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A novel Sm(III) orotate complex, [NaSm(orotate)4(H2O)10]·3H2O, has been synthesized and its structure determined by single crystal X-ray diffraction and vibrational (IR and Raman) spectroscopic methods. The title compound crystallizes in the non-centrosymmetric orthorhombic space group Cmc21 with Z = 4. In the crystal structure, one of the two independent orotate ligands links the Sm(III) and Na(I) cations, forming chains. The second orotate ligand completes the coordination environment of the Na(I) ion, resulting in layers that are parallel to the ab plane. This arrangement leads to an extensive three-dimensional network structure, characterized by numerous intermolecular O–H⋯O and N–H⋯O interactions. [ABSTRACT FROM AUTHOR]

Due to population growth and global technological development, energy consumption has increased exponentially. The global energy crisis opens up many hotly debated topics regarding energy generation and consumption. Not only is energy production in short supply due to limited energy resources but efficient and sustainable storage has become a very important goal. Currently, there are energy storage devices such as batteries, capacitors, and super-capacitors. Supercapacitors or electrochemical capacitors can be very advantageous replacements for batteries and capacitors because they can achieve higher power density and energy density characteristics. The evolution and progress of society demand the use of innovative and composite nanostructured metal oxide materials, which fulfill the requirements of high-performance technologies. This review mainly addresses the synthesis techniques and properties of 2D and 3D metal oxide nanostructured materials, especially based on Ti, Fe, Ga, and Sn ions, electrochemical methods used for the characterization and application of 2D, and 3D nanostructured metal oxide structures in electrochemical storage systems of energy. [ABSTRACT FROM AUTHOR]

Colloidal quasi-two-dimensional cadmium chalcogenide nanoplatelets have attracted considerable interest due to their narrow excitonic emission and absorption bands, making them promising candidates for advanced optical applications. In this study, the synthesis of quasi-two-dimensional CdSe NPLs with a thickness of 3.5 monolayers was investigated to understand the effects of synthesis temperature on their stoichiometry, morphology, and optical properties. The NPLs were synthesized using a colloidal method with temperatures ranging from 170 °C to 210 °C and optimized precursor ratios. Total reflection X-ray fluorescence (TXRF) analysis was employed to determine stoichiometry, while high-resolution transmission electron microscopy (HRTEM) and UV-Vis spectroscopy and photoluminescence spectroscopy were used to analyze the structural and optical characteristics. The results showed a strong correlation between increasing synthesis temperature and the enlargement of nanoscroll diameters, indicating dynamic growth. The best results in terms of uniformity, stoichiometry, and optical properties were achieved at a growth temperature of 200 °C. At this temperature, no additional optical bands associated with secondary populations or hetero-confinement were observed, indicating the high purity of the sample. Samples synthesized at lower temperatures exhibited deviations in stoichiometry and optical performance, suggesting the presence of residual organic compounds. [ABSTRACT FROM AUTHOR]

In the proposed work, a two-dimensional microcavity ring with waveguide structure is designed and simulated to sense the existence of malignant cells in the bioanalyte. Two-dimensional photonic crystal (PhC) sensor is designed and analysed using MIT MEEP tool. Rods in air structure is used to implement the proposed ring with bus waveguide structure. Five normal (INOK) cells and oral cancerous (YD-10B) cells are considered for the analysis of sensor performance. The effect of variation in the transmission spectrum is analysed for the presence of malignant cells in the test sample. The structural parameters of the design are fine-tuned to enhance the sensitivity of the sensor. The two most important parameters, Q-factor and sensitivity, are calculated from the obtained results. The highest sensitivity of 995 nm/RIU with a Q-factor of 70 is achieved. The sensor proposed in the present work will be a better candidate for highly accurate sensing devices for biomedical applications. [ABSTRACT FROM AUTHOR]

Layered 2D materials such as transition metal chalcogenides are promising electrocatalysts for hydrogen evolution reaction (HER) due to the flexible compositions and distinctive electronic structures. However, their active sites usually stem from the edges, whereas the basal planes with the higher surface area are difficult to activate for water dissociation and H2 evolution. Here, a novel quasi‐2D AgRuO3 compound, which can be readily activated by cyclic voltammetry and split into layered structures with more exposed basal planes is reported. This results in an outstanding HER activity with a low overpotential of only 37 mV at 10 mA cm−2 and a Tafel slope of 36 mV dec−1. It is found that the oxygen vacancies generated on the basal planes during activation can thermodynamically facilitate water adsorption, dissociation, and intermediate OH* desorption compared with the pristine AgRuO3, as revealed by theoretical calculations. Thus, the oxygen vacancies on the exposed basal planes are the active centers. This work sheds light on the evolution of a quasi‐2D metal oxide during HER and highlights the active role of basal planes that can facilitate water dissociation in alkaline water electrolysis. [ABSTRACT FROM AUTHOR]

