visible light

可见光
  • 文章类型: Journal Article
    通过热缩聚和共沉淀法制备了FeOOH/g-C3N4复合光催化剂,其次是XRD,SEM和UV-vis表征。通过回收试验探索了FeOOH/g-C3N4的稳定性。通过捕获实验研究了反应体系中的活性物种。结果表明,g-C3N4的最佳制备条件是在600°C下煅烧4h。XRD分析表明,g-C3N4具有高纯度相,FeOOH/g-C3N4中的Fe以高度分散的非晶态存在。SEM分析表明,FeOOH/g-C3N4具有粗糙的表面,具有不规则的层状结构。元素组成分析证实制备的催化剂中元素含量与理论计算相符。FeOOH/g-C3N4具有143.2m2/g的最大比表面积和合适的孔分布。UV-visDRS分析表明,FeOOH/g-C3N4的吸收强度强于g-C3N4。当催化剂用量为1.0g/L时,H2O2用量为4mmol/L,PNP初始浓度为10mg/L,初始pH值为5时,PNP去除率在120min内可达到92%。即使经过5个周期,FeOOH/g-C3N4对PNP的去除效率保持近80%。捕获实验表明,·OH和·O2-都在PNP的光催化降解中起作用,·OH更重要。这些发现证实了FeOOH已成功掺入g-C3N4中,从而在可见光辅助的类Fenton反应中对PNP的降解产生了显着的催化作用。
    The composite photocatalyst FeOOH/g-C3N4 was prepared through thermal polycondensation and co-precipitation methods, followed by XRD, SEM and UV-vis characterization. The stability of FeOOH/g-C3N4 was explored by the recycling test. The active species in the reaction system were investigated by the capture experiment. The results indicated that the optimal preparation condition for g-C3N4 involved calcination at 600 °C for 4 h. XRD analysis revealed that g-C3N4 exhibits a high-purity phase, and Fe in FeOOH/g-C3N4 exists in a highly dispersed amorphous state. SEM analysis showed that FeOOH/g-C3N4 has a rough surface with an irregular layered structure. Element composition analysis confirmed that the content of elements in the prepared catalyst is consistent with the theoretical calculation. FeOOH/g-C3N4 possesses the largest specific surface area of 143.2 m2/g and a suitable pore distribution. UV-vis DRS analysis showed that the absorption intensity of FeOOH/g-C3N4 is stronger than that of g-C3N4. When the catalyst dosage was 1.0 g/L, the H2O2 dosage was 4 mmol/L, the PNP initial concentration was 10 mg/L and the initial pH value was 5, the PNP removal could reach 92% in 120 min. Even after 5 cycles, the efficiency of PNP removal by FeOOH/g-C3N4 remains nearly 80%. The capture experiment indicated that both •OH and •O2- play roles in the photocatalytic degradation of PNP, with •OH being more significant. These findings affirm that FeOOH has been successfully incorporated into g-C3N4, resulting in a conspicuous catalytic effect on the degradation of PNP in the visible light-assisted Fenton-like reaction.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    水污染是一项重大的环境挑战。由于常规污水处理厂降解许多有机复杂化合物的效率低下,这些顽固的污染物最终进入河流,湖泊,海洋和其他水体,影响环境和人类健康。半导体光催化被认为是传统方法的有效补充,并为此目的广泛探索了各种纳米材料的使用,特别注重改善他们在可见光下的活动。这项工作的重点是通过溶胶-凝胶和溶剂热合成方法开发磁性和光敏锌/镁混合铁氧体(Zn0.5Mg0.5Fe2O4),这是用于合成铁氧体纳米颗粒的两种最重要和最有效的方法。通过溶胶-凝胶法合成的纳米颗粒(NP)的平均尺寸为14.7nm,而溶剂热法合成的平均粒径为17.4nm。这两种类型都具有主要的立方结构,并表现出超顺磁性行为,达到60.2emug-1的磁化强度饱和值。由于电子/空穴的高复合率,这是铁氧体的固有特征,用银进行表面官能化以增强电荷分离。结果证明了银的吸附和沉积的强烈影响。在合成过程中进行了几个优化步骤,让我们创造出高效的催化剂,通过使用溶胶-凝胶和溶剂热法获得的NP,几乎完全去除染料孔雀石绿,达到95.0%(在0.091min-1的速率常数下)和87.6%(在0.017min-1的速率常数下),分别。对于通过溶胶-凝胶制备的纳米颗粒,黑暗中的吸附占染料去除率的89.2%,对于通过溶剂热法获得的纳米颗粒,则占染料去除率的82.8%。这些结果使得混合锌/镁铁氧体在使用可见光的废水光修复中的潜在工业应用非常有前途。
