Photocatalytic

光催化
  • 文章类型: Journal Article
    二硫键,尤其是不对称的二硫键,在生物活性和药物分子中具有重要的应用,但是由于效率和选择性问题,不对称二硫键的合成仍然具有挑战性。在这里,这项工作利用蒽醌(AQ)和环三膦腈通过亲核取代反应来合成有机聚合物(ANTH-AMI),该聚合物结合了邻聚醌(邻聚醌)氧化还原中心。蒽醌分子起氧化还原中心的作用,能够接受光诱导的电子并随后转移它们以引发电子偶联的氢化反应(AQ到AQH)。此外,邻聚醌氧化还原位点的接近促进了不对称二硫键形成的催化。因此,ANTH-AMI光催化剂表现出优异的产率(高达82%),基材多功能性,循环稳定性,以及在促进硫醇不对称偶联反应方面的可扩展制备。这项工作为设计具有相邻多个氧化还原中心的有机聚合物光催化剂提供了解决方案,用于交叉偶联反应。
    Disulfide bonds, especially unsymmetric disulfide bonds, have important applications in bioactivity and drug molecules, but the synthesis of unsymmetric disulfide bonds remains challenging due to efficiency and selectivity issues. Herein, this work utilizes anthraquinone (AQ) and cyclictriphosphonononitrile through a nucleophilic substitution reaction to synthesize an organic polymer (ANTH-AMI) that incorporates an ortho-polyquinone (o-polyquinone) redox center. The anthraquinone molecule functions as a redox center, capable of accepting photoinduced electrons and subsequently transferring them to initiate an electron-coupled hydrogenation reaction (AQ to AQH). Moreover, the proximity of the o-polyquinone redox sites facilitates the catalysis of unsymmetric disulfide bond formation. Consequently, the ANTH-AMI photocatalysts demonstrate exceptional yields (up to 82 %), substrate versatility, cycling stability, and scalable preparation in promoting unsymmetric coupling reactions of thiol. This work offers a solution for designing organic polymer photocatalysts with adjacent multiple redox centers for cross-coupling reactions.
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  • 文章类型: Journal Article
    光催化分子被认为是抗生素对抗多药耐药细菌感染的最有希望的替代之一。然而,强烈的激子效应极大地限制了它们在抗菌性能方面的效率。受界面偶极效应的启发,设计并合成了Ti3C2MXene修饰的光催化分子(MTTTPyB),以提高光照射下光生载流子的产率。Ti3C2和MTTTPyB之间的能级对齐导致形成界面偶极,这可以为载流子的分离提供动力。在偶极子电场的作用下,这些光生电子可以快速迁移到Ti3C2一侧,以提高光生电子和空穴的分离效率。因此,在光照射下,可以利用更多的电子来产生活性氧(ROS)。因此,金黄色葡萄球菌可达到97.04%以上的杀灭效率(S.当MTTTPyB/Ti3C2的浓度为50ppm时,在660nm照射15min。使用由MTTTPyB/Ti3C2制成的微针(MN)贴片治疗皮下细菌感染。这种有机-无机界面的设计提供了一种有效的方法,可以最大程度地减少分子的激子效应,进一步拓展了无机/有机杂化材料的高效光疗平台。
    Photocatalytic molecules are considered to be one of the most promising substitutions of antibiotics against multidrug-resistant bacterial infections. However, the strong excitonic effect greatly restricts their efficiency in antibacterial performance. Inspired by the interfacial dipole effect, a Ti3C2 MXene modified photocatalytic molecule (MTTTPyB) is designed and synthesized to enhance the yield of photogenerated carriers under light irradiation. The alignment of the energy level between Ti3C2 and MTTTPyB results in the formation of an interfacial dipole, which can provide an impetus for the separation of carriers. Under the role of a dipole electric field, these photogenerated electrons can rapidly migrate to the side of Ti3C2 for improving the separation efficiency of photogenerated electrons and holes. Thus, more electrons can be utilized to produce reactive oxygen species (ROS) under light irradiation. As a result, over 97.04% killing efficiency can be reached for Staphylococcus aureus (S. aureus) when the concentration of MTTTPyB/Ti3C2 was 50 ppm under 660 nm irradiation for 15 min. A microneedle (MN) patch made from MTTTPyB/Ti3C2 was used to treat the subcutaneous bacterial infection. This design of an organic-inorganic interface provides an effective method to minimize the excitonic effect of molecules, further expanding the platform of inorganic/organic hybrid materials for efficient phototherapy.
