Photocatalysis

光催化
  • 文章类型: Journal Article
    已开发出可见光引发的能量转移使能的自由基环化,用于多环γ-硫化物衍生物的发散合成。该反应提供了一种替代和快速获得苯并稠合γ-硫化物骨架的途径,γ-内酯和γ-磺内酯的类似物,并具有良好的功能组兼容性,温和的反应条件和优异的非对映选择性。该方法的稳健性和应用潜力也已通过两个克规模反应和多环磺内酯的合成成功地展示。机理研究表明,主要通过可能的能量转移使分子内自由基均裂取代或氢原子转移过程进行转化。
    A visible-light-initiated energy-transfer enabled radical cyclization for the divergent synthesis of polycyclic γ-sultine derivatives has been developed. The reaction provides an alternative and expeditious access to benzofused γ-sultine frameworks, the analogues of γ-lactones and γ-sultones, and features good functional group compatibility, mild reaction conditions and excellent diastereoselectivity. The robustness and application potential of this method have also been successfully displayed by two gram-scale reactions and the synthesis of polycyclic sultones. Mechanistic studies indicated the transformations through a possible energy-transfer enabled intramolecular radical homolytic substitution or hydrogen atom transfer process mainly.
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  • 文章类型: Journal Article
    在本研究中,我们研究了表面氟(F)对TiO2对甲苯光催化氧化(PCO)的影响。制备并测试了不同F含量的TiO2。发现随着F含量的增加,甲苯转化率先升高后降低。然而,CO2矿化效率呈现相反趋势。根据特征,我们揭示了F取代TiO2的表面羟基形成Ti-F的结构。TiO2上适量的表面Ti-F的存在大大增强了光生载流子的分离,这促进了·OH的产生并提高了甲苯PCO的活性。进一步表明,仅·OH的增加促进了甲苯向含环中间体的转化,导致中间体的积累,然后反过来抑制·OH的产生,导致CO2矿化效率降低。以上结果可为甲苯氧化光催化剂的合理设计提供指导。
    In the present study, we investigated the influence of surface fluorine (F) on TiO2 for the photocatalytic oxidation (PCO) of toluene. TiO2 modified with different F content was prepared and tested. It was found that with the increasing of F content, the toluene conversion rate first increased and then decreased. However, CO2 mineralization efficiency showed the opposite trend. Based on the characterizations, we revealed that F substitutes the surface hydroxyl of TiO2 to form the structure of Ti-F. The presence of the appropriate amount of surface Ti-F on TiO2 greatly enhanced the separation of photogenerated carriers, which facilitated the generation of ·OH and promoted the activity for the PCO of toluene. It was further revealed that the increase of only ·OH promoted the conversion of toluene to ring-containing intermediates, causing the accumulation of intermediates and then conversely inhibited the ·OH generation, which led to the decrease of the CO2 mineralization efficiency. The above results could provide guidance for the rational design of photocatalysts for toluene oxidation.
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  • 文章类型: Journal Article
    混合维范德华异质结(MD-vdWhs),以卓越的电子转移和电荷分离能力而闻名,在光催化方面仍未充分开发。在这项研究中,我们利用分子间π→π*和D-π-A双通道的协同作用制造了新型MD-vdWhs。由于协同效应,它表现出优越的电子转移和离域能力,从而提高其光催化性能。最佳光催化剂可在15min内降解20mg/L四环素(TC)98.78%。此外,我们介绍了一种研究光电子转移路径的新证明策略,创造性地展示了协同双通道效应,这可以归因于羰基密度和光激发程度。值得注意的是,即使在低功率光源下,它在短短7分钟内实现了大肠杆菌的完全灭活,远远超过当前的前沿研究。这一理论框架有望在相关研究中得到更广泛的应用。
    Mixed-dimensional van der Waals heterojunctions (MD-vdWhs), known for exceptional electron transfer and charge separation capabilities, remain underexplored in photocatalysis. In this study, we leveraged the synergistic effect of intermolecular π → π* and D-π-A dual channels to fabricate novel MD-vdWhs. Owing to the synergistic effect, it exhibits superior electron transfer and delocalization ability, thereby enhancing its photocatalytic performance. The Optimal photocatalyst can degrade 98.78 % of 20 mg/L tetracycline (TC) within 15 min. Additionally, we introduced a novel proof strategy for investigating the photoelectron transfer path, creatively demonstrating the synergistic dual channels effect, which can be attributed to the carbonyl density and light-excitation degree. Notably, even under low-power light sources, it achieved complete inactivation of Escherichia coli within just 7 mins, far surpassing current cutting-edge research. This theoretical framework holds promise for broader applications within related studies.