    Water pollution is a major environmental challenge. Due to the inefficiency of conventional wastewater treatment plants in degrading many organic complex compounds, these recalcitrant pollutants end up in rivers, lakes, oceans and other bodies of water, affecting the environment and human health. Semiconductor photocatalysis is considered an efficient complement to conventional methods, and the use of various nanomaterials for this purpose has been widely explored, with a particular focus on improving their activity under visible light. This work focuses on developing magnetic and photoactive zinc/magnesium mixed ferrites (Zn0.5Mg0.5Fe2O4) by sol-gel and solvothermal synthesis methods, which are two of the most important and efficient methods used for the synthesis of ferrite nanoparticles. The nanoparticles (NPs) synthesized by the sol-gel method exhibited an average size of 14.7 nm, while those synthesized by the solvothermal method had an average size of 17.4 nm. Both types possessed a predominantly cubic structure and demonstrated superparamagnetic behavior, reaching a magnetization saturation value of 60.2 emu g-1. Due to the high recombination rate of electrons/holes, which is an intrinsic feature of ferrites, surface functionalization with silver was carried out to enhance charge separation. The results demonstrated a strong influence of adsorption and of the deposition of silver. Several optimization steps were performed during synthesis, allowing us to create efficient catalysts, as proved by the almost full removal of the dye malachite green attaining 95.0% (at a rate constant of 0.091 min-1) and 87.6% (at a rate constant of 0.017 min-1) using NPs obtained by the sol-gel and solvothermal methods, respectively. Adsorption in the dark accounted for 89.2% of the dye removal for nanoparticles prepared by sol-gel and 82.8% for the ones obtained by the solvothermal method. These results make mixed zinc/magnesium ferrites highly promising for potential industrial application in effluent photoremediation using visible light.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    在室温下操作的NO2传感器的不良恢复特性的持续挑战仍然是显著的。然而,基于In2O3的气敏材料的开发提供了一种有希望的方法来加速室温下NO2亚ppm检测的响应和恢复。在这里,我们提出了一种简单的两步法来合成具有中空微管的一维(1D)In2O3@ZnO异质结构材料,通过偶联金属-有机骨架(MOFs)(MIL-68(In))和锌离子。同时,基于In2O3@ZnO复合材料的气体传感器在可见光激活下对NO2表现出优异的灵敏度性能。室温下对5ppmNO2的响应值高达1800,是纯In2O3基传感器的35倍。此外,与基于纯In2O3的传感器(74s/235s)相比,基于In2O3@ZnO异质结构的气体传感器显着减少了30s/67s的响应/恢复时间。In2O3@ZnO异质结构传感器的出色气敏特性可归因于异质结构效应导致的光生电荷分离效率提高,并改善了对NO2的受体功能,这可以增加反应位点和气体吸附能力。总之,这项工作提出了一种低成本,高效的方法来合成具有微管结构的一维异质结构材料,它可以作为开发高性能室温气体传感器的基本技术。
    The persistent challenge of poor recovery characteristics of NO2 sensors operated at room temperature remains significant. However, the development of In2O3-based gas sensing materials provides a promising approach to accelerate response and recovery for sub-ppm of NO2 detection at room temperature. Herein, we propose a simple two-step method to synthesize a one-dimensional (1D) In2O3@ZnO heterostructure material with hollow microtubes, by coupling metal-organic frameworks (MOFs) (MIL-68 (In)) and zinc ions. Meanwhile, the In2O3@ZnO composite-based gas sensor exhibits superior sensitivity performance to NO2 under visible light activation. The response value to 5 ppm of NO2 at room temperature is as high as 1800, which is 35 times higher than that of the pure In2O3-based sensor. Additionally, the