Switching between classical/nonclassical crystallization pathways of TS-1 zeolite: implication on titanium distribution and catalysis.

In the MFI zeolite crystallization process, the classical crystallization mechanism based upon the addition of silica species is often concomitant with the nonclassical route that is characteristic of the attachment of silica nanoparticle precursors. However, the factors that govern the preferences for each mechanism remain unclear. In this work, we present the impact of switching between these two crystallization pathways on the active sites and the resulting catalytic performance of the titanosilicate TS-1 zeolite.

A two-dimensional BeAu monolayer with planar hexacoordinate s-block metal atoms: a superconducting global minimum Dirac material with two perfect Dirac node-loops.

Using a starlike BeAu cluster as a building block and following the bottom-up strategy, an intriguing two-dimensional (2D) binary s-block metal BeAu monolayer with a 6/ space group was theoretically designed. Both the BeAu cluster and the 2D monolayer are global minima featuring rule-breaking planar hexacoordinate motifs (anti-van't Hoff/Le Bel arrangement), and their high stabilities are attributed to good electron delocalization and electronic-stabilization-induced steric force. Strikingly, the BeAu monolayer is a rare Dirac material with two perfect Dirac node-loops in the band structure and is a phonon-mediated superconductor with a critical temperature of 4.

A theoretical roadmap for the best oxygen reduction activity in two-dimensional transition metal tellurides.

Developing highly active and cost-effective electrocatalysts to replace Pt-based catalysts for the sluggish oxygen reduction reaction (ORR) is a major challenge in the commercialization of fuel cells. Although two-dimensional (2D) transition-metal tellurides have recently been proposed as alternative low-cost ORR catalysts, a fundamental study on the origin of the activity is required to further optimize their composition and performance. Herein, we investigated the electronic properties and ORR catalytic performances of a series of exfoliable 2D transition-metal tellurides to uncover the underlying mechanisms by means of density functional theory simulations.

Combination of vancomycin and guanidinium-functionalized helical polymers for synergistic antibacterial activity and biofilm ablation.

The emergence of various resistant bacteria and overuse of antibiotics have led to severe side effects. Therefore, developing efficient and safe antibacterial systems is important. Herein, well-defined antimicrobial material-helical poly(phenyl guanidinium isocyanide) block copolymers with different conformations (l-P3-van, d-P3-van, and dl-P3-van) that connect vancomycin (van) to the polymer through a disulfide bond were synthesized.

Construction of OH-functionalized MWCNT/solid waste composites with tubular/spherical heterostructures for enhanced electromagnetic wave absorption property.

Electromagnetic wave (EMW) absorption materials with high efficiency and simple preparation process are highly desirable for practical applications. However, there are still many obstacles to simultaneously satisfy the practical requirements. Herein, fly ash cenospheres (FACs), solid waste from power plants, were selected as a framework to prepare OH-functionalized multi-walled carbon nanotube (MWCNT)/FAC hybrids with multilayer, connected and porous architectures a facile physical mixing process for the first time.

Critical biodegradation process of a widely used surfactant in the water environment: dodecyl benzene sulfonate (DBS).

Sodium dodecyl benzene sulfonate (DBS) is a widely used surfactant that is now found extensively in water bodies because of anthropogenic emissions. Since the degradation of DBS in the environment mainly relies on microorganisms, it is essential to study the mechanism by which DBS is biodegraded. In this study, was used to research the biodegradation process of DBS.

Welding partially reduced graphene oxides by MOFs into micro-mesoporous hybrids for high-performance oil absorption.

Partially reduced graphene oxides (PRGOs) with a small number of COOH groups remaining at the edges were interlocked by UiO-66-NH nanoparticles into hierarchical porous hybrids (PRGO@UiO-66-NH) during the synthesis of UiO-66-NH in the presence of PRGOs, in which the UiO-66-NH nanoparticles provide micropores and the interlocked PRGO skeletons provide mesopores. The peak intensity of the functional groups on the PRGO@UiO-66-NH hybrids decrease greatly when compared with the GO@UiO-66-NH hybrids and the UiO-66-NH nanoparticles, and the number of -COOH at the edge of the PRGOs are approximately 6.3% after reduction, which is confirmed by the FT-IR and XPS results.