Active layers of p–i–n organic–inorganic hybrid perovskite solar cells (PSCs) are passivated by star‐shape, multifunctional triazinane molecules, cyanuric acid (CA), and Tris(dibutylhydroxy‐ benzyl)isocyanuric acid (TPCA). The most interesting is that CA is used as a bulk additive is able to induce a two‐dimensional (2D) structure at grain boundaries (GBs) of the perovskite when excess PbI2 is present. TPCA is also important to use as a perovskite surface modifier and to reduce the defects in perovskite layer further. The reduced ideality factors, enhanced photoluminescence, and prolonged lifetimes all indicate suppression of non‐radiative recombination. The combination of the two substantially improves fill‐factors and open‐circuit voltages of the devices. This leads to markedly enhanced stabilities of the devices. [ABSTRACT FROM AUTHOR]

For a further understanding on 3D shock train structure and correlation between 3D and 2D shock trains at Mach 1.5 and 3.0, the SST turbulence model based on Reynolds average algorithm was employed to simulate the 3D and 2D structures of the shock trains in the isolator respectively, of which the mesh sizes were 18 million and 200 thousand, respectively. First, when the full flow state of the nozzle was completely converged, the shock train structure was induced by a linearly increasing back pressure at the outlet. Then, the 3D shock train simulation results in xy-plane and zx-plane perspectives were analyzed. Finally, structures of the 3D shock train in different slices and structures of the 2D shock train were analyzed for comparison. It is found that the shock train at Mach 1.5 is symmetrical in xy-plane and zx-plane perspectives, which is highly similar to the 2D simulation results. However, the shock train at Mach 3.0 is symmetrical in the xy-plane perspective, while it is asymmetrical in the zx-plane perspective. The asymmetrical structure is highly similar to 2D simulation results. Therefore, there is a ″quasi-2D area″ in the 3D shock train. For the shock train at Mach 1.5, the structures in the areas including the central position and a certain range on both sides of the xy-plane and zx-plane perspectives can be approximated as 2D structures (The proportion of ″quasi-2D area″ is about 40%); for the shock train at Mach 3.0, the structures in the areas including the central position and a certain range on both sides of the symmetrical viewing angle can be approximated as 2D structures (The proportion of ″quasi-2D area″ is about 60%).

Quantum-confined CdTe nanoplatelets (NPL) are synthesized in colloidal solutions. The formation, growth, and transformation of 2D NPLs are monitored using UV-visible absorption PL spectroscopy and transmission electron microscopy. The luminescence intensity of NPL dependences on the temperature and injection of precursors is shown. It is found that the luminescence spectra shift to the long-wavelength region with increasing temperature due to an increase in the thickness of the NPL. The dependence of the band gap on the thickness of the NPL is shown. The band gap is determined by the thickness and number of layers. The dependence of the concentration of precursors in the reaction mass and the kinetics of NPL growth are shown. The excitation of defect states luminescence depends on the coordinating oleic ligand. The crystal structure of the CdTe NPL was analyzed via the electron diffraction pattern (ED), which allows a comparative conclusion about the crystal structure of the obtained NPL samples. [ABSTRACT FROM AUTHOR]

In this paper, we present a study of the sub-monolayer gold intercalation of graphene on Ir(111) using scanning tunnelling microscopy (STM). We found that Au islands grow following different kinetics than growth on Ir(111) without graphene. Graphene appears to increase the mobility of Au atoms by shifting the growth kinetics of Au islands from dendritic to a more compact shape. Graphene on top of intercalated gold exhibits a moiré superstructure, with parameters significantly different from graphene on Au(111) but almost identical to graphene on Ir(111). The intercalated Au monolayer shows a quasi-herringbone reconstruction with similar structural parameters as on Au(111). [ABSTRACT FROM AUTHOR]

Electronic structures of superlattices and encapsulated layers are obtained by Green's function metho d. The simple scheme for estimation of interlayer charge transfer is proposed. As an example, layers of graphene and graphene-like compounds are considered. [ABSTRACT FROM AUTHOR]

