Photo-degradation

光降解
  • 文章类型: Journal Article
    在这项研究中,通过简单的煅烧和水热技术,开发了一种具有Z方案光催化剂的高效CoFe2O4锚定g-C3N4纳米复合材料。为了评估晶体结构,样品表面形貌,元素成分,通过各种表征技术对合成催化剂的电荷电导率和电荷电导率。CoFe2O4纳米颗粒(NPs)与g-C3N4纳米片的高界面接触将光学带隙从2.67降低到2.5eV,提高了载流子的分离和转移。以亚甲基蓝(MB)和罗丹明B(RhB)水性污染物悬浮液在可见光影响下的光降解为研究有效的CoFe2O4/g-C3N4复合催化剂的光催化降解活性。具有Z方案的异质结构尖晶石CoFe2O4锚定g-C3N4光催化剂(PC)对两种有机染料均显示出更好的光催化降解性能。同时,在可见光下120分钟和100分钟内,水性MB和RhB的降解效率可达91.1%和73.7%,其大于原始g-C3N4和CoFe2O4催化剂。循环稳定性测试显示在四个重复循环后光降解活性没有显著变化。因此,这项工作为构建高效磁性PC以去除水生环境中的有害污染物提供了有效的策略。
    In this study, a highly efficient CoFe2O4-anchored g-C3N4 nanocomposite with Z-scheme photocatalyst was developed by facile calcination and hydrothermal technique. To evaluate the crystalline structure, sample surface morphology, elemental compositions, and charge conductivity of the as-synthesized catalysts by various characterization techniques. The high interfacial contact of CoFe2O4 nanoparticles (NPs) with g-C3N4 nanosheets reduced the optical bandgap from 2.67 to 2.5 eV, which improved the charge carrier separation and transfer. The photo-degradation of methylene blue (MB) and rhodamine B (Rh B) aqueous pollutant suspension under visible-light influence was used to investigate the photocatalytic degradation activity of the efficient CoFe2O4/g-C3N4 composite catalyst. The heterostructured spinel CoFe2O4 anchored g-C3N4 photocatalysts (PCs) with Z-scheme show better photocatalytic degradation performance for both organic dyes. Meanwhile, the efficiency of aqueous MB and Rh B degradation in 120 and 100 min under visible-light could be up to 91.1% and 73.7%, which is greater than pristine g-C3N4 and CoFe2O4 catalysts. The recycling stability test showed no significant changes in the photo-degradation activity after four repeated cycles. Thus, this work provides an efficient tactic for the construction of highly efficient magnetic PCs for the removal of hazardous pollutants in the aquatic environment.
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  • 文章类型: Journal Article
    通过迷迭香叶提取物在90和200°C下制备二氧化钛(TiO2)纳米颗粒。在这项研究中,研究了使用TiO2纳米粒子太阳光辐射对亚甲基蓝的降解。使用XRD对合成的材料进行了表征,UV-Vis,PL,SEM,TEM,EDS和XPS。结果表明,生物合成温度会影响TiO2纳米颗粒的形状和尺寸。对于TiO2-90,显微照片显示可分离的晶体具有不规则的形态和团聚的立方颗粒。对于其他TiO2-200样品,SEM和TEM显微成像显示碎裂团聚的立方结构。XRD表明,在25.37°的角度观察到强烈的峰,37.19°,47.81°和53.89°确认高度结晶取向为(004),(200),和(105)平面分别。通过PL和UV-Vis传达了合成的TiO2纳米粒子的光学性质。对于两个样品计算的能带隙为3.0eV;这表明加热温度不影响样品的带隙。元素组成Ti和O2由EDS和XPS示出。光催化实验发现,TiO2-90纳米粒子在MB的光降解中组织良好,比作TiO2-200。TiO2-90的巨大活性是由于与TiO2-200相关的更好的物理化学特性在光下有效降解MB。通过更简单的技术合成的TiO2可在阳光下对染料进行光降解,作为可充分获得的能源,有希望发展一个生态友好和经济的过程。
    Titanium dioxide (TiO2) nanoparticles were prepared through Rosmarinus-officinalis leaf extracts at 90 and 200°C. In this research, the degradations of methylene blues by using TiO2 nanoparticles Sun light radiations were studied. The synthesized materials were characterized using XRDs, UV-Vis, PL, SEM, TEM, EDS and XPS. The results displayed that bio-synthesis temperatures intrude the shapes and sizes of TiO2 nanoparticles. For TiO2-90, micrographs show separable crystalline with irregular morphologies and agglomerate cubic particles. For the other TiO2-200 sample, SEM and TEM micro-imaging shows crumbly agglomerated cubic structures. The XRD shows that the intense peaks observed at angles of 25.37°, 37.19°, 47.81° and 53.89° confirming a highly crystalline oriented as (004), (200), and (105) planes respectively. The optical properties of TiO2 nanoparticles synthesized were conveyed by PL and UV-Vis. The energy band gap calculated was 3.0 eV for both samples; that indicates heating temperature didn\'t influence the band gap of the samples. The elemental composition Ti and O2 is shown by EDS and XPS. Photo-catalytic experiments discovered that TiO2-90 nanoparticles were well-organized in photo-degradations of MB, likened to TiO2-200. The great activities of TiO2-90 were because of better physicochemical characteristics associated with TiO2-200 effectively degrading MB under photo-light. Photo-degradations of dye under sunlight as plentifully obtainable energy sources by TiO2, synthesized by simpler techniques, can be hopeful to grow an eco-friendly and economical process.