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  • 文章类型: Journal Article
    充分利用磷光光捕获系统(PLHSs)捕获的能量和能量转移过程中的可调谐光致发光来实现多种应用仍然是PLHSs研究的挑战。在这项研究中,我们已经成功地构建了一个具有可调多色发光和光敏剂类型的高效转换的高效PLHS,可进一步用于光催化有机转化,信息防伪和存储。BDBP-CB的超分子聚合物[8],由葫芦[8]脲(CB[8])和4-(4-溴苯基)-吡啶衍生物(BDBP)产生,实现磷光发射和发光颜色的变化。值得注意的是,实现了白光发射,并利用可调发光颜色的应用构建了逻辑门系统。更有趣的是,PLHS可以通过采用BDBP-CB[8]作为能量供体来构建,磺酰罗丹明101(SR101)和Cyanine5(Cy5)作为能量受体,这导致了显著可调的多色光致发光来实现信息存储。此外,我们还发现,BDBP-CB[8]可以作为II型光敏剂,用于在水性环境中苯乙烯的光氧化过程中有效产生单线态氧(1O2),实现了高达89%的显著产出率。特别是,与II型光敏剂BDBP-CB产生的1O2相比[8],PLHS的构建可以有效地将II型光敏剂转化为I型光敏剂,并有效地产生超氧阴离子自由基(O2•-),可用于水溶液中的光催化交叉脱氢偶联(CDC)反应,收率为90%。因此,我们创造了一个PLHS,不仅实现了信息防伪和存储的可调多色发射,而且还实现了不同类型光催化氧化反应的活性氧(ROS)的转化。
    Making full use of the captured energy by phosphorescence light-harvesting systems (PLHSs) and the tunable photoluminescence in energy transfer process to realize the multiple applications is still the challenge of PLHSs research. In this study, we have successfully constructed a highly effective PLHS with tunable multicolor luminescence and efficient conversion of photosensitizer types, which can further be used in photocatalytic organic conversion, information anti-counterfeiting and storage. The supramolecular polymer of BDBP-CB[8], which is generated by cucurbit[8]uril (CB[8]) and 4-(4-bromophenyl)-pyridine derivative (BDBP), realizes a phosphorescence emission and a change in luminescence color. Notably, white light emission was achieved and the logic gate systems were constructed utilizing the application of adjustable luminescence color. More interestingly, PLHS can be constructed by employing BDBP-CB[8] as energy donors, Sulforhodamine 101 (SR101) and Cyanine5 (Cy5) as energy acceptors, which results in a remarkably tunable multicolor photoluminescence to achieve the information storage. Furthermore, we have also found that BDBP-CB[8] can serve as type II photosensitizer for the effective production of singlet oxygen (1O2) during the photooxidation process of styrene in aqueous environments, attaining a remarkable output rate reaching as high as 89 %. Particularly, compared with 1O2 produced by type II photosensitizer BDBP-CB[8], the construction of PLHS can effectively convert type II photosensitizer to type I photosensitizer and efficiently generate superoxide anion radical (O2•-), which can be used for photocatalytic cross-dehydrogenative coupling (CDC) reaction in the aqueous solution with a yield of 90 %. Thus, we have created a PLHS that not only achieves tunable multicolor emission for information anti-counterfeiting and storage, but also realizes the conversion of reactive oxygen species (ROS) for different types photocatalytic oxidation reactions.