gas sensor based on the In2O3@ZnO heterostructure demonstrates a significantly reduced response/recovery time of 30 s/67 s compared to the sensor based on pure In2O3 (74 s/235 s). The outstanding gas sensing properties of the In2O3@ZnO heterostructure-based sensors can be attributed to the enhanced photogenerated charge separation efficiency resulting from the heterostructure effect, and the improved receptor function toward NO2, which can increase the reactive sites and gas adsorption capacity. In summary, this work proposes a low-cost and efficient method to synthesize a 1D heterostructure material with microtube structures, which can serve as a fundamental technique for developing high-performance room-temperature gas sensors.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    背景:先前的研究表明,光线可能与隐形眼镜相互作用,可能会影响其透射率。
    目的:本研究旨在研究可见光和紫外线(UV)-A光源对一些市售日常透光率的影响,每周,和每月隐形眼镜。
    方法:用太阳模拟器照射九种市售软性隐形眼镜,发光二极管(LED)源,激光源,和UV-A源。受测镜片在紫外线照射前后的平均透射率,可见,使用安捷伦紫外可见分光光度计确定红外光的波长范围,模型8453。
    结果:结果显示,Bio真正的日常隐形眼镜在UV-B区域(300nm)和UV-A区域(355nm)处的UV透射部分或完全阻断,以及AcuvueOasys,Avaira,和生物55每周镜片。在可见光区(555nm),不同光源照射隐形眼镜导致透光率降低。在红外区域(900nm),每周和每月的隐形眼镜部分阻挡了红外透射,而日常镜片显示红外透射率增加或减少。
    结论:太阳能和人工照明,以及高功率激光器,构成对隐形眼镜的光透射和光学特性的主要关注。开发具有光防护性能同时保持可见光透射率的软接触透镜是必要的。
    BACKGROUND: Previous studies have suggested that light rays may interact with contact lenses, potentially affecting their transmittance.
    OBJECTIVE: This study aimed to investigate the effects of visible and ultraviolet (UV)-A light sources on the transmittance of some commercially available daily, weekly, and monthly contact lenses.
    METHODS: Nine commercially available soft contact lenses were irradiated with a solar simulator, light-emitting diode (LED) source, laser source, and UV-A source. The average transmittance of the tested lenses before and after irradiation in the UV, visible, and infrared light wavelength ranges was determined using an Agilent UV-visible spectrophotometer, model 8453.
    RESULTS: The results showed a partial or complete block of UV transmission at the UV-B region (300 nm) and the UV-A region (355 nm) by the Bio true daily contact lens, as well as the Acuvue Oasys, Avaira, and Biomedics 55 weekly lenses. At the visible region (555 nm), irradiation of the contact lenses by different light sources resulted in reduced light transmittance. At the infrared region (900 nm), the weekly and monthly contact lenses partially blocked infrared transmission, while the daily lenses showed either increased or decreased infrared transmission.
    CONCLUSIONS: Solar and artificial lighting, as well as high-powered lasers, constitute a major concern on the contact lenses\' light transmission and optical properties. It is essential to develop soft contact lenses that have photoprotective properties while maintaining visible light transmittance.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    C─H杂芳烃的官能化是有机合成中的有效工具,随着可见光的结合,它成为一个变革性的游戏规则改变者。在这个领域,电子供体-受体(EDA)复合物,通过富电子底物与电子接受分子的配对形成,近年来,由于避免了对光催化剂和氧化剂的需求,因此引起了广泛的考虑。EDA复合物可以在温和条件下进行光活化,并表现出高的官能团耐受性,使它们潜在地适合于生物相关的异芳烃的功能化。这篇综述文章概述了通过EDA络合物光活化对杂芳烃进行C-H官能化领域的最新进展,文献报道截至4月,2024.