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  • 文章类型: Journal Article
    在具有谐振器主体的乐器的声学中,由于木材结晶度的增加,木材的老化导致声学性能的改善。这种现象可以通过以下事实来解释:木材是基于碳水化合物的三维聚合物链的复杂产品,其老化与聚合物链的共价交联和断裂密切相关。这项研究的目的是在多尺度上评估的变化产生的人工老化的色调木材,机械和化学参数。在暴露于紫外线(UV)辐射之前和之后,对云杉和枫木样品进行了研究,通过拉伸试验,飞行时间法(TOF),通过傅里叶变换红外光谱(FTIR)和X射线衍射(XRD)对木材进行颜色分析和化学指纹图谱的测定。获得的结果表明,人工老化的影响表现在化学水平,其中结晶度增加到声学水平,取决于木材种类和它们的质量等级。这些结果与乐器制造商找到导致优异声学性能的处理相关。
    In the acoustics of musical instruments with a resonator body, the aging of the wood leads to the improvement of the acoustic properties due to increasing the crystallinity of wood. This phenomenon could be explained by the fact that wood is a complex product based on three-dimensional polymer chains of carbohydrates, its aging being closely related to covalent cross-linking and scission of polymer chains. The aim of this study was to evaluate at a multiscale the changes produced artificial aging of tone wood by measuring the acoustic, mechanical and chemical parameters. The spruce and maple wood samples were investigated before and after exposure to ultraviolet (UV) radiation, through the tensile test, the time-of-flight method (TOF), the analysis of the wood color and the determination of the chemical fingerprint through Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The obtained results showed that the effects of artificial aging are manifested at the chemical level where the crystallinity increases up to the acoustic level, depending on the wood species and their quality class. These results are relevant for musical instrument manufacturers to find treatments that lead to superior acoustic properties.
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  • 文章类型: Journal Article
    Cu(II)-有机酸(部分I)和Cu(I)-硫醇(部分II)配合物可以抑制葡萄酒中的巯基异味。本研究调查了光照对瓶装白葡萄酒中铜保护成分的影响。将具有两种初始溶解氧浓度(0.5和10mg/L)的荧光曝光霞多丽储存在不同颜色的瓶子中,并含有浓度的Cu级分和核黄素,370-440nm的光引发剂,在110天的储存过程中进行了测量。氧气浓度较低的光照葡萄酒导致Cu组分I半衰期降低100倍,合并的Cu级分I和II减少了60倍。与火石玻璃相比,使用棕色的Cu部分I在曝光过程中的衰减半衰期延长了30倍。光照可以迅速耗尽葡萄酒中的铜保护成分,和低于440nm的透光率较低的瓶子可以减缓这种损失。
    Cu(II)-organic acid (fraction I) and Cu(I)-thiol (fraction II) complexes can suppress sulfhydryl off-aromas in wine. This study investigated the impact of light exposure on the protective fractions of Cu of bottled white wine. Fluorescent light-exposed Chardonnay with two initial concentrations of dissolved oxygen (0.5 and 10 mg/L) was stored in different coloured bottles and concentrations of Cu fractions and riboflavin, a photo-initiator at 370-440 nm, were measured during 110 days storage. Light-exposed wines with lower oxygen concentrations resulted in a 100-fold decrease in the Cu fraction I half-life, and a 60-fold decrease for Cu fractions I and II combined. The half-life for Cu fraction I decay during light exposure was extended 30-fold with the use of brown compared to flint glass. Light exposure can rapidly exhaust the protective Cu fractions in wine, and bottles with less light transmission below 440 nm can slow this loss.