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  • 文章类型: Journal Article
    使用溶胶-凝胶制备了负载有二氧化钛(TiO2)和石墨氮化碳(g-C3N4)的纤维素基碳气凝胶(CTN),冷冻干燥,和高温碳化方法。溶胶-凝胶的形成是通过使用精制造纸纸浆的一锅法进行的,钛酸四丁酯,和尿素为原料和锂蒙脱石为交联和增强剂。由于锂蒙脱石的交联能力,碳化气凝胶保持多孔结构并具有大的比表面积和低密度(0.0209g/cm3)。XRD分析,XPS,拉曼光谱表明,二氧化钛(TiO2)和石墨碳氮化物(g-C3N4)在CTN中均匀分布,TEM和SEM观察表明CTN具有均匀分布的三维多孔结构。根据CTN对罗丹明B的降解能力,测定了CTN的光催化活性。120min后,在可见光下的去除率达到89%。此外,CTN在5个循环后仍然稳定。所提出的催化剂在可见光条件下表现出优异的光催化性能。
    A cellulose-based carbon aerogel (CTN) loaded with titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) was prepared using sol-gel, freeze-drying, and high-temperature carbonization methods. The formation of the sol-gel was carried out through a one-pot method using refining papermaking pulp, tetrabutyl titanate, and urea as raw materials and hectorite as a cross-linking and reinforcing agent. Due to the cross-linking ability of hectorite, the carbonized aerogel maintained a porous structure and had a large specific surface area with low density (0.0209 g/cm3). The analysis of XRD, XPS, and Raman spectra revealed that the titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) were uniformly distributed in the CTN, while TEM and SEM observations demonstrated the uniformly distributed three-dimensional porous structure of CTN. The photocatalytic activity of the CTN was determined according to its ability to degrade rhodamine B. The removal rate reached 89% under visible light after 120 min. In addition, the CTN was still stable after five reuse cycles. The proposed catalyst exhibits excellent photocatalytic performance under visible light conditions.
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  • 文章类型: Journal Article
    光生电荷载流子的有效分离和强氧化性能可以提高光催化性能。这里,我们将紧密相连的S方案异质结的构造与活性晶体平面的暴露相结合,以制备g-C3N4/BiOBr,用于降解高浓度有机污染物。该策略有效地提高了光生载流子的分离效率和活性位点的数量。值得注意的是,合成的g-C3N4/BiOBr对各种有机污染物表现出优异的光催化降解活性,包括亚甲蓝(MB,90.8%),刚果红(CR,99.2%),和四环素(TC,89%)。此外,g-C3N4/BiOBr对MB的光催化降解性能在自然水质(自来水,湖水,河水),和宽pH范围(pH=4-10)。其优异的光催化活性归因于S方案异质结界面中g-C3N4和BiOBr之间的紧密连接,以及高活性(001)晶面的曝光。这些提高了光生载流子的分离效率,并保持其强大的氧化能力。这项工作提出了一种简单的方法,通过在异质结内紧密结合两种成分来改善电子和空穴的分离。
    The efficient separation of photogenerated charge carriers and strong oxidizing properties can improve photocatalytic performance. Here, we combine the construction of a tightly connected S-scheme heterojunction with the exposure of an active crystal plane to prepare g-C3N4/BiOBr for the degradation of high-concentration organic pollutants. This strategy effectively improves the separation efficiency of photogenerated carriers and the number of active sites. Notably, the synthesized g-C3N4/BiOBr displays excellent photocatalytic degradation activity towards various organic pollutants, including methylene blue (MB, 90.8%), congo red (CR, 99.2%), and tetracycline (TC, 89%). Furthermore, the photocatalytic degradation performance of g-C3N4/BiOBr for MB maintains 80% efficiency under natural water quality (tap water, lake water, river water), and a wide pH range (pH = 4-10). Its excellent photocatalytic activity is attributed to the tight connection between g-C3N4 and BiOBr in the S-scheme heterojunction interface, as well as the exposure of highly active (001) crystal planes. These improve the efficiency of the separation of photogenerated carriers, and maintain their strong oxidation capability. This work presents a simple approach to improving the separation of electrons and holes by tightly combining two components within a heterojunction.
