Latest ArticlesCatalytic oxidation of soot is of great importance for emission control on diesel vehicles. In this work, a highly active Cs/Co/Ce-Sn catalyst was investigated for soot oxidation, and it was unexpectedly found that high-temperature calcination greatly improved the activity of the catalyst. When the calcination temperature was increased from 500 ℃ to 750 ℃, T50 decreased from 456.9 ℃ to 389.8 ℃ in a NO/O2/H2O/N2 atmosphere. Characterization results revealed that high-temperature calcination can promote the ability to transfer negative charge density from Cs to other metal cations in Cs/Co/Ce-Sn, which will facilitate the production of more oxygen defects and the generation of more surface-active oxygen species. Surface-active oxygen species are beneficial to the oxidation of NO to NO2, leading to the high yield of NO2 exploitation. Therefore, the Cs/Co/Ce-Sn catalyst calcined at 750 ℃ demonstrated higher activity than that calcined at 500 ℃. This work provides a pathway to prepare high efficiency catalysts for the removal of soot and significant insight into the effects of calcination on soot oxidation catalysts.
Zirconium-based metal-organic cages (Zr-MOCs) typically exhibit high stability, but their structural and application reports are scarce due to stringent crystallization conditions. We have successfully fluorinated the classical Zr-MOCs (ZrT-3) for the first time, obtaining the fluorinated MOCs (ZrT-3-F). Notably, ZrT-3-F not only inherits the high stability of its parent structure, but also acts as a catalyst for the effective oxidation of benzyl thioether for the first time. The reaction can reach a conversion rate of 99% in 6 h, and the selectivity reaches 95%, which far exceeds the non-fluorinated ZrT-3. This work proves that the specific functionalization of the classical Zr-MOCs can further expand their application potential, such as catalysis.
This review covers the structures of diterpenoids, including chain (72), monocyclic (9), labdane-type (67), clerodane-type (127) abietane-type (716), ent-kaurane-type (89), grayanane-type (331), ingenane-type (55), tigliane-type (154), daphnane-type (237), and aconitine-type diterpene alkaloids (265) with rich biological activities reported in 2013–2023. And the drugs in clinical use or under clinical investigation of diterpenoids and leading compounds were summarized.
Metal-organic frameworks (MOFs) with superior physicochemical properties have great potential for applications in chromatographic separation. However, currently popular methods for the synthesis of MOF-based silica composite materials usually require the use of harmful organic solvents and long-term high-temperature sealing reactions. In order to respond to the needs of green chromatography, it is urgent to develop a new green organic-solvent-free strategy for the synthesis of MOF@SiO2 composites. MIP-202 is a zirconium-MOF constructed from zirconium ion and l-aspartic acid, which features green synthesis as well as good hydrolytic stability and chemical stability. In this paper, SiO2-NH2 was first prepared in a hydrophilic deep eutectic solvent, and then an amino acid-based MOF material (MIP-202) was modified on the surface of the SiO2-NH2 in an aqueous solution to obtain a MIP-202@SiO2 composite material. The multi-mode separation performance of MIP-202@SiO2 as a promising liquid chromatographic stationary phase was particularly evaluated and the separation mechanisms were discussed. The MIP-202@SiO2 column exhibited excellent separation ability for aromatic positional isomers. In addition, chiral enantiomers and hydrophilic analytes were also satisfactorily detected and separated. This work provides a new approach for the facile synthesis of MOF-based liquid chromatographic separation material by using green deep eutectic solvent and water as the reaction media.
The rapid development of microfluidic technology has led to the evolution of microdroplets from simple emulsion structures to complex multilayered and multicompartmental configurations. These advancements have endowed microdroplets with the capability to contain multiple compartments that remain isolated from one another, enabling them to carry different molecules of interest. Consequently, researchers can now investigate intricate spatially confined chemical reactions and signal transduction pathways within subcellular organelles. Moreover, modern microdroplets often possess excellent optical transparency, allowing fluorescently labelled, multi-layered, and compartmental droplets to provide detailed insights through real-time, in situ, and dynamic fluorescence imaging. Hence, this review systematically summarizes current methodologies for preparing multicomponent microdroplets and their applications, particularly focusing on fluorescent microdroplets. Additionally, it discusses existing critical challenges and outlines future research directions. By offering a comprehensive overview of the preparation methods and applications of fluorescent microdroplets, this review aims to stimulate the interest of researchers and foster their utilization in more complex and biomimetic environments.
