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A practical catalyst-free decarboxylative radical nitrosation reaction of β-keto acids with tert-butyl nitrite in water was developed. The strategy involving radicals worked well under relatively mild conditions. This protocol presented an efficient route for the construction of various aromatic and aliphatic α-oximino ketones with different electronic and steric properties in good to excellent yields (up to 95%). [ABSTRACT FROM AUTHOR]

Lipopolysaccharides (LPS), known as endotoxins, can cause a strong inflammatory response and lead to multiple organ failure in severe cases. This work reports a simple label-free voltammetric aptasensor for highly sensitive determination of LPS using a polyethyleneimine (PEI) functionalized reduced graphene oxide (rGO) and molybdenum disulfide (MoS2) composite (PEI-rGO-MoS2) as a new nanocarrier for electroactive toluidine blue (TB). The PEI-rGO-MoS2 nanocomposite with high electrical conductivity and large specific surface area can greatly increase the loading of TB and facilitate electron transfer from TB to an electrode. Then gold nanoparticles (AuNPs) were utilized to immobilize a thiolated LPS binding aptamer (LBA), which not only exhibited excellent biocompatibility, but also significantly amplified the electrochemical signal of TB. The proposed aptasensor exhibited high sensitivity for LPS and showed a wide linear range from 5.0 × 10−5 ng mL−1 to 2.0 × 102 ng mL−1 with a low limit of detection (LOD) of 3.01 × 10−5 ng mL−1, which overcame the shortcomings of traditional detection methods and achieved fast and accurate detection of LPS. Moreover, it exhibited excellent recovery and specificity upon spiking LPS in serum samples, indicating that this method has promising application in the field of trace analysis of LPS in clinical detection. [ABSTRACT FROM AUTHOR]

Lithium metal-based batteries offer promising prospects as alternatives to today's lithium-ion batteries, due to their ultra-high energy density. Unfortunately, the application of lithium metal is full of challenges and has puzzled researchers for more than 40 years. In this feature article, we describe the history of the development of lithium metal batteries and their existing key challenges, which include non-uniform electrodeposition, volume expansion, high reactivity of the lithium metal/unstable solid electrolyte interphase (SEI), and the shuttling of active cathode materials. Then, we focus on the growth mechanisms of uneven lithium electrodeposition and extend the discussion to the approaches to inhibit lithium dendrites. Finally, we discuss future directions that are expected to drive progress in the development of lithium metal batteries. [ABSTRACT FROM AUTHOR]

A novel membrane with heterogeneously functionalized nanocrystal layers was designed to synchronously perform in situ blood separation and sensing for the extraction of pure serum without any blood cells and fibrinogen by size sieving, and simultaneously realizing the electrochemical analysis of various physiological indexes. [ABSTRACT FROM AUTHOR]

We demonstrate a facile hydrothermal method for growth of ultrathin NiCo2S4 nanosheets on reduced graphene oxide (RGO), which exhibit remarkable electrochemical performance with higher capacitance and longer cycle life than the bare NiCo2S4 hollow spheres (HSs). [ABSTRACT FROM AUTHOR]

A Schiff base N′-(3-ethoxy-2-hydroxybenzylidene)-4,5-dihydronaphtho[1,2-b]thiophene-2-carbohydrazide (LB2) was designed and synthesized based on 4,5-dihydronaphtho[1,2-b]thiophene-2-carbohydrazide and 3-ethoxy-2-hydroxybenzaldehyde, and could be used as a sensor to identify In3+ and Fe3+ through fluorescence 'off–on–off' behavior. The probe LB2 showed high sensitivity and selectivity towards In3+ and Fe3+ in the presence of other metal ions with detection limits of 8.05 × 10−9 M and 2.59 × 10−8 M, respectively. The structure of LB2 was characterized by 1H NMR, 13C NMR, FTIR and mass spectrometry. The complexation ratio of LB2 to In3+ and Fe3+ was 1 : 1 for both which was verified by mass spectrometry and the Job plot. The binding mode and sensing mechanism of LB2 with In3+ and Fe3+ were also verified. [ABSTRACT FROM AUTHOR]

A new fluorescence probe, (E)-N′-(2-hydroxybenzylidene)-6-phenylimidazo[2,1-b]thiazole-3-carbohydrazide (LB1), based on 6-phenylimidazo[2,1-b]thiazole and salicylaldehyde was designed and synthesized. The chemical structures of LB1 and its intermediate were characterized via1H NMR, 13C NMR, FTIR, and mass spectrometry. The LB1 probe exhibited high sensitivity and selectivity towards In3+ and Cr3+via a fluorescence 'off–on–off' response. The detection limits of In3+ and Cr3+ were 2.59 × 10−9 M and 8.05 × 10−7 M, respectively. The LB1 probe demonstrated ideal selectivity for In3+ among other competing ions and the newly formed complex [LB1 + In3+] could be further used as a new fluorescence platform towards Cr3+. The Job Plot of LB1 towards In3+ and Cr3+ was 1 : 1 and this was supported by mass spectrometry. The plausible binding modes and mechanisms were determined through DFT/TDDFT calculations using Gaussian 09. [ABSTRACT FROM AUTHOR]