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  • 文章类型: Journal Article
    环境事故突出表明,需要开发可用于消除包括原油及其衍生物在内的污染物的有效材料,以及有毒的有机溶剂。近年来,已经研究了各种各样的先进材料,以协助环境受损地区的净化过程,主要参赛者是基于石墨烯的结构。这项研究描述了用两种方法合成石墨烯气凝胶,并确定了它们作为几种水污染物吸附剂的效率。两种合成路线之间的主要区别是在第一种情况下使用冷冻干燥,和环境压力干燥在后者。拉曼光谱,扫描电子显微镜(SEM),X射线衍射(XRD)X射线光电子能谱(XPS)和接触角测量在此用于样品的表征。已发现制备的气凝胶可用作染料水溶液的光催化剂,例如亚甲基蓝和橙色G,虽然它们也被评估为有机溶剂的吸附剂(丙酮,乙醇和甲醇),and,油,如泵油,蓖麻油,硅油,也是。这里提出的结果表明,冷冻干燥方法为大多数被检查的污染物提供了更好的吸附效率的材料,然而,环境压力干燥的节能和节省成本的优势可以抵消前者的吸附优势。
    Environmental accidents highlight the need for the development of efficient materials that can be employed to eliminate pollutants including crude oil and its derivatives, as well as toxic organic solvents. In recent years, a wide variety of advanced materials has been investigated to assist in the purification process of environmentally compromised regions, with the principal contestants being graphene-based structures. This study describes the synthesis of graphene aerogels with two methods and determines their efficiency as adsorbents of several water pollutants. The main difference between the two synthesis routes is the use of freeze-drying in the first case, and ambient pressure drying in the latter. Raman spectroscopy, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS) and contact angle measurements are employed here for the characterisation of the samples. The as-prepared aerogels have been found to act as photocatalysts of aqueous dye solutions like methylene blue and Orange G, while they were also evaluated as adsorbents of organic solvents (acetone, ethanol and methanol), and, oils like pump oil, castor oil, silicone oil, as well. The results presented here show that the freeze-drying approach provides materials with better adsorption efficiency for the most of the examined pollutants, however, the energy and cost-saving advantages of ambient-pressure-drying could offset the adsorption advantages of the former case.
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  • 文章类型: Journal Article
    用于化学传感和大分子修饰的纳米工具的开发是生物医学领域的新挑战。重点是设计用于在特定位点切割肽键的人工肽酶。在这个景观中,金属卟啉是有吸引力的,因为它们能够与氨基酸形成稳定的络合物,并在被适当波长的光照射时产生活性氧。卟啉在水性环境中的疏水行为和聚集问题可以通过使用其聚乙二醇化衍生物来解决。这项工作提出了一种基于聚乙二醇化汞卟啉的人工光蛋白酶剂的设计,能够与l-色氨酸形成稳定的复合物,也存在于溶菌酶结构中的氨基酸(众所周知的蛋白质模型)。利用聚乙二醇化汞卟啉的传感和光降解特性,利用ROS检测和降解l-Trp和溶菌酶,在绿色(532nm)和红色(650nm)光激光下产生。通过几种光谱学(UV-Vis,荧光和圆二色性),和MALDI-TOF质谱,显示溶菌酶的裂解和几个短链残基的出现。这项研究的方法为治疗和靶向生物医学治疗的潜在应用铺平了道路。
    The development of nanotools for chemical sensing and macromolecular modifications is a new challenge in the biomedical field, with emphasis on artificial peptidases designed to cleave peptide bonds at specific sites. In this landscape, metal porphyrins are attractive due to their ability to form stable complexes with amino acids and to generate reactive oxygen species when irradiated by light of appropriate wavelengths. The issues of hydrophobic behavior and aggregation in aqueous environments of porphyrins can be solved by using its PEGylated derivatives. This work proposes the design of an artificial photo-protease agent based on a PEGylated mercury porphyrin, able to form a stable complex with l-Tryptophan, an amino acid present also in the lysozyme structure (a well-known protein model). The sensing and photodegradation features of PEGylated mercury porphyrin were exploited to detect and degrade both l-Trp and lysozyme using ROS, generated under green (532 nm) and red (650 nm) light lasers. The obtained system (Star3600_Hg) and its behavior as a photo-protease agent were studied by means of several spectroscopies (UV-Vis, fluorescence and circular dichroism), and MALDI-TOF mass spectrometry, showing the cleavage of lysozyme and the appearance of several short-chain residues. The approach of this study paves the way for potential applications in theranostics and targeted bio-medical therapies.
