Latest ArticlesThere is a great demand for high-performance hydrogen sulfide (H2S) sensors with low operating temperatures. Ag/In2O3 hexagonal tubes with different proportions were prepared by the calcination of Ag+-impregnated indium-organic frameworks (CPP-3(In)), and the developed sensors exhibit enhanced gas-sensing performance toward H2S. Gas sensing measurements indicate that the response of Ag/In2O3 (2.5 wt%) sensor to 5 ppm H2S has the highest response (119), operated at 70 ℃. The Ag/In2O3 (2.5 wt%) based sensor exhibits short response time (20 s), low detection limit (300 ppb), and good selectivity toward H2S gas, which imply that the CPP-3(In)-derived Ag/In2O3 hexagonal tube is a promising candidate to be constructed a low power-consumption H2S sensor.
A novel ZnII-based metal-organic framework with the formula of {[Zn2(BBIP)2(NDC)2]·H2O}n (JXUST-5) derived from 3, 5-bis(benzimidazol-1-yl)pyridine (BBIP) and 1, 4-naphthalenedicarboxylic acid (H2NDC) has been synthesized. The adjacent ZnII ions are linked through two BBIP ligands to form a [Zn2(BBIP)2] secondary building unit (SBU). The neighbouring SBUs are further connected by NDC2− with μ2-η1: η1 and μ2-η1: η1: η1 bridging modes to form a two-dimensional (2D) framework. Topological analysis shows that JXUST-5 could be simplified as an uninodal fes topology with a point symbol of {4.82}. Furthermore, the 2D framework net could be extended through C-H···π interaction to form the three-dimensional supramolecular structure. Luminescent experiments suggest that JXUST-5 could selectively and sensitively recognize Al3+ and Ga3+ through fluorescence enhancement effect along with a relatively large red shift. The detection limits for Al3+ and Ga3+ are 0.17 and 0.69 ppm, respectively. Interestingly, the sensing process for both Al3+ and Ga3+ could be directly observed with naked eyes under 365 nm UV lamp. Notably, JXUST-5 could be recycled at least five times as a fluorescent sensor toward Al3+ and Ga3+, which is the second example of turn-on MOF based fluorescent sensor toward Ga3+.
Two amphiphilic TPE E/Z isomers with aggregation induced emission (AIE) property have been synthesized and characterized. The logarithmic fluorescent intensity of the two molecules was in positive relationship with logarithmic viscosity of liquid. To note, the Z-TPE isomer exhibited more sensitivity in the viscosity of liquid sensing in comparison with the corresponding E-TPE counterpart (around 1.80 folds). Furthermore, two molecules could be used as fluorescent sensors for mechanical properties (viscosity and storage modulus) of hydrogel as well. In addition, two sensors displayed low cytotoxicity in normal tissue cell line (L929) within the concentration range of 2-10 μmol/L. These results potentially promised their applications as fluorescent sensors for mechanical properties in the fields of biological and biomedical.
Thiolate-bridged hetero-bimetallic complexes [Cp*M(MeCN)N2S2FeCl][PF6] (2, M = Ru; 3, M = Co, Cp* = η5-C5Me5, N2S2 = N, N'-dimethyl-3, 6-diazanonane-1, 8-dithiolate) were prepared by self-assembly of dimer [N2S2Fe]2 with mononuclear precursor [Cp*Ru(MeCN)3][PF6] or [Cp*Co(MeCN)3][PF6]2 in the presence of CHCl3 as a chloride donor. Complexes 2 and 3 exhibit obviously different redox behaviors investigated by cyclic voltammetry and spin density distributions supported by DFT calculations. Notably, iron-cobalt complex 3 possesses versatile reactivities that cannot be achieved for complex 2. In the presence of CoCp2, complex 3 can undergo one-electron reduction to generate a stable formally CoIIFeII complex [Cp*CoN2S2FeCl] (4). Besides, the terminal chloride on the iron center in 3 can be removed by dehalogenation agent AgPF6 or exchanged with azide to afford the corresponding complexes [Cp*Co(MeCN)N2S2Fe(MeCN)][PF6]2 (5) and [Cp*Co(MeCN)N2S2Fe(N3)][PF6] (6). In addition, complexes 2, 3 and 4 show distinct catalytic reactivity toward the disproportionation of hydrazine into ammonia. These results may be helpful to understand the vital role of the heterometal in some catalytic transformations promoted by heteromultinuclear complexes.
Semiconductor-noble metal composite has become a research focus due to its superior performance compared with its respectⅳe component. Although various methods have been developed to synthesize semiconductor-noble metal heterostructures, most of them are relatⅳely complex multistep and use toxic reactants of high cost and risk. In this work, a series of Cu2O/Ag heterojunctions were quickly prepared in one step via simple microwave-assisted green route. XRD, SEM, TEM, EDS, XPS, etc. were used to characterize obtained products, and the results indicate a Cu2O/Ag metal-semiconductor heterojunction in micro-nano size was fabricated successfully. In addition, antibacterial behavior of Cu2O/Ag heterojunctions against E. coli and S. aureus were investigated. Owing to the synergistic effect of Cu2O and Ag, the heterojunction exhibits much better antibacterial performance than the pristine Cu2O does. This work provides new insights into the green design and fabrication of surface-modified Cu2O hybrid multifunctional materials for antibacterial applications.