Herein, we present a facile plasma-induced strategy to introduce plentiful oxygen vacancies in porous metal–organic framework nanosheet arrays (Ov-Fe MOF/IF). The pore structure and coordinatively unsaturated metal sites endow the Ov-Fe MOF/IF with more active sites and accelerated reaction kinetics, thereby exhibiting a low potential of 1.51 V at 10 mA cm−2 for water splitting, which outperforms most MOF-based electrocatalysts. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) flower-like Ag/ZnO heterostructures with different Ag content were prepared using a facile two-step method. The samples structure, morphology and optical properties were well-characterized using XRD, SEM, EDS, XPS, DRS, PL and ICP-AES techniques. The results demonstrated the successful deposition of Ag nanoparticles on a flower-like ZnO surface. The photocatalytic performance was evaluated by the photocatalytic degradation of rhodamine B (RhB) under ultraviolet and visible light. The results showed that the Ag/ZnO heterostructures had superior photocatalytic activity compared to the pure ZnO samples and the commercial photocatalyst TiO2 (Degussa, P25). The enhanced photocatalytic activity was attributed to the effective separation of electron/hole pairs on flower-like ZnO by employing Ag nanoparticles as a conductor. Furthermore, 3D flower-like Ag/ZnO microspheres exhibited good recycling stabilities over several separation cycles photodegradation. [ABSTRACT FROM AUTHOR]

White light-emitting NaGdF4 phosphor samples based on efficient energy transfer between Tb3+ and Eu3+ were synthesized via a conventional hydrothermal reaction process. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra and lifetime measurement were performed to characterize the samples. The energy transfer process between Tb3+ and Eu3+ was demonstrated to be a resonant type via a dipole–dipole interaction mechanism. Furthermore, for NaGdF4:Tb3+,Eu3+, white light emission can be realized in the single-phase NaGdF4 host by reasonably adjusting the relative doping concentrations of Tb3+ and Eu3+ under ultraviolet excitation. Due to their excellent PL properties and good CIE chromaticity coordinates, the as-prepared Tb3+, Eu3+ co-doped NaGdF4 nanocrystalline phosphors have potential application in field-emitting displays. [ABSTRACT FROM AUTHOR]

A series of undoped and Eu3+ doped YOF and Y1−xGdxOF (x = 0–0.7) crystals were prepared via a urea based homogeneous precipitation method followed by a heat treatment process. After Gd3+ doping, we observed the crystal phase transition, morphology transformation, and greatly enhanced luminescence properties of the YOF crystals. The results reveal that the addition of Gd3+ can promote the phase transition from the hexagonal phase to the rhombohedral phase and the morphology transformation from spheres, though a mixture of rods and spheres, to spheres. The luminescence properties of Eu3+ doped YOF phosphors were investigated upon UV excitation and the quenching concentration of Eu3+ was found to be 10 mol%. More importantly, the luminescence intensity after doping a certain amount of Gd3+ increased by 31 times compared to that of the Gd3+ free sample, which may be due to the modification of the crystal field and the crystal phase of YOF, providing an effective way to gain numerous Gd3+ doped luminescent materials. These results show that the Gd3+ doped red phosphors have potential applications in white light emitting diodes. [ABSTRACT FROM AUTHOR]

Here we report a novel pre-shell–post-core method for the fabrication of monodispersed magnetic rattle-type silica (MRS) through an entrapment process, which could be used as a promising theranostic agent for simultaneous magnetic resonance imaging and drug delivery. [ABSTRACT FROM AUTHOR]

Herein, novel and durable single-layer carbon-coated FeCo alloy nanoparticles embedded in single-walled carbon nanotubes (FeCo/SWCNTs) are rationally synthesized using a facile one-step route by aerosol-assisted floating catalyst chemical vapor deposition (CCVD). The as-synthesized unique FeCo/SWCNT catalyst exhibits remarkable oxygen electrocatalysis performance, especially oxygen evolution reaction activity and superior stability owing to the efficient synergistic effect between FeCo alloy and single-layer carbon regarding the electronic interaction and surface protection, achieving an overpotential (η) of 253 mV at 10 mA cm−2 and a Tafel slope of 44 mV dec−1 in 1.0 M KOH solution while presenting outstanding stability after being tested for 50 hours. Such high oxygen electrocatalysis performance advances realistic renewable zinc–air batteries with high efficiency as well. [ABSTRACT FROM AUTHOR]

Amorphous bimetallic coordination polymers have been prepared by a mild room temperature solution phase method and utilized as an OER electrocatalyst. Their excellent performance with an overpotential of 228 mV at 10 mA cm−2 and a Tafel slope of 30.3 mV dec−1 exhibits their great potential in the field of the OER. [ABSTRACT FROM AUTHOR]