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  • 文章类型: Journal Article
    开发用于近红外(NIR)光驱动光催化的有效多光子吸收(MPA)材料具有重要意义。在这项研究中,我们将两个多支化环金属化铱(III)模块与MPA惰性金属有机骨架(MOFs)结合在一起,以发挥MPA的作用。随后,用Co(II)和透明质酸(HA)进一步修饰MOFs,以制造MINCH和MISCH,分别。通过引入八极分子并扩展缀合,MISCH表现出更大的MPA横截面,用于有效的NIR光吸收和改进的载流子转移,导致出色的近红外光驱动多光子光催化制氢。此外,HA修饰使MISCH能够实现针对癌细胞的特定多光子光催化氢治疗.这项研究为构建用于NIR光驱动光催化的高活性MPA材料提供了有价值的见解,为氢疗法在肿瘤治疗中提供了一个潜在的平台。
    The development of effective multiphoton absorption (MPA) materials for near-infrared (NIR) light-driven photocatalysis holds great significance. In this study, we incorporated two multibranched cyclometallated iridium(III) modules with varying degrees of conjugation onto MPA-inert metal-organic frameworks (MOFs) to active MPA performance. Subsequently, the MOFs were further modified with Co(II) and hyaluronic acid (HA) to fabricate MINCH and MISCH, respectively. By introducing octupolar molecules and expanding the conjugation, MISCH exhibited a larger MPA cross section for efficient NIR light absorption and improved carrier transfer, leading to outstanding NIR light-driven multiphoton photocatalytic hydrogen production. Moreover, the HA modification enabled MISCH to achieve specific multiphoton photocatalytic hydrogen therapy for cancer cells. This study provides valuable insights into constructing highly active MPA materials for NIR light-driven photocatalysis, presenting a potential platform for hydrogen therapy in tumor treatment.
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  • 文章类型: Journal Article
    作为水分解光催化H2生产的潜在候选者,Ta2O5催化剂具有合适的导带和价带位置,但是电荷转移能力差,这严重限制了其光催化性能的提高。这里,开发了一种简便且环保的水热法,用于使用新鲜沉淀的钽酸作为前体制造一维(1D)Ta2O5纳米棒。提出了一种用于生长Ta2O5纳米棒的定向附着机制。此外,将目前的合成方法进一步扩展到九种碱性钽酸盐和碱土金属钽酸盐纳米结构的直接合成,表明了它的普遍适用性。在1DTa2O5纳米棒上,光催化H2产生的活性显着提高。Ta2O5纳米棒的改进的光催化H2生产活性主要归因于其一维纳米棒结构具有高结晶度和大的表面积以及优异的电荷转移效率。
    As a potential candidate for photocatalytic H2 production from water splitting, Ta2O5 catalyst presents suitable conduction and valence band positions, but suffers from poor charge transfer ability, which seriously limits its photocatalytic performance enhancement. Here, a facile and eco-friendly hydrothermal method was developed for the fabrication of one-dimensional (1D) Ta2O5 nanorods using the freshly precipitated tantalic acids as the precursors. An oriented attachment mechanism was proposed for the growth of Ta2O5 nanorods. Moreover, the present synthetic approach was further extended to direct synthesis of nine kinds of alkaline tantalates and alkaline-earth tantalates nanostructures, suggesting its general applicability. A significant increase in activity in photocatalytic H2 production was revealed on 1D Ta2O5 nanorods. The improved photocatalytic H2 production activity of Ta2O5 nanorods was mainly attributed to its 1D nanorods structure with high crystallization and large specific surface areas as well as excellent charge transfer efficiency.