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  • 文章类型: Journal Article
    随着塑料需求和利用的不断升级,控制塑料污染已得到相当重视。在这些方法中,由于其节能和环保的特性,塑料的光催化再循环已成为塑料管理的一种有前途的方法。在过去的几年里,许多商业塑料类型的光催化转化已经付出了巨大的努力。这些令人鼓舞的努力预示着该领域的持续发展和应用。在这次审查中,综述了塑料光催化上循环的最新进展。首先介绍了塑料光催化解构的基本原理和原理。然后,我们总结了不同类型塑料的改造工作,包括聚烯烃,聚酯,和其他类型。最后,为塑料光催化上循环的发展提供了一些挑战和可能的解决方案。
    With the escalating demand and utilization of plastics, considerable attention has been given to controlling plastic pollution. Among these methodologies, photocatalytic upcycling of plastic has emerged as a promising method for plastic management due to its energy-saving and eco-friendly properties. In the past several years, great efforts have been devoted to the photocatalytic conversion of a variety of commercial plastic types. These encouraging endeavors foreshadow the continued progression and application in this field. In this review, recent advancements in the photocatalytic upcycling of plastics are reviewed. The fundamentals and principles of photocatalytic deconstruction of plastics are first introduced. Then, we summarize the works on the reforming of different types of plastic, including polyolefins, polyesters, and other types. Finally, some challenges and possible solutions are provided for the development of photocatalytic upcycling of plastics.
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  • 文章类型: Journal Article
    非常需要合理地设计和构建二维(2D)硫属化物的原子级异质界面,以克服缓慢的H2O活化过程,以实现有效的太阳能驱动的氢析出。在这里,一种新型的平面内2D/2D二硫化钼-二硫化铼(ReS2-MoS2)异质结构经过精心设计,可通过形成富含电子的Re(4-δ)和电子-缺陷的S(2-δ)位点来诱导活性位点的电荷自我调节。从而共同促进吸附的H2O分子的活化及其随后的H2析出。此外,通过先进的开尔文探针测量(KPFM)观察到,获得的平面内异质ReS2-MoS2纳米片可以有力地转移光激发电子以抑制光载流子复合,原位X射线光电子能谱(XPS)和飞秒瞬态吸收光谱(fs-TAS)。不出所料,获得的ReS2-MoS2/TiO2光催化剂在碱性/中性条件下可视化H2气泡时,H2的产生速率优于6878.3μmolh-1g-1。这项关于具有强自由电子相互作用的平面内2D/2D异质结构的工作为设计用于各种应用的新型高效催化剂提供了有希望的策略。
    The rationally designing and constructing atomic-level heterointerface of two-dimensional (2D) chalcogenides is highly desirable to overcome the sluggish H2O-activation process toward efficient solar-driven hydrogen evolution. Herein, a novel in-plane 2D/2D molybdenum disulfide-rhenium disulfide (ReS2-MoS2) heterostructure is well-designed to induce the charge self-regulation of active site by forming electron-enriched Re(4-δ)+ and electron-deficient S(2-δ)- sites, thus collectively facilitating the activation of adsorbed H2O molecules and its subsequent H2 evolution. Furthermore, the obtained in-plane heterogenous ReS2-MoS2 nanosheet can powerfully transfer photoexcited electrons to inhibit photocarrier recombination as observed by advanced Kelvin probe measurement (KPFM), in-situ X-ray photoelectron spectroscopy (XPS) and femtosecond transient absorption spectroscopy (fs-TAS). As expected, the obtained ReS2-MoS2/TiO2 photocatalyst achieves an outperformed H2-generation rate of 6878.3 μmol h-1 g-1 with visualizing H2 bubbles in alkaline/neutral conditions. This work about in-plane 2D/2D heterostructure with strong free-electron interaction provides a promising strategy for designing novel and efficient catalysts for various applications.