    C─H Functionalization of heteroarenes stands as a potent instrument in organic synthesis, and with the incorporation of visible light, it emerged as a transformative game-changer. In this domain, electron donor-acceptor (EDA) complex, formed through the pairing of an electron-rich substrate with an electron-accepting molecule, has garnered substantial consideration in recent years due to the related avoidance of the requirement of photocatalyst as well as oxidant. EDA complexes can undergo photoactivation under mild conditions and exhibit high functional group tolerance, making them potentially suitable for the functionalization of biologically relevant heteroarenes. This review article provides an overview of recent advancements in the field of C─H functionalization of heteroarenes via EDA complex photoactivation with literature coverage up to April, 2024.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    在这项研究中,我们研究了使用铂化氧化钨(Pt/WO3)对阻燃剂四溴双酚A(TBBPA)的降解,通过简单的光沉积方法合成,在可见光下。降解实验的结果表明,在WO3的表面铂化后,TBBPA的降解显着增强,与裸露的WO3相比,降解速率提高了13.4倍。WO3表面上Pt的存在存储导带电子,这促进了氧的双电子还原,并增强了价带空穴(hVB)和羟基自由基(●OH)的产生。在可见光照射的Pt/WO3系统中,hVB和●OH均显着参与TBBPA的降解。通过使用香豆素作为化学探针的荧光光谱法和氧化物种猝灭实验来验证这一点。降解产物的分析及其毒性评估表明,在Pt/WO3光催化作用后,TBBPA污染的水的毒性显着降低。TBBPA的降解率随着Pt/WO3用量的增加而增加,在Pt含量为0.5wt%时达到最佳状态,但随着TBBPA浓度的增加而降低。Pt/WO3的降解效率下降很小,在各种阴离子的存在和重复使用后。本研讨提出Pt/WO3是可见光下降解水中TBBPA的可行光催化剂。
    In this study, we investigated the degradation of the flame retardant tetrabromobisphenol A (TBBPA) using platinized tungsten oxide (Pt/WO3), synthesized via a simple photodeposition method, under visible light. The results of degradation experiments show a significant enhancement in TBBPA degradation upon surface platinization of WO3, with the degradation rate increasing by 13.4 times compared to bare WO3. The presence of Pt on the WO3 surface stores conduction band electrons, which facilitates the two-electron reduction of oxygen and enhances the production of valence band holes (hVB+) and hydroxyl radicals (●OH). Both hVB+ and ●OH are significantly involved in the degradation of TBBPA in the visible light-irradiated Pt/WO3 system. This was verified through fluorescence spectroscopy employing coumarin as a chemical probe and oxidizing species-quenching experiments. The analysis of degradation products and their toxicity assessment demonstrate that the toxicity of TBBPA-contaminated water is significantly reduced after Pt/WO3 photocatalysis. The degradation rate of TBBPA increased with increasing Pt/WO3 dosage, reached an optimum at a Pt content of 0.5 wt%, but decreased with increasing TBBPA concentration. The decrease in degradation efficiency of Pt/WO3 was minor, both in the presence of various anions and after repeated use. This study proposes that Pt/WO3 is a viable photocatalyst for the degradation of TBBPA in water under visible light.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    可见光介导的反应最近已成为在温和反应条件下合成多种有机分子的有力策略。通常,反应在室温下进行,因此敏感官能团保持不受影响。因此,该协议受到了学术界和工业界的强烈兴趣。杂环,总的来说,由于它们的生物活性和在治疗中的应用而引起了极大的兴趣。含氧和含硫杂环化合物最近引起了人们的关注,因为这些化合物显示出作为抗癌药物的有希望的活性,抗生素,抗真菌和抗炎药在其他应用。通过有效和更绿色的途径合成这类化合物已成为重要的目标。这篇综述强调了在可见光诱导的反应下合成这些化合物及其衍生物的各种程序。讨论了每个程序的绿色方面和机制。