Acenapththylene-imide (AnI), similar to naphthalene diimide (NDI), is an outstanding building block for organic functional materials and has gained a lot of research attention. Herein, Sulphur and Selenium-embedded AnI-containing polycyclic aromatic hydrocarbon molecules, AnI-SQ and AnI-SeQ, with [1, 2, 5]thiadiazolo [3, 4-g]quinoxaline (SQ) and [1, 2, 5]selenadiazolo [3, 4-g]quinoxaline (SeQ) are designed and synthesized with low-lying LUMO energy levels. The absorption and emission of AnI-SQ and AnI-SeQ displayed a bathochromic shift upon protonation of the C = N bond. Besides, theoretical calculation indicates remarkable rigid planar backbones for both AnI-SQ and AnI-SeQ. Through self-assembly with polymeric Pluronic® F-127, corresponding hydrophilic nanoparticles (NPs) were prepared with low cytotoxicity. And AnI-SQ NPs could be applied for in vitro two-photon fluorescence imaging.
White-light-emitting diodes (WLEDs) possess many merits, such as high efficiency and stability. Developing cost-effective, environmentally friendly, high-performance luminophores to achieve high-quality, full-spectrum, white lighting is of great importance to the construction and progress of WLEDs. In this work, solid-state, highly luminescent orange-emitting nanoclusters (MgCl2-Lys-Ag/Au NCs) were prepared via the salt-induced precipitation of Lys-Ag/Au NCs from solution, which showed a high absolute quantum yield of 44.5%. A cyan-emitting metal-organic framework (MOF)-like nanomaterial (named Fe@TAOH) was also prepared by the self-assembly of the coordination compound of Fe3+ and TAOH acted upon by H3PO4 via H-bonding and π-π stacking interactions, which showed an emission peak at 485 nm and an absolute quantum yield of 21.7%. The potential application of the two facile-synthesis, low toxicity, and highly luminescent materials in WLEDs was investigated. The WLEDs was constructed by coating powdered Fe@TAOH and MgCl2-Lys-Ag/Au NCs samples on commercial GaN LED chip with 365 nm emissions, and it exhibited acceptable white light characteristics with a CIE color coordinates and a color rendering index (CRI) of (0.28, 0.34) and 79.6, respectively, implying good prospects in the field of WLEDs.
Photothermal therapy (PTT)-induced immune response has attracted much attention, however, which cannot work at full capacity. In this study, the simvastatin (SV) adjuvant is loaded into gold nanocages (AuNCs) to develop a simple drug delivery system, which can efficiently utilize the tumor-associated antigens (TAAs) for improving immune responses. AuNCs/SV-mediated PTT treatment enhances tumor cells damage and promotes the release of TAAs which are immediately captured by AuNCs/SV to form AuNCs/SV/TAAs recombinant nanoparticle. Impressively, AuNCs/SV/TAAs can accumulate in lymph nodes effectively due to the suitable size of ~55 nm and hyperthermia-induced vasodilative effect. And the co-delivery of antigen and adjuvant is beneficial to stimulating the maturation of dendritic cells for further activating T cells. In a word, the recombinant strategy could make full use of TAAs to produce an individual powerful immunotherapy.
Catalytic hydrodeoxygenation (HDO) is one of the most effective methods to upgrade the oxygen-containing compounds derived from coal tar to valuable hydrocarbons. Herein, an efficient bimetallic catalyst Pt1Ni4/MgO was prepared and applied in the HDO of dibenzofuran (DBF). High yield (95%) of the desired product bicyclohexane (BCH) was achieved at 240 ℃ and 1.2 MPa of H2. Superior catalytic performance could be ascribed to the "relay catalysis" of Pt sites and Ni sites, and the reaction pathway is proposed as well. Scale-up experiment and recyclability test were also performed, which demonstrated the recyclability and promising potential application of Pt1Ni4/MgO.
Star-shaped small molecules have attracted great attention for organic solar cells (OSCs) because they have three-dimensional charge-transport characteristics, strong light absorption capacities and easily tunable energy levels. Herein, three- and four-armed star-shaped small molecule donors, namely BDT-3Th and BDT-4Th, respectively, have been successfully designed and synthesized, which used benzodithiophene (BDT) as the central unit. The two star-shaped intermediates (2a and 2b) could be simultaneously obtained by one-step of Suzuki coupling, and 1, 2-dimethoxyethane played a key role in the Suzuki coupling. Both of them have excellent thermal stability, good solubility and broad absorption. Four-armed BDT-4Th shows a slightly higher extinction coefficient, a deeper HOMO energy level and an obviously better phase separation morphology when blended with Y6 than three-armed BDT-3Th. As a result, increased power conversion efficiency (PCE) of 5.83% is obtained in the BDT-4Th: Y6-based OSC devices, which is obviously higher than that of the BDT-3Th: Y6-based devices (PCE = 3.78%). To the best of our knowledge, this is the highest PCE among the BDT-based star-shaped donors-based OSCs. This result provides an effective strategy to obtain star-shaped small molecule donor materials for high efficient organic solar cells.