Molecular free energy optimization on a computational graph.

Free energy is arguably the most important property of molecular systems. Despite great progress in both its efficient estimation by scoring functions/potentials and more rigorous computation based on extensive sampling, we remain far from accurately predicting and manipulating biomolecular structures and their interactions. There are fundamental limitations, including accuracy of interaction description and difficulty of sampling in high dimensional space, to be tackled.

High coercivity PrFeB magnetic nanoparticles by a mechanochemical method.

NdFeB nanoparticles are widely used because of their outstanding hard magnetic properties. In fact, PrFeB has higher magneto-crystalline anisotropy than NdFeB, which makes Pr-Fe-B a promising magnetic material. However, the chemical synthesis route to PrFeB nanoparticles is challenging because of the higher reduction potential of Pr, as well as the complex annealing conditions.

A novel hydrophilic fluorescent probe for Cu detection and imaging in HeLa cells.

Copper is an essential element in living systems and plays an important role in human physiology; therefore, methods to detect the concentration of copper ions in living organisms are important. Herein, we report a highly water-soluble naphthalimide-based fluorescent probe that can be used for the detection of Cu. The probe, BNQ, has high selectivity and sensitivity.

Predissociation resonances and accurate calculations of dication HF.

It is very interesting and challenging to investigate the electronic structures of diatomic dications, due to the nature of coulombic repulsive and bound attractive dissociation limits and their avoided diabatic interactions. Using the multi-reference configuration interaction approach, comprehensive calculations of the first 36 electronic states, corresponding to 15 dissociation limits, of dication HF are reported. Good agreements for the vertical excitation energies and dissociation limits are achieved with the available references.

Materials by design at high pressures.

Pressure, a fundamental thermodynamic variable, can generate two essential effects on materials. First, pressure can create new high-pressure phases modification of the potential energy surface. Second, pressure can produce new compounds with unconventional stoichiometries modification of the compositional landscape.

Converting molecular luminescence to ultralong room-temperature phosphorescence the excited state modulation of sulfone-containing heteroaromatics.

Manipulating the molecular orbital properties of excited states and the subsequent relaxation processes can greatly alter the emission behaviors of luminophores. Herein we report a vivid example of this, with luminescence conversion from thermally activated delayed fluorescence (TADF) to ultralong room-temperature phosphorescence (URTP) a facile substituent effect on a rigid benzothiazino phenothiazine tetraoxide (BTPO) core. Pristine BTPO with multiple heteroatoms shows obvious intramolecular charge transfer (ICT) excited states with small exchange energy, featuring TADF.

Self-trapped exciton emission and piezochromism in conventional 3D lead bromide perovskite nanocrystals under high pressure.

Developing single-component materials with bright-white emission is required for energy-saving applications. Self-trapped exciton (STE) emission is regarded as a robust way to generate intrinsic white light in halide perovskites. However, STE emission usually occurs in low-dimensional perovskites whereby a lower level of structural connectivity reduces the conductivity.

Phase-Change-Memory Process at the Limit: A Proposal for Utilizing Monolayer SbTe.

One central task of developing nonvolatile phase change memory (PCM) is to improve its scalability for high-density data integration. In this work, by first-principles molecular dynamics, to date the thinnest PCM material possible (0.8 nm), namely, a monolayer SbTe, is proposed.

The inorganic cation-tailored "trapdoor" effect of silicoaluminophosphate zeolite for highly selective CO separation.

Functional nanoporous materials are widely explored for CO separation, in particular, small-pore aluminosilicate zeolites having a "trapdoor" effect. Such an effect allows the specific adsorbate to push away the sited cations inside the window followed by exclusive admission to the zeolite pores, which is more advantageous for highly selective CO separation. Herein, we demonstrated that the protonated organic structure-directing agent in the small-pore silicoaluminophosphate (SAPO) zeolite can be directly exchanged with Na, K, or Cs and that the Na form of SAPO- exhibited unprecedented separation for CO/CH, superior to all of the nanoporous materials reported to date.

