal rats. Whereas the mineral percentage initially decreased and then increased, reaching a nadir on postnatal day 14 (P14) when tooth eruption was first observed. Besides, localized mineralization was initiated by the formation of amorphous precursors and then converted into mineral crystals, while there was no statistically significant change in the average crystallinity of the bone during growth.
    CONCLUSIONS: Mineralization of alveolar bone is ongoing throughout the early growth in postnatal rats. Mineral deposition increases with age, whereas the crystallinity remains stable within a certain range. Besides, the mineral percentage reaches its lowest point on P14, which may be attributed to tooth eruption.
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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
    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
    合成了一种新型的Fe2Mo3O8/MoO2@MoS2纳米复合材料,用于在室温下极其灵敏地检测肾脏疾病患者呼吸中的NH3。与MoS2,α-Fe2O3/MoS2和MoO2@MoS2相比,通过在900°C下优化Fe2Mo3O8的形成,显示出最佳的气敏性能。退火的Fe2Mo3O8/MoO2@MoS2纳米复合材料(Fe2Mo3O8/MoO2@MoS2-900°C)传感器显示出非常高的NH3选择性,对30ppmNH3的响应为875%,检测限为3.7ppb的超低。该传感器具有出色的线性度,重复性,和长期稳定。此外,它通过定量的NH3测量有效区分不同阶段的肾脏疾病患者。通过分析X射线光电子能谱(XPS)信号的变化来阐明传感机制,这得到了密度泛函理论(DFT)计算的支持,该计算说明了NH3吸附和氧化途径及其对电荷转移的影响,导致电导率变化作为传感信号。优异的性能主要归因于MoS2,MoO2和Fe2Mo3O8之间的异质结以及Fe2Mo3O8/MoO2@MoS2-900°C对NH3的出色吸附和催化活性。这项研究提出了一种有前途的新材料,用于检测呼出气中的NH3,并为肾脏疾病的早期诊断和管理提供了新的策略。
    A novel Fe2Mo3O8/MoO2@MoS2 nanocomposite is synthesized for extremely sensitive detection of NH3 in the breath of kidney disease patients at room temperature. Compared to MoS2, α-Fe2O3/MoS2, and MoO2@MoS2, it shows the optimal gas-sensing performance by optimizing the formation of Fe2Mo3O8 at 900 °C. The annealed Fe2Mo3O8/MoO2@MoS2 nanocomposite (Fe2Mo3O8/MoO2@MoS2-900 °C) sensor demonstrates a remarkably high selectivity of NH3 with a response of 875% to 30 ppm NH3 and an ultralow detection limit of 3.7 ppb. This sensor demonstrates excellent linearity, repeatability, and long-term stability. Furthermore, it effectively differentiates between patients at varying stages of kidney disease through quantitative NH3 measurements. The sensing mechanism is elucidated through the analysis of alterations in X-ray photoelectron spectroscopy (XPS) signals, which is supported by density functional theory (DFT) calculations illustrating the NH3 adsorption and oxidation pathways and their effects on charge transfer, resulting in the conductivity change as the sensing signal. The excellent performance is mainly attributed to the heterojunction among MoS2, MoO2, and Fe2Mo3O8 and the exceptional adsorption and catalytic activity of Fe2Mo3O8/MoO2@MoS2-900 °C for NH3. This research presents a promising new material optimized for detecting NH3 in exhaled breath and a new strategy for the early diagnosis and management of kidney disease.
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  • 文章类型: Journal Article
    砷(As)在水环境中的污染已引起广泛关注,铁化合物可能在很大程度上改变As的迁移能力。然而,在有机质(OM)的干预下,Fe-As体系中As(III)的稳定性尚不清楚。在这里,在这项研究中,我们通过使用分批实验结合傅立叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)探索了As-Fe体系的共沉淀和共氧化过程。当As/Fe比降低时,As(III)的析出量增加(28.85-92.41%),并且随着pH的增加而增加(24.20-64.20%)。氧化As(III)的主要活性物质是H2O2,它是在As-Fe系统中产生的。FTIR和XPS表明As(III)首先在中性然后吸收并进入Fe(OH)3胶体内部。但在碱性条件下,As(III)首先被Fe(Oxyhydr)氧化物吸附,然后被氧化。OM的干预会抑制As(III)在水性环境中的再分配过程。碳链的官能团和不饱和度是影响As(III)沉淀和氧化过程的主要因素,分别。共存离子(尤其是PO43-)也显著影响了系统中As(Ⅲ)的析出量,当与OM共存时,可能会加剧这一过程。共存离子对含/不含OM的As-Fe体系中As(III)的再分配过程的影响如下:PO43->SO42->混合离子>SiO32-。此外,高浓度的OM和PO43-可能导致As的形态改变,对水性环境构成威胁。总之,本研究结果旨在进一步了解和理解As在水环境中的毒性变化。特别是,OM和As的共存可能会增加饮用水安全的风险。
    The contamination of arsenic (As) in aqueous environments has drawn widespread attention, and iron compounds may largely alter the migration ability of As. However, the stability of As(III) in Fe-As system with the intervention of organic matter (OM) remains unclear. Herein, we had explored the co-precipitation and co-oxidation processes of As-Fe system by using batch experiments combined with Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) in this research. The precipitation quantity of As(III) increased (28.85-92.41 %) when the As/Fe ratio decreased, and increased (24.20-64.20 %) with pH increased. The main active substance for oxidizing As(III) was H2O2, which was produced in the As-Fe system. FTIR and XPS revealed that As(III) was first oxidized in neutral, and then absorbed and enteredthe interior of Fe(OH)3 colloids. But under alkaline conditions, As(III) was adsorbed by Fe (Oxyhydr) oxides firstly, and then oxidized. The intervention of OM would inhibit the redistribution process of As(III) in aqueous environments. Functional groups and unsaturation of the carbon chain were the dominant factors that affected the precipitation and oxidation processes of As(III), respectively. Co-existing ions (especially PO43-) also signally affected the precipitation quantity of As(Ⅲ) in the system and, when coexisting with OM, could exacerbate this process. The influence of co-existing ions on the redistributive process of As(III) in the As-Fe system with/without OM were as follows: PO43- > SO42- > mixed ions > SiO32-. Moreover, high concentration of OM and PO43- might lead to morphological alterations of As, acting as a threat to aqueous environments. In summary, the present findings were to further understand and appreciate the changes of As toxicity in the aqueous environments. Particularly, the coexistence of OM and As can potentially increase the risk to drinking water safety.
