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Developing higher-energy-density and long-lifetime lithium-based batteries is essential for rapid energy delivery and recharging in emerging electric vehicles and grid energy-storage technologies. Anode-free lithium metal batteries (LMBs) possess an advanced cell configuration with only a bare anode metal foil current collector and no other negative electrode material that can maximize the energy density at the battery-pack level. However, capacity fading and operational safety risks caused by the formation of lithium (Li) dendrites impede the practical application of anode-free LMBs. Herein, we evaluated the growth of Li dendrites on an iron (Fe) substrate surface by performing a series of systematic molecular dynamics (MD) simulations based on the embedded-atom method (EAM) force field to investigate the effects of multiple surface morphologies on the Li atomic deposition and Li dendrite self-healing processes. The kinetics of Li dendrite growth on the atomic scale demonstrate that selecting the Fe(111) surface lattice orientation, reducing undesirable surface cracks, and controlling the surface nanogroove structures can be applied to effectively prevent the formation of irreversible Li dendrites on the surface of the Fe collector, resulting in better battery cell cycling. This work indicates that understanding the mechanism of Li growth on metal surfaces to search for an anode current collector that can significantly improve cell cycling stability is crucial for developing new anode-free LMBs. [ABSTRACT FROM AUTHOR]

Herein, a 7.35 wt% Co loading C-SAC is synthesized by pyrolysis of Co-MOF-74 in a strongly polar molten salt system. In dye-sensitized solar cells, this SAC based counter electrode shows higher photoelectric conversion efficiency than the Pt counter electrode. This work provides new insights for the preparation and application of C-SACs. [ABSTRACT FROM AUTHOR]

The direct ordering of amorphous or disordered nanoparticles without high-temperature post-annealing is of great significance for their controllable synthesis and improvement of their properties; however, it remains challenging. In this work, the effects of substrate bias voltage (BV) on the direct crystallization ordering and magnetic properties of Sm–Co–X nanoparticles fabricated by cluster beam deposition (CBD) were explored. It was found that applying BV within ±4 kV did not affect the shape and size of the final deposited nanoparticles. As BV increased, the coercivity and remanence ratio of the Sm–Co–Ni nanoparticle films were significantly improved, which originated from the better crystallinity of the nanoparticles upon landing after applying BV. Further investigations were carried out on thick Sm–Co–Ni nanoparticle films with various thicknesses at a fixed BV of +1 kV. Appreciable coercivity of 6.1 kOe at room temperature was achieved for appropriate thickness without thermal annealing. The composition and structure of the Sm–Co–Ni nanoparticles were characterized by transmission electron microscopy (TEM). It was found that all three elements were homogeneously distributed in the nanoparticles, and no surface segregation was observed. The better crystallinity of Sm–Co–Ni after applying BV was also confirmed by TEM observations. Our results demonstrate that applying high BV may serve as a novel way for ordering amorphous or disordered nanoparticles without shape and size changes without the necessity of high-temperature annealing. [ABSTRACT FROM AUTHOR]

Nanocomposite hydrogels (NC gels) consisting of an acrylamide (AM) and 2-methoxyethyl acrylate (MEA) copolymer and titania nanoparticles (TiO2 NPs) as both inorganic cross-linking agents and photo-initiators were synthesized. Especially, the formation of hydrogels can be realized under daylight without using any initiating systems or special treatments. The resultant NC gels displayed outstanding mechanical performance including high extensibility (elongation at break ＞1000%), high strength (fracture stress up to 630 kPa), high toughness (∼4.64 MJ m−3), and anti-fatigue properties due to hydrogen bonding interactions between TiO2 NPs and polymer chains. Furthermore, the hydrogels also revealed considerable mechanical strength in the swollen state because of their relatively low swelling ratios. It is hoped that this novel type of NC gels could promote current hydrogel research and broaden their practical applications. [ABSTRACT FROM AUTHOR]

We present here the structural evolution of a Prussian blue analogue CuII3[CoIII(CN)6]2 (Cu–Co PBA) controlled by sodium citrate as a function of time at room temperature. We identified the different stages of Cu–Co PBA formation and elucidated its transformation kinetics. Moreover, 3D hybrid composites of nitrogen-doped porous carbon cubes, with cobalt and copper nanoparticles embedded within the well-graphitized shells, were rationally fabricated using Cu–Co PBA as the single precursor. The resulting Cu/Co@NPCC catalysts showed superior catalytic activity in the reduction of 4-nitrophenol to 4-aminophenol. Metallic cobalt and copper cores were leached out by FeCl3 and HCl treatment to determine the catalytically active sites. Results showed that the nitrogen-doped porous carbon still exhibited excellent catalytic performance after the metallic cores were removed. Based on the experimental results, we speculate that the unique structure of metal residues encapsulated inside the graphitic carbon layers may have higher catalytic activity than the metal particles themselves. [ABSTRACT FROM AUTHOR]