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  • 文章类型: Journal Article
    化石燃料的脱硫是减少环境中硫含量的关键过程。这是大气污染的主要原因。传统的脱硫技术,虽然有效,通常涉及高能耗和使用苛刻的化学品。最近,光催化脱硫已经成为一种有前途的,生态友好的替代品,利用光催化剂特别是半导体异质结的潜力来提高光催化效率。本文综述了光催化脱硫反应的意义和机理,各种异质结的设计,如传统的,p-n,Z方案和S方案,它们的电荷转移机理和性质及其对光催化脱硫活性的贡献。异质结,通过组合不同的半导体材料形成,有利于有效的电荷分离和扩大光吸收范围,从而提高可见光下的光催化性能。此外,本文对近年来异质结系统在光催化脱硫活性领域的研究进展进行了详细的讨论和总结。还探讨了这一特定领域的当前局限性和挑战。最后对异质结光催化脱硫的未来研究方向和潜在的工业应用进行了展望,强调其在实现清洁能源生产和环境可持续性方面的作用。
    Desulphurization of fossil fuels is a critical process in reducing the sulphur content from environment, which is a major contributor to atmospheric pollution. Traditional desulphurization techniques, while effective, often involve high energy consumption and the use of harsh chemicals. Recently, photocatalytic desulphurization has emerged as a promising, eco-friendly alternative, leveraging the potential of photocatalysts especially semiconductor heterojunctions to enhance photocatalytic efficiency. This review comprehensively discusses the significance and mechanism of photocatalytic desulphurization reactions, designing of various heterojunctions such as conventional, p-n, Z-scheme and S-scheme, their charge transfer mechanism and properties and their contribution to the photocatalytic desulphurization activity. Heterojunctions, formed by combining different semiconductor materials, facilitate efficient charge separation and broaden the light absorption range, thereby improving the photocatalytic performance under visible light. Furthermore, the recent advancements in the heterojunction systems in the field of photocatalytic desulphurization activity have been discussed in detail and summarized. The current limitations and challenges in this particular field are also explored. The paper concludes with an outlook on future research directions and the potential industrial applications of heterojunction-powered photocatalytic desulphurization, emphasizing its role in achieving cleaner energy production and environmental sustainability.
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  • 文章类型: Journal Article
    在纯H2O介质中光催化还原CO2以生产化学品为同时缓解能源和环境危机提供了有吸引力的途径。然而,光生电荷载流子的快速复合在这个有前途的领域中提出了重大挑战。异质结工程已成为解决这一难题的有效方法。这里,通过将2DNiAl层状双氢氧化物(NAL)装饰到溴化铋(BOB)上,我们已经创建了一个S方案异质结(N1B1复合材料)。该催化剂提供102.30μmolg-1的CO2-CO产率,选择性为100%。紫外光电子能谱(UPS)和原位辐照X射线光电子能谱(ISI-XPS)表明,在光辐照下,电荷从BOB有效地转移到2D-NAL。与裸露的2D-NAL和BOB相比,设计的N1B1异质结的内部电场强度增加了7.3倍和2.1倍,分别,这应该对改进的费用迁移负责。此外,脉冲化学吸附和原位漫反射红外傅里叶变换光谱(DRIFTS)显示,在N1B1复合材料上存在多个具有活化OCO键的碳酸酯中间体,*CO2-被确定为产生CO的最关键物种。
    Photocatalytic reduction of CO2 in pure H2O media to produce chemicals presents an appealing avenue for simultaneously alleviating energy and environmental crises. However, the rapid recombination of photogenerated charge carriers presents a significant challenge in this promising field. Heterojunction engineering has emerged as an effective approach to address this dilemma. Here, by decorating 2D NiAl-layered double hydroxides (NAL) onto bismuth oxybromide (BOB), we have created a S-scheme heterojunction (N1B1 composite). This catalyst affords CO2-to-CO yields of 102.30 μmol g-1 with a selectivity of 100 %. Ultraviolet photoelectron spectroscopy (UPS) and in-situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) reveal that charge transfer occurs efficiently from BOB to 2D-NAL upon light irradiation. The designed N1B1 heterojunction achieves 7.3-fold and 2.1-fold increase in the internal electric field strength compared to bare 2D-NAL and BOB, respectively, which should be accountable for the improved charge migration. Additionally, pulsed chemisorption and in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) show the presence of multiple carbonate intermediates with activated OCO bonds upon N1B1 composite, with *CO2- being identified as the most crucial species for CO production.