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  • 文章类型: Journal Article
    大多数投放市场的片剂用可溶于水的聚合物包衣。ColorconInc.的OpadryII85系列,是自20世纪90年代以来销售的PVA基产品家族。尽管发表了许多关于PVA性质的出版物,到目前为止,已经进行了有限的工作来确定物理化学参数(即,UV光,高温,和相对湿度),这可能会影响PVA基涂料的性能。为此,我们对OpadryOrangeII或该涂层的某些选定成分制成的样品进行了人工老化过程,并通过多学科方法对其进行了分析。使用,例如,FTIR,NMR,流变学,和DMTA测量。这样,我们分析了OpadryOrangeII配方的关键成分的影响,如二氧化钛和氢氧化铝,老化条件下的涂层特性。
    Most tablets put on the market are coated with polymers soluble in water. The Opadry II 85 series from Colorcon Inc., is a family of PVA-based products marketed since the 1990s. Despite numerous publications on the properties of PVA, to date, limited work has been undertaken to determine the physico-chemical parameters (i.e., UV light, high temperature, and relative humidity) that could affect the performance of PVA-based coatings. To this end, we performed artificial ageing processes on samples made of Opadry Orange II or of some selected components of this coating and analysed them by means of a multidisciplinary approach, using, for example, FTIR, NMR, rheology, and DMTA measurements. In this way, we analysed the influence of the critical components of the Opadry Orange II formula, such as titanium dioxide and aluminium hydroxide, on the coating characteristics under ageing conditions.
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  • 文章类型: Journal Article
    溶解性有机质(DOM)在确定物种形态方面非常重要,行为,和水生生态系统中金属污染物的风险。光化学和微生物降解是DOM循环的关键过程,然而,它们对DOM-Pb(II)相互作用的影响仍然很大程度上未知。通过研究降解后河流DOM与Pb(II)的络合进行了研究,使用荧光猝灭滴定和激发-发射矩阵-平行因子分析(EEMs-PARAFAC)。确定了三种腐殖质样成分和两种蛋白质样成分,通过光和光微生物降解,强烈去除类腐殖质成分,并降低DOM的平均分子量和腐殖质程度。腐殖质丰度和结构的变化导致它们与Pb(II)的相互作用显着减弱。色氨酸样C2也主要通过光降解去除,而酪氨酸样C3可以被去除或积累。蛋白质样成分的Pb(II)结合通常较弱,但在某些降解组中增强,这可能与腐殖质样成分的竞争降低有关。绑定参数与DOM索引显著相关,腐殖质样成分的光降解占主导地位,但酪氨酸样成分的季节性变化占主导地位。这些结果对于理解水生环境中DOM-金属相互作用变化的关键机制具有重要意义。
    Dissolved organic matter (DOM) is very important in determining the speciation, behaviors, and risk of metal pollutants in aquatic ecosystems. Photochemical and microbial degradation are key processes in the cycling of DOM, yet their effects on the DOM-Pb(II) interaction remain largely unknown. This was studied by examining the complexation of river DOM with Pb(II) after degradation, using fluorescence quenching titration and excitation-emission matrices-parallel factor analysis (EEMs-PARAFAC). Three humic-like and two protein-like components were identified, with strong removals of humic-like components and decreasing average molecular weight and humification degree of DOM by photo- and photo-microbial degradation. The changes in humic-like abundance and structure resulted in notable weakening of their interaction with Pb(II). The tryptophan-like C2 was also mainly removed by photo-degradation, while the tyrosine-like C3 could be either removed or accumulated. The Pb(II)-binding of protein-like components was generally weaker but was enhanced in some degradation groups, which might be related to the lowering competition from humic-like components. The binding parameters correlated significantly with the DOM indices, which were dominated by photo-degradation for humic-like components but by seasonal variations for the tyrosine-like component. These results have implications for understanding the key mechanisms underlying the variability of the DOM-metal interaction in aquatic environments.