A key step in the workflow of bottom-up proteomics is the proteolysis of proteins into peptides with trypsin. In addition, enzyme-catalytic 18O labeled peptides as internal standards coupled with multiple reaction monitoring mass spectrometry (MRM MS) for the absolute quantitation of the target proteome is commonly used for its convenient operation and low cost. However, long digestion and labeling times, incomplete digestion and 18O to 16O back exchange limit its application, therefore, we developed a rapid and efficient digestion method based on a high ratio of trypsin to protein. In addition, after separation of the digested samples using pipette tips packed with reversed-phase packing materials in house, the trypsin can be separated, collected and reused at least four times. Based on this approach, a novel protein quantification method using 18O-labeled QconCAT peptides as internal standards combined with MRM MS for the absolute quantitation of a target proteome is established. Experimental results showed that the novel method had high digestion and 18O labeling efficiencies, and no 18O to 16O back-exchange occurred. A linear range covering 2 orders of magnitude and a limit of quantification (LOQ) as low as 5 fmol were achieved with an RSD below 10%. Then, the quantitative method is used for the absolute quantitation of drug metabolizing enzymes in human liver microsomes. The results are in good agreement with the previously reported data, which demonstrates that the novel method can be used for absolute quantitative analyses of target proteomes in complex biological samples. [ABSTRACT FROM AUTHOR]

A mesoporous poly-melamine-formaldehyde polymer with a high surface area, good porosity and a high density of amine and triazine functional groups was investigated as a highly efficient hydrogen-bonding catalyst. This porous organic polymer was found to be highly effective in catalyzing chemoselective acetalization of aldehydes, without the consumption of any dehydrating agents. The turnover frequency of mesoporous poly-melamine-formaldehyde is hundreds of times higher than melamine monomer, and this high efficiency is due to the high density of aminal (–NH–CH2–NH–) groups and triazine rings in the polymer network, which provides an inherently powerful system with multiple hydrogen bonds. This unique characteristic imparts mesoporous poly-melamine-formaldehyde polymer with a very high activity as a heterogeneous organocatalyst. The polymer is also low cost, and easy to be synthesized and recycled. [ABSTRACT FROM AUTHOR]

Surface-enhanced infrared absorption (SEIRA) can dramatically enhance the vibrational signals of analyte molecules owing to the interaction between plasmons and molecular vibrations. It has huge potential for applications in various detection and diagnostic fields. High-aspect-ratio rod-like metal nanostructures have been the most widely studied nanomaterials for SEIRA. However, nearly all of the rod-like nanostructures reported previously are fabricated using physical methods. They suffer from damping and low areal number densities. In this work, high-aspect-ratio Au nanorods are synthesized, and Au nanonails are prepared through Au overgrowth on the as-prepared Au nanorods. The aspect ratios of the Au nanorods and nanonails can be varied in the range of ∼10 to ∼60, and their longitudinal dipolar plasmon resonance wavelengths can be correspondingly tailored from ∼1.6 to ∼8.3 μm. The Au nanonails exhibit superior SEIRA performance with 4-aminothiophenol used as the probe molecules. They are further used to detect the common biomolecule l-cysteine. Numerical simulations are further performed to understand the experimental results. They match well with the experimental observations, revealing the mechanism of the SEIRA enhancement. Our study demonstrates that colloidal high-aspect-ratio Au nanonails and nanorods can function as SEIRA nanoantennas for highly sensitive molecular detection in various situations.

Superparamagnetic Fe 3 O 4 nanoparticles were successfully deposited on the surface of MoS 2 nanosheets (Fe 3 O 4 /MoS 2 ) by a sonochemical method and the obtained Fe 3 O 4 /MoS 2 nanocomposites were used as a promising candidate for a magnetorheological (MR) fluid. This MR fluid was prepared from the Fe 3 O 4 /MoS 2 nanocomposites and its corresponding MR performances were examined using a rotational rheometer. The MR fluid based on Fe 3 O 4 /MoS 2 showed typical MR effects with increasing viscosity, shear stress, yield stress and dynamic shear modulus depending on the applied magnetic fields. Compared with commercial carbonyl iron (CI) particles, the sedimentation stability of the Fe 3 O 4 /MoS 2 -MR fluid was greatly improved because of its unique two-dimensional structure and the reduced fluid-particle density mismatch. Therefore, the prepared Fe 3 O 4 /MoS 2 -based MR fluid with typical MR effects and good sedimentation stability would have great potential in practical applications.

A key step in the workflow of bottom-up proteomics is the proteolysis of proteins into peptides with trypsin. In addition, enzyme-catalytic (18)O labeled peptides as internal standards coupled with multiple reaction monitoring mass spectrometry (MRM MS) for the absolute quantitation of the target proteome is commonly used for its convenient operation and low cost. However, long digestion and labeling times, incomplete digestion and (18)O to (16)O back exchange limit its application, therefore, we developed a rapid and efficient digestion method based on a high ratio of trypsin to protein. In addition, after separation of the digested samples using pipette tips packed with reversed-phase packing materials in house, the trypsin can be separated, collected and reused at least four times. Based on this approach, a novel protein quantification method using (18)O-labeled QconCAT peptides as internal standards combined with MRM MS for the absolute quantitation of a target proteome is established. Experimental results showed that the novel method had high digestion and (18)O labeling efficiencies, and no (18)O to (16)O back-exchange occurred. A linear range covering 2 orders of magnitude and a limit of quantification (LOQ) as low as 5 fmol were achieved with an RSD below 10%. Then, the quantitative method is used for the absolute quantitation of drug metabolizing enzymes in human liver microsomes. The results are in good agreement with the previously reported data, which demonstrates that the novel method can be used for absolute quantitative analyses of target proteomes in complex biological samples.