Photocatalytic CO2 reduction reaction (CO2RR) is one of the promising strategies for sustainably producing solar fuels. The precise identification of catalytic sites and the enhancement of photocatalytic CO2 conversion is imperative yet quite challenging. This critical review summarizes recent advances in porous photo-responsive polymers, including covalent organic frameworks (COFs), covalent triazine frameworks (CTFs), and conjugated microporous polymers (CMPs), those can be rationally designed from the molecular level for visible-light-driven photocatalytic CO2 reduction. Additionally, special emphasis is placed on how the well-defined active sites on these polymers can influence their properties and photocatalytic performance. The precise regulation and control of microenvironments and electronic properties of metal active centers are crucial for boosting catalytic efficiency and selectivity, as well as for the design of better photocatalysts for CO2 reduction.
Recently circularly polarized luminescence (CPL) materials have attracted significant interest. Introducing reversible dynamic property to these materials has been a key focus in cutting-edge fields, such as in high-level information encryption. Here, we provided a novel and general strategy involving handedness-selective filtration and ground-state chiral self-recovery (CSR) in double film system to address this issue. Based on this strategy, we achieved CPL switch through the reversible modulation of ground-state chirality including absorption and scattering circular dichroism (CD) signals over the full UV-visible wavelength range (365-700 nm) in a single azobenzene polymer (PAzo) film. More importantly, by flexibly changing the type of fluorescent films, it is convenient to achieve general excited-state CSR, that is reversible switching of full-color including ideal white (CIE coordinate (0.33, 0.33)), as well as room-temperature phosphorescent CPL. All these CPL signals without almost any intensity decay after three cycles of on-and-off switching. Experimental results indicated that the trans-cis isomerization and ordered rearrangement of azobenzene units in PAzo film were the fundamental reasons for realizing CPL switching. Finally, based on this system we achieved dynamic visual encryption and decryption process including multiple decryption methods. This study provides an effective method for constructing a universally applicable chiroptical switch in excited state.
Chloroform is a common and excellent solvent for preparing high-efficient organic solar cells (OSCs), however, it is toxic and poisonable chemical. In comparisons, deuterated chloroform (DC) is less toxic and costly, and particularly, it is non-poisonable chemical. In this paper, we use DC to replace ultra-dry chloroform (UC) as the processing solvent for preparation of active layers of organic solar cells. First, we selected PM6:BTP-eC9 as the basic binary and counted 100 solar cells' data, from which comparable device performance were obtained with use of DC and UC. Interestingly, DC showed better reproducibility, superior storage under a nitrogen atmosphere and a little better performance than UC. Both DC and UC gave rise of comparable hole and electron mobilities and similar charge recombination losses. Second, we based PM6:Y6 and D18-Cl: Y6 as the binaries and similar effects were obtained from both UC and DC when counting 30 devices for each binary. Third, the universality of the use of DC for preparing high-efficient OSCs were again checked with several binary and ternary systems. In all, this study demonstrate that DC can replace UC for use in the field of OSCs.
Metal complexes hold significant promise in tumor diagnosis and treatment. However, their potential applications in photodynamic therapy (PDT) are hindered by issues such as poor photostability, low yield of reactive oxygen species (ROS), and aggregation-induced ROS quenching. To address these challenges, we present a molecular self-assembly strategy utilizing aggregation-induced emission (AIE) conjugates for metal complexes. As a proof of concept, we synthesized a mitochondrial-targeting cyclometalated Ir(III) photosensitizer Ir-TPE. This approach significantly enhances the photodynamic effect while mitigating the dark toxicity associated with AIE groups. Ir-TPE readily self-assembles into nanoaggregates in aqueous solution, leading to a significant production of ROS upon light irradiation. Photoirradiated Ir-TPE triggers multiple modes of death by excessively accumulating ROS in the mitochondria, resulting in mitochondrial DNA damage. This damage can lead to ferroptosis and autophagy, two forms of cell death that are highly cytotoxic to cancer cells. The aggregation-enhanced photodynamic effect of Ir-TPE significantly enhances the production of ROS, leading to a more pronounced cytotoxic effect. In vitro and in vivo experiments demonstrate this aggregation-enhanced PDT approach achieves effective in situ tumor eradication. This study not only addresses the limitations of metal complexes in terms of low ROS production due to aggregation but also highlights the potential of this strategy for enhancing ROS production in PDT.
Surface with well-defined components and structures possesses unique electronic, magnetic, optical and chemical properties. As a result, surface chemistry research plays a crucial role in various fields such as catalysis, energy, materials, quantum, and microelectronics. Surface science mainly investigates the correspondence between surface property and functionality. Scanning probe microscopy (SPM) techniques are important tools to characterize surface properties because of the capability of atomic-scale imaging, spectroscopy and manipulation at the single-atom level. In this review, we summarize recent advances in surface electronic, magnetic and optical properties characterized mainly by SPM-based methods. We focus on elucidating the π-magnetism in graphene-based nanostructures, construction of spin qubits on surfaces, topology properties of surface organic structures, STM-based light emission, tip-enhanced Raman spectroscopy and integration of machine learning in SPM studies.
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