This study presents the first investigation of BC 3 semiconductor monolayer using DFT to reveal its electronic, thermal, and optical characteristics. Phonon band structure and ab-initio molecular dynamics simulations provide evidence that BC 3 semiconductor monolayer has the characteristics of a dynamically and thermally stable structure. The electronic band structure of the BC 3 monolayer is studied, revealing a direct band gap and the electron charge distribution indicates dominant covalent bonds in the structure. Analysis of thermal properties, such as entropy, heat capacity, and thermal conductivity, at different temperatures, demonstrated that the BC 3 monolayer displays substantial lattice thermal conductivity. The optical behavior of BC 3 in reaction to infrared light is characterized by notable fluctuations in the refractive index and optical conductivity. The existence of a prominent peak with high intensity in the dielectric function indicates significant absorption in the infrared range, emphasizing the material's potential for applications in optoelectronics and energy harvesting. The results emphasize the promise of the BC 3 semiconductor monolayer as a versatile substance for cutting-edge optoelectronic applications, which will contribute to improvements in infrared technology and other related sectors. [ABSTRACT FROM AUTHOR]

The present study investigates the structural, electronic, thermal, and optical properties of a novel two-dimensional Al 2 Te 3 using GGA and HSE06 functional in the framework of density functional theory. The formation energy, the phonon dispersion, and AIMD calculations confirm the structural, dynamical, and thermal stability of Al 2 Te 3 , respectively. The electronic band structure and partial density of states indicate the semiconducting characteristics of 2D Al 2 Te 3 with band gap values of 1.92 eV (GGA) and 2.78 eV (HSE06). The thermal properties of Al 2 Te 3 reveal a high heat capacity due to a very high phonon density of states. This property signifies the material's growing ability to store thermal energy. Thus the entropy demonstrates a continuous increase with temperature, adhering to the second law of thermodynamics. The analysis of optical properties of Al 2 Te 3 demonstrates strong light interaction in the ultraviolet, UV, region, and the optical band gap is found to be larger than the electronic band gap for both GGA and HSE06 functional due to indirect behavior of the band gap. Furthermore, the static dielectric function, refractive index, and optical conductivity are found to be smaller in the case of HSE06 compared to the GGA which may be due to reduced transition probability, and less screening effects including in the HSE06 functional. These findings offer valuable insights into the potential applications of Al 2 Te 3 in various fields, including thermal energy storage and optoelectronics. • High thermal energy storage of 2D Al2Te3. • AIMD and Phonon dispersion confirm thermal and dynamic stability of Al2Te3. • HSE06 confirm better results comparing to the GGA. • Optical transitions are seen in the ranging from far visible to UV regions. [ABSTRACT FROM AUTHOR]

Catalase is a crucial enzyme in antioxidant defense systems protecting eukaryotes from oxidative stress. These proteins are present in almost all living organisms and play important roles in controlling plant responses to biotic and abiotic stresses by catalyzing the decomposition of H2O2. Despite their importance, little is known about their expression in the majority of monocotyledonous species. Here, we isolated and characterized two novel catalase genes from Triticum turgidum and Hordeum vulgare, designated as TtCAT1 and HvCAT1, respectively. Phylogenetic analysis revealed that TtCAT1 and HvCAT1 presented 492 aa and shared an important identity with other catalase proteins belonging to subfamily 1. Using bioinformatic analysis, we predicted the 3D structure models of TtCAT1 and HvCAT1. Interestingly, analysis showed that the novel catalases harbor a peroxisomal targeting signal (PTS1) located at their C-terminus portion, as shown for other catalase proteins. In addition, this motif is responsible for the in silico peroxisomal localization of both proteins. Finally, RT-qPCR analysis showed that TtCAT1 and HvCAT1 are highly expressed in leaves in normal conditions but faintly in roots. Moreover, both genes are upregulated after the application of different stresses such as salt, osmotic, cold, heavy metal, and hormonal stresses. The positive responses of TtCAT1 and HvCAT1 to the various stimuli suggested that these proteins can help to protect both species against environmental stresses. [ABSTRACT FROM AUTHOR]

Quantum-confined CdTe nanoplatelets (NPL) are synthesized in colloidal solutions. The formation, growth, and transformation of 2D NPLs are monitored using UV-visible absorption PL spectroscopy and transmission electron microscopy. The luminescence intensity of NPL dependences on the temperature and injection of precursors is shown. It is found that the luminescence spectra shift to the long-wavelength region with increasing temperature due to an increase in the thickness of the NPL. The dependence of the band gap on the thickness of the NPL is shown. The band gap is determined by the thickness and number of layers. The dependence of the concentration of precursors in the reaction mass and the kinetics of NPL growth are shown. The excitation of defect states luminescence depends on the coordinating oleic ligand. The crystal structure of the CdTe NPL was analyzed via the electron diffraction pattern (ED), which allows a comparative conclusion about the crystal structure of the obtained NPL samples.