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  • 文章类型: Journal Article
    光催化膜对于解决膜污染问题至关重要。然而,催化剂在膜上的接枝量往往成为制约膜自清洁能力的关键因素。为了应对挑战,这篇手稿提出了一种解决膜污染的方法,具有氧化铋(Bi2O3)和丙烯酸(AA)的高接枝率,显著的污染物降解能力,和可重用性。通过吸附/沉积和紫外接枝聚合将纳米Bi2O3和丙烯酸附着在聚偏氟乙烯膜上,制备了由聚偏氟乙烯氧化铋和丙烯酸(PVDF-g-BA)制成的高光催化自清洁微滤膜。与纯膜和纯丙烯酸接枝膜(PVDF-g-AA)相比,0.5%氧化铋接枝改性膜不仅提高了接枝率和过滤性能,还具有较高的自洁能力。此外,该膜在可见光照射下对有机染料甲基紫2B的降解效果非常显著,降解率达到90%,12小时后几乎完全降解。最后,经过反复过滤和光催化,膜仍然可以显著降解污染物并且可以重复使用。
    Photocatalytic membranes are crucial in addressing membrane fouling issues. However, the grafting amount of the catalyst on the membrane often becomes a key factor in restricting the membrane\'s self-cleaning capability. To address the challenge, this manuscript proposes a method for solving membrane fouling, featuring high grafting rates of bismuth oxide (Bi2O3) and acrylic acid (AA), significant contaminant degradation capability, and reusability. A highly photocatalytic self-cleaning microfiltration membrane made of polyvinylidene fluoride bismuth oxide and acrylic acid (PVDF-g-BA) was prepared by attaching nano Bi2O3 and acrylic acid onto the polyvinylidene fluoride membrane through adsorption/deposition and UV grafting polymerization. Compared with pure membranes and pure acrylic grafted membranes (PVDF-g-AA), the modified membrane grafted with 0.5% bismuth oxide not only improves the grafting rate and filtration performance, but also has higher self-cleaning ability. Furthermore, the degradation effect of this membrane on the organic dye methyl violet 2B under visible light irradiation is very significant, with a degradation rate reaching 90% and almost complete degradation after 12 h. Finally, after repeated filtration and photocatalysis, the membrane can still significantly degrade contaminants and can be reused.
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  • 文章类型: Journal Article
    提出了具有光催化性能的聚乙烯醇(PVA)/TiO2/胶体光子晶体(CPC)薄膜,其中TiO2纳米颗粒被引入PVA凝胶网络中。这种PVA/TiO2/CPC膜具有用PVA/TiO2复合凝胶支撑的三维周期性结构。CPC独特的结构颜色可以指示材料制备的过程,吸附,和解吸。使用光纤光谱法可以更准确地确定CPC的衍射峰的偏移。PVA/TiO2/CPC膜催化剂在4h内对亚甲基蓝(MB)的降解率为77~90%,而4小时内PVA/TiO2薄膜对MB的降解率为33%,表明光子晶体结构的有效性是整体结构的2.3〜2.7倍。
    Polyvinyl alcohol (PVA)/TiO2/colloidal photonic crystal (CPC) films with photocatalytic properties are presented, where TiO2 nanoparticles were introduced into the PVA gel network. Such PVA/TiO2/CPC films possess three-dimensional periodic structures that are supported with a PVA/TiO2 composite gel. The unique structural color of CPCs can indicate the process of material preparation, adsorption, and desorption. The shift of diffraction peaks of CPCs can be more accurately determined using fiber-optic spectroscopy. The effect of the PVA/TiO2/CPC catalyst films showed better properties as the degradation of methylene blue (MB) by the PVA/TiO2/CPC film catalyst in 4 h was 77~90%, while the degradation of MB by the PVA/TiO2 film was 33% in 4 h, indicating that the photonic crystal structure was 2.3~2.7 times more effective than that of the bulk structure.
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  • 文章类型: Journal Article
    通过溶胶-凝胶法制备铁酸钙纳米颗粒。X射线衍射,扫描电子显微镜,和紫外-可见光谱分析材料。空间群Pnma中存在正交相。有四种技术用于计算平均微晶尺寸。使用ImageJ软件,颗粒聚集并确定其尺寸。使用能量色散X射线(EDX)分析,确定了材料的组成。2.29eV被确定为带隙。振动测试磁力计(VSM)为材料的磁性提供了解释。带隙能量的降低导致孔雀石绿染料在150分钟内浓度为15mg/L时降解90%,具有四个周期的可重用性。
    以甘蓝叶提取物为燃料,通过溶胶-凝胶辅助燃烧法成功合成了铁酸钙纳米颗粒。据作者所知,以前在学术文献中没有报道过使用甘蓝叶提取物合成铁酸钙纳米颗粒的案例研究。该方法在不使用任何化学燃料剂的情况下是成本有效且方便的。合成的材料可以有效去除孔雀石绿染料,常用于丝绸和尼龙行业的染色,从解决方案。对MB的去除效率超过90%。该材料表现出优异的稳定性和染料吸附的可重用性。用伪一级动力学模型对结果进行了验证。
    The calcium ferrite nanoparticles were made by the sol-gel process. X-ray diffraction, a scanning electron microscope, and UV-vis spectroscopy were used to analyze the material. There is an orthorhombic phase in the space group Pnma. There were four techniques used to calculate the average crystallite size. Using ImageJ software, the particles were aggregated and their size was ascertained. Using energy-dispersive X-ray (EDX) analysis, the composition of the material was ascertained. 2.29 eV was determined to be the band gap. Vibrating test magnetometer (VSM) provided an explanation for the materials\' magnetic property. A decreased band gap energy is responsible for the 90% degradation of malachite green dye at a concentration of 15 mg/L in 150 min, with a four-cycle reusability.