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  • 文章类型: Journal Article
    为了有效和高效地利用催化剂,必须提高光催化选择性。在这项研究中,以RB-19为模板,通过沉淀聚合法成功合成了分子印迹聚合物包覆的铁掺杂二氧化钛(Fe-TiO2@MIP)纳米复合材料。合成的纳米复合材料(Fe-TiO2@MIP和Fe-TiO2@NIP)通过傅里叶变换红外光谱(FT-IR)进行了表征,原子力显微镜(AFM),场发射扫描电子显微镜(FESEM)与能量色散X射线(EDX),X射线衍射(XRD)透射电子显微镜(TEM),X射线光电子能谱(XPS),Brunauer-EMMETT-Teller(BET),和紫外可见分光光度法。优化的结合实验揭示了RB-19的5.0的高印迹因子。Fe-TiO2@MIP的催化降解效率和选择性从母体Fe-TiO2的70%和Fe-TiO2@NIP的76%提高到RB-19的几乎完全降解。与其他竞争性染料相比,RB-19具有出色的降解选择性。最后,通过ESI-MS对未降解和降解的RB-19的分析表明,存在与所提出的降解机理非常吻合的不同中间体。该研究为目标污染物的选择性光降解开辟了新的可能性,最终可能导致光催化剂的有效使用。
    Improvement in the photocatalytic selectivity is imperative for the effective and efficient utilization of catalysts. In this study, a molecularly imprinted polymer-coated iron-doped titanium dioxide (Fe-TiO2@MIP) nanocomposite was successfully synthesized by precipitation polymerization while using RB-19 as a template. The synthesized nanocomposites (Fe-TiO2@MIP and Fe-TiO2@NIP) were characterized by Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) with energy dispersive X-ray (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-EMMETT-Teller (BET), and UV-visible spectrophotometry. The optimized binding experiments revealed a high imprinting factor of 5.0 for RB-19. The catalytic degradation efficiency and selectivity of Fe-TiO2@MIP enhanced to almost complete degradation of RB-19 from 70% for the parent Fe-TiO2 and 76% for Fe-TiO2@NIP. An outstanding degradation selectivity of RB-19 was achieved compared to other competitive dyes. Finally, the analysis of the non-degraded and degraded RB-19 by ESI-MS revealed the presence of different intermediates that fits well with the proposed degradation mechanism. The study opens new possibilities of selective photo-degradation of targeted contaminants that may ultimately lead to efficient use of photocatalysts.
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  • 文章类型: Journal Article
    有限的光吸收和快速的光生载流子复合对光催化剂的实际应用提出了重大挑战。在这项研究中,我们采用了一种有效的方法,将慢光子效应与Z方案电荷转移相结合,以增强抗生素的光降解性能。具体来说,我们通过简单的一步法将0DZnIn2S4量子点(QD)整合到3D分层反蛋白石(IO)TiO2结构中。这种组合增强了可见光的吸收并为有效的光降解提供了丰富的活性表面。此外,ZnIn2S4量子点与IO-TiO2形成人工Z方案体系,促进载流子的分离和迁移。为了与IO-TiO2实现更好的能带对准,我们将Ag掺杂到ZnIn2S4QD(Ag:ZISQD)中以调节其能级。通过对ZnIn2S4量子点不同Ag含量的研究,我们发现Ag(2.0):ZISQDs/IO-TiO2具有最佳的光降解性能,其降解速率分别比ZnIn2S4QDs和IO-TiO2高19.5和14.8倍。这项研究为提高IO-TiO2的光催化能力和扩大其未来的应用提供了重要的见解。
    Limited light absorption and rapid photo-generated carriers\' recombination pose significant challenges to the practical applications of photocatalysts. In this study, we employed an efficient approach by combining the slow-photon effect with Z-scheme charge transfer to enhance the photo-degradation performance of antibiotics. Specifically, we incorporated 0D ZnIn2S4 quantum dots (QDs) into a 3D hierarchical inverse opal (IO) TiO2 structure through a facile one-step process. This combination enhanced the visible light absorption and provided abundant active surfaces for efficient photo-degradation. Moreover, the ZnIn2S4 QDs formed an artificial Z-scheme system with IO-TiO2, facilitating the separation and migration of charge carriers. To achieve a better band alignment with IO-TiO2, we doped Ag into the ZnIn2S4 QDs (Ag: ZIS QDs) to adjust their energy levels. Through an investigation of the different Ag contents in the ZnIn2S4 QDs, we found that the optimal photo-degradation performance was achieved with Ag (2.0): ZIS QDs/IO-TiO2, exhibiting degradation rates 19.5 and 14.8 times higher than those of ZnIn2S4 QDs and IO-TiO2, respectively. This study provides significant insights for elevating the photocatalytic capabilities of IO-TiO2 and broadening its prospective applications.
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