The shortage of powerful functionalities on scalable α-zirconium phosphate (ZrP) materials blocks the facile preparation of highly dispersed and immobilized metal nanocatalysts. We herein present a mild and facile mussel-inspired strategy based on polydopamine (PDA) for the surface modification of ZrP, and hence, the generation of powerful functionalities at a high density for the straightforward reduction of chloroauric acid to Au nanoparticles (AuNPs) and the immobilization of AuNPs. The resulting ternary ZrP@PDA/Au exhibited ultra-small AuNPs with a particle size of around 6.5 nm, as estimated based on TEM images. Consequently, the ZrP@PDA/Au catalyst showed significant activity in the catalytic conversion of 4-nitrophenol (4NP) to 4-aminophenol (4AP), a critical transformation reaction in turning the hazard into valuable intermediates for drug synthesis. The PDA was demonstrated to play a critical role in the fabrication of the highly efficient ZrP@PDA/Au catalyst, far outperforming the ZrP/Au counterpart. The turnover frequency (TOF) achieved by the ZrP@PDA/Au reached as high as 38.10 min−1, much higher than some reported noble metal-based catalysts. In addition, the ZrP@PDA/Au showed high stability and reusability, of which the catalytic efficiency was not significantly degraded after prolonged storage in solution. [ABSTRACT FROM AUTHOR]

New electromagnetic microwave absorption materials not only require strong absorption capacity and wide absorption frequency but also lightweight and thin thickness. "Wide, strong, light, and thin" is the overall goal of the current research on electromagnetic microwave absorption materials. Therefore, both human survival and the need for military equipment are encouraging researchers to develop new high-performance electromagnetic microwave absorption materials. A FeCo/GO composite has been successfully fabricated by a two-step method. Various devices were applied to separately measure the structural characteristics, microscopic morphology, and properties of the composite. The results demonstrate that the electromagnetic microwave absorption of the FeCo/GO composite is excellent. At a frequency of 10.7 GHz, the maximum reflection loss (RLmax) value is − 39.2 dB, the effective bandwidth of RLmax less than − 10 dB is 3.8 GHz (8.6–12.4 GHz), and the thickness is 5.0 mm. The electromagnetic microwave absorption performance and impedance matching of the FeCo/GO composite is superior to that of single materials, which can be explained in detail by the electromagnetic microwave absorption mechanism. Thus, it can be observed that the FeCo/GO composite is a promising electromagnetic microwave absorber in future high-performance materials. [ABSTRACT FROM AUTHOR]

Catalase is a crucial enzyme in antioxidant defense systems protecting eukaryotes from oxidative stress. These proteins are present in almost all living organisms and play important roles in controlling plant responses to biotic and abiotic stresses by catalyzing the decomposition of H2O2. Despite their importance, little is known about their expression in the majority of monocotyledonous species. Here, we isolated and characterized two novel catalase genes from Triticum turgidum and Hordeum vulgare, designated as TtCAT1 and HvCAT1, respectively. Phylogenetic analysis revealed that TtCAT1 and HvCAT1 presented 492 aa and shared an important identity with other catalase proteins belonging to subfamily 1. Using bioinformatic analysis, we predicted the 3D structure models of TtCAT1 and HvCAT1. Interestingly, analysis showed that the novel catalases harbor a peroxisomal targeting signal (PTS1) located at their C-terminus portion, as shown for other catalase proteins. In addition, this motif is responsible for the in silico peroxisomal localization of both proteins. Finally, RT-qPCR analysis showed that TtCAT1 and HvCAT1 are highly expressed in leaves in normal conditions but faintly in roots. Moreover, both genes are upregulated after the application of different stresses such as salt, osmotic, cold, heavy metal, and hormonal stresses. The positive responses of TtCAT1 and HvCAT1 to the various stimuli suggested that these proteins can help to protect both species against environmental stresses.