    Calcium ferrite nanoparticles were successfully synthesized by sol–gel assisted combustion method using leaf extract of Brassica oleracea as fuel.To the best of the author’s knowledge, no such case study that reports the synthesis of calcium ferrite nanoparticles by using leaf extract of Brassica oleracea is previously reported in academic literature.The method is cost-effective and convenient without the use of any chemical fuel agents.The synthesized prepared material efficiently removes malachite green dye, commonly used in industries for dyeing silk and nylon, from the solution.More than 90 % removal efficiency for MB.The material displayed excellent stability and reusability for dyes adsorption.Results were validated with pseudo-first-order kinetic model.
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  • 文章类型: Journal Article
    As(III)的毒性比As(V)大得多,同时在矿物表面显示出明显较低的亲和力。H2O2在锐钛矿表面上将As(III)氧化为As(V)提供了一种有吸引力的污染控制途径。并通过DFTD3方法阐明了化学催化和光催化机理。锐钛矿作为支持的影响,O2c/O3c空缺,光辐照也得到了解决。As(III)在各种反应条件下的氧化通过双电子转移导致As(V),而能量势垒差异很大,并且随着1.80(直接氧化)>1.35(锐钛矿作为支撑)>1.24(O3c空位)>0.50(化学催化)>0.28(光催化)≥0.26(O2c空位)eV而下降。锐钛矿作为载体通过与H2O2/As(OH)3键合和电子转移促进反应,及其在化学催化过程中的紧密参与会产生TiOOH活性位点,该活性位点会导致As(III)氧化在周围环境下轻松进行。TiOOH以两种形式存在(单齿和双齿单核),对化学催化至关重要,而其对O3c空位的破坏对As(III)氧化表现出强烈的不利影响。光照射容易产生OH•自由基,与基于Ti(H2O2)活性位点的新近提出的机制相比,相应的机制似乎是合理的,但较不优选。许多表面原子之间的协同作用导致对O2c空位和光催化的优异活性。结果为H2O2将As(III)氧化为As(V)提供了全面的了解,并有助于设计减轻环境污染的As(III)氧化催化剂。
    As(III) is much more toxic than As(V) while shows apparently lower affinity at minerals surfaces. Oxidation of As(III) to As(V) by H2O2 over anatase surface provides an attractive avenue for pollution control, and the chemocatalytic and photocatalytic mechanisms are unraveled by means of the DFT + D3 approach. Impacts of anatase as support, O2c/O3c vacancy, photoirradiation are addressed as well. As(III) oxidation under various reaction conditions leads to As(V) through dual electron transfers, while energy barriers differ substantially and decline as 1.80 (direct oxidation) > 1.35 (anatase as support) > 1.24 (O3c vacancy) > 0.50 (chemocatalysis) > 0.28 (photocatalysis) ≥ 0.26 (O2c vacancy) eV. Anatase as support promotes the reaction through bonding with H2O2/As(OH)3 and electron transfers, and its close participation during chemocatalysis produces the TiOOH active site that causes As(III) oxidation to proceed facilely under ambient circumstances. TiOOH exists in two forms (monodentate and bidentate mononuclear) and is critical for chemocatalysis, while its destruction for O3c vacancy exhibits strongly adverse effects to As(III) oxidation. Photoirradiation readily generates the OH• radicals, and corresponding mechanism is plausible while less preferred than the newly posed mechanism based on the Ti(H2O2) active site. Synergism among a number of surface atoms conduces to the superior activity for O2c vacancy and photocatalysis. Results provide a comprehensive understanding for As(III) oxidation to As(V) by H2O2, and facilitate catalysts design for As(III) oxidation that alleviates environmental pollution.
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