Latest ArticlesReversible boronate-catechol linkage was widely used to construct two-dimensional coatings and threedimensional nanostructures or hydrogels. The construction of these functional materials usually requires the pre-synthesis of macromolecular building blocks, and direct gelation between natural polyphenols and small molecule boronic acids is yet to be investigated. In this study, we fabricated a family of allsmall-molecule dynamic covalent gels consisting of tannic acid and boronic acids. Transparent and thixotropic gels were formed by boronate affinity towards catechol groups abundant on natural polyphenols. The gels showed multi-responsiveness, such as acid-, base-, reduction-and oxidantsensitive depending on the used boronic acid building blocks. The chemistry for gel formation and stimuli-responsiveness was characterized by 11B NMR spectroscopy. The multi-stimuli responsiveness, green processing and facile modular design make the boronic acid-tannic acid gels promising candidates for the development of smart soft materials.
In this work, ternary organic solar cells (OSCs) combining a fullerene derivative PC71BM with a nonfullerene acceptor N2200-F blended with a polymer donor PM6 were reported. Compared with the binary systems, the highest power conversion efficiency (PCE) of 8.11% was achieved in ternary solar cells with 30 wt% N2200-F content, mainly due to the improved short-circuit current density (Jsc) and fill factor (FF). Further studies showed that the improved Jsc could attribute to the complementary absorption of the two acceptors and the enhanced FF was originated from the higher hole mobility and the fine-tuned morphology in the ternary system. These results demonstrate that the combination of fullerene and nonfullerene acceptors in ternary organic solar cells is a promising approach to achieve high-performance OSCs.
A ferrocene-initiated radical reaction of benzoquinone with amines has been successfully developed for the direct access to diaminobenzoquinone imines in high yields, in which the commercially available and cheap ferrocene was employed as a radical initiator and TBHP was used as an oxidant. Moreover, this reaction could be achieved with low loading of ferrocene (0.5 mol%). This protocol is highly efficient with good substrate tolerance and provides a new approach for the construction of benzoquinone imines with potential pharmaceutical interest.
Fluorescence switch plays a vital role in bioelectronics and bioimaging. Herein, we presented a new kind of facile electrostatic complex nanoparticles (ECNs) for fluorescence switching in cells and marking of individual cell. The ECNs were prepared by mixing positively charged poly(6-(2-(thiophen-3-yl)ethoxy) hexyl trimethylammonium bromide) (PT) and negatively charged diarylethene sodium salt (DAECOONa). DAE-COONa is a photoswitchable molecule which can be transformed between the ring-closed form and ring-open form under the irradiation of UV or visible light. The closed-form of DAE-COONa can efficiently quench the fluorescence of PT through intermolecular energy transfer, while the open form of DAE-COONa does not influence the emission of PT. Thus, the fluorescence of ECNs can be modulated by light irradiation, and the ECNs with good fluorescence switching performance have been employed for fluorescence imaging and individual cell lighting up process successfully. We demonstrate that the electrostatic complex strategy provides a facile method to construct fluorescence switch for selective cell marking and imaging applications.
The discrimination against nutritional fat emulsion injections was considered by imaging tools, which aims to elucidate the in vivo behaviors of nanoemulsions. In this study, 20% nutritional fat emulsion injections were selected from different company including original and generic products. Meanwhile, a water quenching fluorescent probe (P2) was used to label them by an incubation method. The fluorescent intensity analysis of blood-borne fluorescence reveals rapid clearance of nanoemulsion in all groups, which shows 'L'-type blood kinetic profiles. However, these kinetic parameters do not have significant difference. Following intravenous administration, the nanoemulsions in all groups concomitantly accumulated in organs of reticulo-endothelial system (RES), such as liver and spleen, and were cleared from body circulation mostly after 12 h. AUC(0-t) of organs from different groups showed dissimilar results in some organs. These intuitional results are of significance in understanding the in vivo behaviors of nanoemulsions, which can provide a new way to discriminate against nutritional fat emulsions.
A nonanuclear Cu4ⅡTi5Ⅳ heterometallic cluster, [Ti5Cu4O6(ba)16] (1, Hba=benzoic acid) was synthesized in one-pot reaction under the solvothermal condition. The metallic skeleton 1 contains a Ti5 core constructed from two vertex-shared Ti3 triangles and four separated Cu atoms outside which are connected together by μ3-O2- ions. Total 16 ba- ligands adopt μ2-η1:η1 coordination mode to protect the overall heterometallic core. Due to the unique d-d transitions of CuⅡ ion, the reflectance spectrum of 1 displays broad and strong absorption towards visible light extending to the near-infrared region. Moreover, 1 shows almost purely paramagnetic behavior with the presence of weak antiferromagnetic interactions at low temperatures.
Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science. Especially, it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors. Herein, we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes (Co3O4/NCNTs) hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air. The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions. As sensor electrode, the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40 μA (mmol/L)-1 cm-2, a linear range of 5.00 μmol/L-11.00 mmol/L, and a detection limitation of 1 μmol/L in H2O2 detection, and a good glucose detection performance with 5 μmol/L. These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.
In this work, the protic ionic liquid [DBUH] [Im] (1, 8-diazabicyclo[5.4.0]-7-undeceniumimidazolide) was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl carbonate. At 70 ℃, up to 97% conversion of ethylene carbonate and 91% yield of dimethyl carbonate were obtained with 1 mol% [DBUH] [Im] (relative to ethylene carbonate) as catalyst in 2 h. Even at room temperature, the conversion of ethylene carbonate can reach 94% and the yield of dimethyl carbonate can approach 81% for 6 h. Catalytic mechanism investigation showed the high catalytic efficiency of this ionic liquid results from the synergistic activation effect, wherein the cation can activate ethylene carbonate and the anion can activate methanol through hydrogen bond formation. Although the reusability of the ionic liquid need to be further improved, high efficiency and commercial availability of [DBUH] [Im] render it a promising catalyst for the preparation of dimethyl carbonate.
Highly efficient, cost-effective, and durable electrocatalysts for hydrogen evolution reaction (HER) in water splitting is crucial for energy conversion and storage. Herein, we report NiCoP 1D nanothorn arrays grown on 3D porous Ni film current collectors (Ni/NiCoP) as the novel electrocatalytic electrodes. The 3D hierarchically porous nickel films containing large 7 ± 2 μm pores and small pores less than 1 μm are obtained through using hydrogen bubbles dynamic template method. The NiCoP 1D nanothorns are about 70 nm in diameter and 4-8 μm in length. The porous Ni/NiCoP electrocatalytic electrodes demonstrate much higher catalytic activity and remarkable stability for long-term HER. The excellent electrocatalytic performance might be attributed to the inherent nature of highly catalytic active NiCo bimetal phosphides and the unique architecture of 1D nanothorn active materials directly integrated on the 3D hierarchically porous metallic nickel conductive skeletons. The developed electrode has been fabricated to the integrated solar-driven seawater-splitting system.