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  • 文章类型: Journal Article
    过氧化氢(H2O2)的人工光合作用是工业蒽醌工艺的有希望的替代方案。然而,在没有任何牺牲剂的情况下,合理制造用于生产H2O2的光催化剂仍然是一个巨大的挑战。在这里,成功合成了两种线性共轭聚合物(LCP),包括吡啶N官能化聚合物(DEB-N2)和吡啶N不含聚合物(DEB-N0)。DEB-N2显示增强的光捕获能力和在水中的良好分散性,导致H2O2的初始生成速率为3492μmolg-1h-1,并且在纯水中具有显着的光催化稳定性。此外,程序升温脱附(TPD)和密度泛函理论(DFT)分析表明,DEB-N2中的高电负性吡啶-N原子增强了氧分子的吸附亲和力,这促进了氧还原反应的发生,因此提高了光催化H2O2生产的性能。这项研究揭示了吡啶N在DEB-N2中的存在对光催化H2O2的产生有显著的影响,这表明对聚合物光催化剂的化学结构的精确操纵对于实现有效的太阳能到化学能转换至关重要。
    Artificial photosynthesis of hydrogen peroxide (H2O2) is a hopeful alternative to the industrial anthraquinone process. However, rational fabrication of the photocatalysts for the production of H2O2 without any sacrificial agents is still a formidable challenge. Herein, two kinds of linear conjugated polymers (LCPs) including pyridinic N functionalized polymer (DEB-N2) and pyridinic N non-contained polymer (DEB-N0) were successfully synthesized. DEB-N2 displays enhanced light capturing ability and good dispersion in water, leading to a substantial initial H2O2 generation rate of 3492μmol g-1h-1 as well as remarkable photocatalytic stability in pure water. Furthermore, the temperature programmed desorption (TPD) and density functional theory (DFT) analysis reveal that highly electronegative pyridine-N atoms in DEB-N2 boost the adsorption affinity of oxygen molecules, which facilitates the occurrence of the oxygen reduction reaction, therefore enhancing the performance of photocatalytic H2O2 production. This study unveils that the presence of pyridinic N in DEB-N2 has a significant impact on photocatalytic H2O2 production, suggesting the precise manipulation of the chemical structure of polymer photocatalysts is essential to achieve efficient solar-to-chemical energy conversion.
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  • 文章类型: Journal Article
    管状Co9S8/CdS异质结构已通过同时固定和原位还原策略通过在Co9S8纳米管上原位生长CdS成功合成。结果表明,这样获得的Co9S8/CdS摩尔比为1/10的异质结构可以显示出宽的光吸收边缘,尤其是在可见光下光催化还原Cr(VI)的能力大大提高。表征分析和实验结果表明,异质结构中Co9S8和CdS元素之间的界面静电场可以由于它们不同的费米能级而被构造。允许更多的高度还原性电子参与光催化反应。因此,由此获得的Co9S8/CdS(1/10)异质结构在20min内可达到100%的光催化还原效率,分别是原始CdS和Co9S8的两倍和四倍以上。此外,研究了还原Cr(VI)的可能的光催化反应机理,并发现遵循直接Z方案电荷转移途径。这种具有管状异质结构的复合光催化剂的新颖制造路线可能导致在环境治理过程中消除各种有害污染物的广泛实施。
    Tubular Co9S8/CdS heterostructures have been successfully synthesized by in-situ growing CdS onto Co9S8 nanotubes through a simultaneous immobilization and in-situ reduction strategy. It turned out that the so-obtained heterostructure with Co9S8/CdS molar ratio of 1/10 can display a broad light absorption edge and especially much enhanced capacity for photocatalytic reduction of Cr(VI) under visible light. The characterization analysis and experimental results suggested that an interfacial electrostatic field between Co9S8 and CdS elements in the heterostructure could be constructed due to their different Fermi levels, allowing for more quantities of highly reductive electrons to participate in the photocatalytic reaction. Therefore, the so-obtained Co9S8/CdS (1/10) heterostructures could achieve the photocatalytic reduction efficiency of 100% within 20 min, which was more than two and four times larger than that of pristine CdS and Co9S8, respectively. Moreover, the possible photocatalytic reaction mechanism for reducing Cr(VI) was investigated and found to follow the direct Z-scheme charge transfer pathway. This novel fabrication route for composite photocatalysts with tubular heterostructures could lead to the widespread implementations for the elimination of various harmful pollutants in the process of environmental governance.
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