A feasible and rapid one-step strategy has been developed to fabricate 2D metal–organic framework nanosheet (MOF-NS)@fiber composites at room temperature by spray technique, through which five kinds of MOF-NS@fiber were successfully prepared. The representative nanoscale CuBDC were synthesized on the surface of carbon fibers with homogeneous dispersion and high coverage. [ABSTRACT FROM AUTHOR]

TiO2/TiN core/shell NBs are successfully synthesized, and used as highly efficient photocatalytic H2 evolution catalysts (120 μmol h−1 g−1) from methanol solution. The TiN shell plays dual roles by extending the light absorption range and also promoting the separation/transfer of photoexcited charge carriers as an electron collector. [ABSTRACT FROM AUTHOR]

TiO2 is one of the most extensively investigated materials owing to its unique properties and several promising applications. The properties of TiO2 are highly dependent on its microstructure and feature size. Herein, we report a strategy for the synthesis of hierarchical porous TiO2 with two distinguishable scales of ligament sizes, which consists of both macro-pores and meso-pores. A metallic melt dealloying process with CuTi alloy was followed to form a porous Ti precursor. Subsequently, this precursor was used as a substrate for anodization to form TiO2. By controlling the anodization potential, time and initial porous Ti ligament size, nanotubular nanotubes or nanoporous TiO2 were distributed uniformly on the ligaments of porous Ti. Both the sizes of the macropore (400 nm to 2 μm) and mesopore (10 to 30 nm) can be tuned. A core–shell structured TiO2/Ti composite with a nanoporous or nanotubular structure in the shell and un-anodized porous Ti in the core can be achieved by partial anodization. The hierarchical structure with high surface area is essential for mass transport (large pore) and functionality (small pore), which makes it a potential candidate for various applications such as in sensors and catalysts. [ABSTRACT FROM AUTHOR]

Nanostructured TiO2 materials with a controlled morphology and structure have drawn considerable attention to both fundamental research and practical applications owing to their unique characteristics. Herein, a novel, facile, and one-step hydrothermal approach was developed to synthesize urchin-like anatase TiO2 hierarchical nanostructures assembled from ultrathin nanobelts using urea as the morphology-directing agent. The effects of the urea concentration in the preparation process were discussed intensively. Photocatalytic experiments showed that the urchin-like anatase TiO2 nanostructures possessed a much higher degradation rate of methyl orange and phenol than the most successful commercial semiconductor photocatalyst P25. The reasons for the highly efficient photocatalytic activity was ascribed to the high specific surface area (171 m2 g−1) and ultrathin 1D nanobelts of anatase TiO2 self-assembled into the urchin-like hollow spheres. The urchin-like anatase TiO2 nanostructures as photocatalysts have potential applications in environmental and energy fields for photocatalytic degradation, hydrogen production, Li-ion batteries, and dye-sensitized solar cells. In addition, new hydrothermal method can be developed for synthesis of other hierarchical nanostructures. [ABSTRACT FROM AUTHOR]

Tissue regeneration, energy conversion & storage, and water treatment are some of the most critical challenges facing humanity in the 21st century. In order to address such challenges, one-dimensional (1D) materials are projected to play a key role in developing emerging solutions for the increasingly complex problems. Eletrospinning technology has been demonstrated to be a simple, versatile, and cost-effective method in fabricating a rich variety of materials with 1D nanostructures. These include polymers, composites, and inorganic materials with unique chemical and physical properties. In this tutorial review, we first give a brief introduction to electrospun materials with a special emphasis on the design, fabrication, and modification of 1D functional materials. Adopting the perspective of chemists and materials scientists, we then focus on the recent significant progress made in the domains of tissue regeneration (e.g., skin, nerve, heart and bone) and conversion & storage of clean energy (e.g., solar cells, fuel cells, batteries, and supercapacitors), where nanofibres have been used as active nanomaterials. Furthermore, this review's scope also includes the advances in the use of electrospun materials for the removal of heavy metal ions, organic pollutants, gas and bacteria in water treatment applications. Finally a conclusion and perspective is provided, in which we discuss the remaining challenges for 1D electrospun nanomaterials in tissue regeneration, energy conversion & storage, and water treatment. [ABSTRACT FROM AUTHOR]

Mesoporous silica nanoparticles (MSNs) have attracted great attention in various biomedical applications. However, a detailed mechanism of intracellular behavior, such as reactive oxygen species (ROS), induced by MSNs, has been still paid little consideration to date. In this study, we first found that MSNs with different aspect ratios (1, 2, and 4) could decrease the intracellular ROS level in serum-free media, whereas the introduction of serum proteins could upregulate and display shape-dependent behavior. The ROS regulation mechanism by particle shapes in A375 cells was then analyzed by examining the endocytosis amount of MSNs, the mitochondrial damage, and the ROS-scavenging ability. These results indicated that the particle shapes play significant roles in regulating endogenous ROS. We envisage that the complete oxidative stress study of different shaped MSNs would provide important guidelines when considering the overall toxicity of these nanocarriers in biomedical applications. [ABSTRACT FROM AUTHOR]