Jahn-Teller Distortion Induced Mn-Rich Cathode Enables Optimal Flexible Aqueous High-Voltage Zn-Mn Batteries.

Although one of the most promising aqueous batteries, all Zn-Mn systems suffer from Zn dendrites and the low-capacity Mn/Mn process (readily leading to the occurrence of Jahn-Teller distortion, which in turn causes structural collapse and voltage/capacity fading). Here, the Mn reconstruction and disproportionation are exploited to prepare the stable, Mn-rich manganese oxides on carbon-cloth (CMOs) in a discharged state through an inverted design, which promotes reversible Mn/Mn kinetics and mitigates oxygen-related redox activity. Such a 1.

Inorganic nanocrystal-dynamic porous polymer assemblies with effective energy transfer for sensitive diagnosis of urine copper.

Despite their remarkable mechanical, optical, and electrical properties, inorganic particles and dynamic polymer assemblies encounter difficulties in their compatibility with regards to structural order and complexity. Here, covalent organic frameworks (COFs) constructed through reversible coupling reactions were exploited as dynamic porous polymers to prepare inorganic nanocrystal-polymer assemblies. Under an growth process, carbon quantum dots (CDs) were gradually prepared in the COF cavity, with a narrow size distribution (2 ± 0.

Reductive radical-initiated 1,2-C migration assisted by an azidyl group.

We report here a novel reductive radical-polar crossover reaction that is a reductive radical-initiated 1,2-C migration of 2-azido allyl alcohols enabled by an azidyl group. The reaction tolerates diverse migrating groups, such as alkyl, alkenyl, and aryl groups, allowing access to +1 ring expansion of small to large rings. The possibility of directly using propargyl alcohols in one-pot is also described.

Titanosilicate zeolite precursors for highly efficient oxidation reactions.

Titanosilicate zeolites are catalysts of interest in the field of fine chemicals. However, the generation and accessibility of active sites in titanosilicate materials for catalyzing reactions with large molecules is still a challenge. Herein, we prepared titanosilicate zeolite precursors with open zeolitic structures, tunable pore sizes, and controllable Si/Ti ratios through a hydrothermal crystallization strategy by using quaternary ammonium templates.

Thermally treated zeolitic imidazolate framework-8 (ZIF-8) for visible light photocatalytic degradation of gaseous formaldehyde.

The development of wide-spectrum responsive photocatalysts for efficient formaldehyde (HCHO) removal is highly desired yet remains a great challenge. Here we successfully converted zeolitic imidazolate framework-8 (ZIF-8), one of the most well-studied metal-organic frameworks (MOFs), from routine ultraviolet-driven to novel broad-spectrum-driven photocatalyst a facile thermal treatment. The isocyanate groups (-N[double bond, length as m-dash]C[double bond, length as m-dash]O) formed in the thermally treated ZIF-8 (ZIF-8-T) is crucial in enabling the superior photocatalytic performance in formaldehyde degradation.

Planar tetracoordinate fluorine atoms.

Among the list of planar tetracoordinate atoms, fluorine is missing. So far, there are no theoretical or experimental reports suggesting their existence. Herein, we introduce the first six combinations (FIn , FTl , FGaIn , FInTl , FInTl, and FInTl ) whose global minima contain a planar tetracoordinate fluorine.

New-phase retention in colloidal core/shell nanocrystals pressure-modulated phase engineering.

Core/shell nanocrystals (NCs) integrate collaborative functionalization that would trigger advanced properties, such as high energy conversion efficiency, nonblinking emission, and spin-orbit coupling. Such prospects are highly correlated with the crystal structure of individual constituents. However, it is challenging to achieve novel phases in core/shell NCs, generally non-existing in bulk counterparts.

Lead-Free Halide Perovskites for Light Emission: Recent Advances and Perspectives.

Lead-based halide perovskites have received great attention in light-emitting applications due to their excellent properties, including high photoluminescence quantum yield (PLQY), tunable emission wavelength, and facile solution preparation. In spite of excellent characteristics, the presence of toxic element lead directly obstructs their further commercial development. Hence, exploiting lead-free halide perovskite materials with superior properties is urgent and necessary.