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  • 文章类型: Journal Article
    水体砷污染控制技术对保证农产品的环境卫生和质量安全具有重要意义。因此,三种吸附剂对壳聚糖的吸附性能,海泡石,在砷酸盐污染水中研究了沸石咪唑酯骨架8(ZIF-8)。结果表明,ZIF-8的吸附能力高于壳聚糖和海泡石。吸附等温线模型分析表明ZIF-8的行为与Langmuir模型较为一致。此外,利用傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)研究了3种吸附剂对砷酸盐的吸附机理。FTIR分析表明,ZIF-8通过形成As-O化学键保持了与砷酸盐相互作用的稳定性。然而,壳聚糖和海泡石对砷酸盐的吸附作用主要是物理吸附。XPS分析表明,砷酸盐对ZIF-8的吸收通过特征峰和结合能的变化涉及金属位点和氮。此外,研究了微塑料作为水中广泛共存的污染物对吸附剂性能的影响。结果表明,ZIF-8的吸附能力几乎不受微塑料的影响。砷酸盐的最大吸附量由73.45mg/g变为81.89mg/g。然而,壳聚糖和海泡石的最大吸附量分别下降了31.4%和11.6%,分别。FTIR和XPS的分析表明,ZIF-8通过在微塑料存在下形成N-O-As键来增强砷酸盐的吸附。本研究为水体中砷酸盐污染的治理提供了科学依据,特别是在含有微塑料的复杂水体中。
    Arsenic pollution control technology in water was important to ensure environmental health and quality safety of agricultural products. Therefore, the adsorption performance of three adsorbents for chitosan, sepiolite, and Zeolitic Imidazolate Framework-8 (ZIF-8) were investigated in arsenate contaminated water. The results revealed that the adsorption capacity of ZIF-8 was higher than that of chitosan and sepiolite. The analysis of adsorption isotherm models showed that the behavior of ZIF-8 was more consistent with the Langmuir model. Furthermore, the adsorption mechanisms of three adsorbents for arsenate were investigated by Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The analysis of FTIR showed that ZIF-8 maintained the stability of the interaction with arsenate by forming As-O chemical bonds. However, the effect of chitosan and sepiolite with arsenate was mainly physical adsorption. The analysis of XPS showed that the absorption of ZIF-8 with arsenate involved metal sites and nitrogen through the characteristic peak and the change of the binding energy. Furthermore, the impact of microplastics as a widespread coexistence pollutant in the water on adsorbent performance was investigated. The results indicated that the adsorption capacity of ZIF-8 was almost not affected by microplastics. The maximum adsorption amount of arsenate was changed from 73.45 mg/g to 81.89 mg/g. However, the maximum adsorption amount of chitosan and sepiolite decreased by 31.4 % and 11.6 %, respectively. The analysis of FTIR and XPS revealed that ZIF-8 enhances arsenate adsorption by forming N-O-As bonds in the presence of microplastics. This study provides scientific evidence for the management of arsenate pollution in water bodies, especially in complex water bodies containing microplastics.
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  • 文章类型: Journal Article
    内源性CO是人体内信号转导和治疗作用的重要信使。荧光成像似乎是一种有前途的内源性CO识别方法,但是传统的基于Pd配合物的发光探针存在成本高的缺陷。在这项工作中,合成了四种具有=N-N=基团的蒽衍生染料,用于Cu2辅助的CO传感。它们的分子结构,详细分析了光物理性能和对Cu2+和CO的光谱响应。该探针对Cu2+具有良好的选择性和猝灭作用,PLQY(光致发光量子产率)从0.33下降到0.04。通过与Cu2(化学计量比=1:1)形成非荧光络合物,发现猝灭机理为静态猝灭机理,正如单晶所揭示的,EPR(电子顺磁共振),和XPS(X射线光电子能谱)分析。这种淬火效应可以被CO逆转,显示恢复的荧光,PLQY在328s内恢复到0.32。还包括对细胞内源性CO成像的讨论。
    Endogenous CO acts as an important messenger for signal transduction and therapeutic effect in the human body. Fluorescent imaging appears to be a promising method for endogenous CO recognition, but traditional luminescent probes based on Pd-complexes suffered from defects of high cost. In this work, four anthracene-derived dyes having an = N-N = group were synthesized for Cu2+-assisted CO sensing. Their molecular structure, photophysical performance and spectral response to Cu2+ and CO were analyzed in detail. The optimal probe showed good selectivity and quenching effect to Cu2+, with PLQY (photoluminescence quantum yield) decreased from 0.33 to 0.04. The quenching mechanism was found as a static quenching mechanism by forming a non-fluorescent complex with Cu2+ (stoichiometric ratio = 1:1), as revealed by single crystal, EPR (electron paramagnetic resonance), and XPS (X-ray photoelectron spectroscopy) analysis. Such quenching effect could be reversed by CO, showing recovered fluorescence, with PLQY recovered to 0.32 within 328 s. Discussion on cellular endogenous CO imaging was included as well.
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