    Visible-light-mediated reactions have recently emerged as a powerful strategy for the synthesis of diverse organic molecules under mild reaction conditions. Usually, the reactions are performed at room temperature and thus sensitive functional groups remain unaffected. Thus, this protocol has received intense interest from academia as well as industries. The heterocycles, in general, are of much interest because of their biological activities and application in therapeutics. The Oxygen- and Sulfur-containing heterocyclic compounds have recently attracted attention as these compounds showed promising activities as anti-cancer drugs, antibiotics, antifungal and anti-inflammatory agents among other applications. The synthesis of this class of compounds by efficient and greener routes has become an important target. This review highlights the various procedures for the synthesis of these compounds and their derivatives under visible light-induced reactions. The green aspects and mechanism of each procedure have been discussed.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    激发光活性电子供体-受体(EDA)络合物以产生自由基是自由基化学中的一种有前途的方法。在这项研究中,我们介绍了一种新的H键EDA配合物模型,用于在可见光条件下羰基活化的烯烃与多种硫醇的选择性氢硫醇化和羟基亚磺酰化。这种H键EDA复杂模型的可靠性已通过细致的实验和理论计算得到证实。机理研究表明,溶剂在确定光敏H键EDA复合物的激发是否会导致电荷转移(CT)或能量-电荷转移(En-CT)方面具有重大影响,从而控制Markovnikov和反Markovnikov选择性。值得注意的是,分子中原子的量子理论(QTAIM)分析清楚地表明,C=O---H-SEDA复合物的激发态涉及闭壳部分共价相互作用。
    Excitation of photoactive electron donor-acceptor (EDA) complexes to generate radical is a promising approach in radical chemistry. In this study, we introduce a new model of H-bonding EDA complexes for the selective hydrothiolation and hydroxysulfenylation of carbonyl-activated alkenes with diverse thiols under visible light conditions. The reliability of this H-bonding EDA complex model has been confirmed by meticulous experimental and theoretical calculations. Mechanistic investigations have revealed the significant influence of the solvent in determining whether the excitation of photoactive H-bonding EDA complex leads to charge transfer (CT) or energy-charge transfer (En-CT), thereby controlling Markovnikov and anti-Markovnikov selectivity. Notably, the Quantum Theory of Atoms in Molecules (QTAIM) analysis clearly shows that the excited state of the C=O---H-S EDA complex involves closed-shell partially covalent interactions.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    通过光控可逆失活自由基聚合(photoRDRP)技术的光诱导3D打印已经成为一种用于制造聚合物材料的强大技术。然而,精确调整这些材料的机械性能的方法仍然有限。在这项研究中,我们提出了一种简单的方法,通过在基于NorrishI型光引发可逆加成-断裂链转移(NTI-RAFT)聚合的3D打印过程中调节聚合物分散性来调节3D打印物体的机械性能。我们研究了改变三硫代碳酸酯(BTPA)和黄原酸酯(EXEP)的浓度和摩尔比对印刷材料机械性能的影响。我们的研究结果表明,增加RAFT剂的浓度或更高比例的更活性的BTPA导致杨氏模量和玻璃化转变温度的降低,随着断裂伸长率的增加,这可以归因于聚合物网络的均匀性增强。使用商用液晶打印机,基于NTI-RAFT的3D打印系统有效地生产了具有定制机械性能的材料,突出其实际应用的潜力。
    Photoinduced 3D printing via photocontrolled reversible-deactivation radical polymerization (photoRDRP) techniques has emerged as a robust technique for creating polymeric materials. However, methods for precisely adjusting the mechanical properties of these materials remain limited. In this study, we present a facile approach for adjusting the mechanical properties of 3D-printed objects by adjusting the polymer dispersity within a Norrish type I photoinitiated reversible addition-fragmentation chain transfer (NTI-RAFT) polymerization-based 3D printing process. We investigated the effects of varying the concentrations and molar ratios of trithiocarbonate (BTPA) and xanthate (EXEP) on the mechanical properties of the printed materials. Our findings demonstrate that increased concentrations of RAFT agents or higher proportions of the more active BTPA lead to a decrease in Young\'s modulus and glass transition temperatures, along with an increase in elongation at break, which can be attributed to the enhanced homogeneity of the polymer network. Using a commercial LCD printer, the NTI-RAFT-based 3D printing system effectively produced materials with tailored mechanical properties, highlighting its potential for practical applications.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    大多数单克隆抗体制剂需要表面活性剂的存在,如聚山梨酯,确保蛋白质的稳定性。高浓度聚山梨酯的存在已显示出增强某些蛋白质药物产品在暴露于可见光时的光氧化。当前的文学,然而,建议聚山梨酯的光氧化仅在暴露于可见光与UVA光结合时才发生。这很可能是因为聚山梨酯溶液中存在的过氧化物可以在UVA区域中均匀裂解。在可见区域,预计不会发生光氧化,因为在这些波长下不会发生过氧化物的裂解。该报告提出的发现表明聚山梨酯中一种或多种光敏剂的存在必须是在暴露于可见光时催化聚山梨酯溶液的需氧氧化的原因和要求。我们的研究旨在阐明聚山梨酯光氧化的机制,并探索生成的自由基的动力学和身份及其对单克隆抗体(mAb)降解的影响。我们的研究表明,当聚山梨酯溶液在没有蛋白质的情况下暴露于400---800nm之间的可见光时,变色,自由基形成,和氧气消耗发生。我们讨论了反应性物种的初始形成,很可能直接发生在分子氧反应之后,三重态光敏剂的存在,它是由激发单重态的系统间交叉产生的,主要导致形成反应性物种,如单线态氧物种。当比较不同质量等级的PS20和PS80的光氧化时,我们认为单线态氧具有与PS80HP中的不饱和脂肪酸反应的潜力,然而,PS20HP本身在测试条件下没有表现出可测量的氧化。本研究的最后一部分深入研究了不同PS等级的光氧化行为,检查其对制剂中mAb完整性的影响。最后,我们研究了光氧化对单克隆抗体完整性的影响.我们的研究结果表明,在含有聚山梨酯的mAb溶液中,在4mg·ml-1的高PS浓度下暴露于可见光会导致单克隆抗体降解增加,强调需要谨慎评估正确的PS浓度以稳定蛋白质疗法。
    Most monoclonal antibody formulations require the presence of a surfactant, such as polysorbate, to ensure protein stability. The presence of high concentrations of polysorbate have been shown to enhance photooxidation of certain protein drug products when exposed to visible light. The current literature, however, suggest that photooxidation of polysorbate only occurs when exposed to visible light in combination with UVA light. This is probable as peroxides present in polysorbate solutions can be cleaved homolytically in the UVA region. In the visible region, photooxidation is not expected to occur as cleavage of peroxides is not expected at these wavelengths. This report presents findings suggesting that the presence of one or more photosensitiser(s) in polysorbate must be a cause and is required to catalyse the aerobic oxidation of polysorbate solutions upon exposure to visible light. Our investigation aimed to clarify the mechanism(s) of polysorbate photooxidation and explore the kinetics and the identity of the generated radicals and their impact on monoclonal antibody (mAb) degradation. Our study reveals that when polysorbate solutions are exposed to visible light between 400---800 nm in the absence of proteins, discoloration, radical formation, and oxygen depletion occur. We discuss the initial formation of reactive species, most likely occurring directly after reaction of molecular oxygen, with the presence of a triplet state photosensitizer, which is generated by intersystem crossing of the excited singlet state, leading predominantly to the formation of reactive species such as singlet oxygen species. When comparing the photooxidation of PS20 and PS80 in varying quality grades, we propose that singlet oxygen possesses potential for reacting with unsaturated fatty acids in PS80HP, however, PS20HP itself exhibited no measurable oxidation under the tested conditions. The study\'s final part delves into the photooxidation behaviour of different PS grades, examining its influence on the integrity of a mAb in the formulation. Finally, we examined the effect of photooxidation on the integrity of monoclonal antibodies. Our findings show that the exposure to visible light in polysorbate-containing mAb solutions at high PS concentrations of 4 mg∙ml-1 results in increased monoclonal antibody degradation, highlighting the need for cautious evaluation of the correct PS concentration to stabilise protein therapeutics.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号