High-entropy (HE) MXene is the current research hotspot in the field of two-dimensional (2D) MXene materials. Unlike MXene, which contains only one or rarely two transition metals, HE MXene consists of multiple transition metals, which have both the excellent chemical properties of MXene and inherit the outstanding mechanical properties of HE materials. However, the synthesis and application of HE MXene are not well summarized at present. Here, we summarize the current strategies for synthesizing HE MAX phases and HE MXene, discuss computational studies on the structure as well as function of HE MXene, and demonstrate the application of HE MXene in energy storage and other aspects. Due to its fascinating structural and functional potential and the richness of its design, HE MXene deserves further in-depth study. [Display omitted] [ABSTRACT FROM AUTHOR]

The understanding of the functional properties of mitochondrial transfer RNA (mt tRNAs) depend on the knowledge of its structure. tRNA acts as an interface between polynucleotides and polypeptides thus, they are key molecules in protein biosynthesis. The tRNA molecule has a functional design and, given its importance in the translation of mitochondrial genes, it is plausible that modifications of the structure can affect the synthesis of proteins and the functional properties of the mitochondria. In a previous work, the mitochondrial genome of an individual of the nesting Caretta caretta of the Colombian Caribbean was obtained, where specific mutations were identified in the only tRNALeu (CUN), tRNATrp and tRNALys genes. In order to analyze the effect of these mutations on these three mt tRNAs, the prediction of 2D and 3D structures was performed. Genes were sequenced in 11 nesting loggerhead turtles from the Colombian Caribbean. Two-dimensional structures were inferred using the ARWEN program, and three-dimensional structures were obtained with the RNA Composer 3D program. Two polymorphisms were identified in tRNATrp and another one was located in tRNALys, both specific to C. caretta. The thymine substitution in nucleotide position 14 of tRNATrp could constitute an endemic polymorphism of the nesting colony of the Colombian Caribbean. Two 2D and three 3D patterns were obtained for tRNATrp. In the case of tRNALys and tRNALeu 2D and 3D structures were obtained respectively, which showed compliance to canonical structures, with 4 bp in the D-arm, 4–5 bp in the T-arm, and 5 bp in the anticodon arm. Moderate deviations were found, such as a change in the number of nucleotides, elongation in loops or stems and non-Watson–Crick base pairing: adenine–adenine in stem D of tRNATrp, uracil–uracil and adenine–cytosine in the acceptor arm of the tRNALys and cytosine–cytosine in the anticodon stem of the tRNALeu. In addition, distortions or lack of typical interactions in 3D structures gave them unique characteristics. According to the size of the variable region (4–5 nt), the three analyzed tRNAs belong to class I. The interactions in the three studied tRNAs occur mainly between D loop—variable region, and between spacer bases—variable region, which classifies them as tRNA of typology II. The polymorphisms and structural changes described can, apparently, be post-transcriptionally stabilized. It will be crucial to perform studies at the population and functional levels to elucidate the synthetic pathways affected by these genes. This article analyses for the first time the 1D, 2D and 3D structures of the mitochondrial tRNALys, tRNATrp and tRNALeu in the loggerhead turtle.

The objective of this article is to study how the stator step skewing method can lead to the reduction of the cogging torque of a transverse‐flux permanent‐magnet (TFPM) machine with flux concentrators. Three structures are analysed and compared in terms of their influence of the skewed displacement on the cogging torque using the three‐dimensional finite element method (3D‐FEM). Thereafter, to validate the FEM results, cogging torque is calculated by applying a Schwarz–Christoffel (SC) conformal mapping. To apply this transformation, the 3D TFPM generator structure with axially magnetised permanent magnets (PMs) is converted into a 2D structure with radially magnetised PMs and the cogging torque of the machine is predicted using both the analytical method and 3D‐FEM. The accuracy of the approach is demonstrated by the adequate agreement between the results obtained through this SC mapping and those of the 3D‐FEM. In addition, two 100 W prototyped TFPM machines are designed, simulated, manufactured and tested to validate the effects of the step‐skewed stator yoke on the predicted cogging torque and back‐EMF. [ABSTRACT FROM AUTHOR]

The understanding of the functional properties of mitochondrial transfer RNA (mt tRNAs) depend on the knowledge of its structure. tRNA acts as an interface between polynucleotides and polypeptides thus, they are key molecules in protein biosynthesis. The tRNA molecule has a functional design and, given its importance in the translation of mitochondrial genes, it is plausible that modifications of the structure can affect the synthesis of proteins and the functional properties of the mitochondria. In a previous work, the mitochondrial genome of an individual of the nesting Caretta caretta of the Colombian Caribbean was obtained, where specific mutations were identified in the only tRNALeu (CUN), tRNATrp and tRNALys genes. In order to analyze the effect of these mutations on these three mt tRNAs, the prediction of 2D and 3D structures was performed. Genes were sequenced in 11 nesting loggerhead turtles from the Colombian Caribbean. Two-dimensional structures were inferred using the ARWEN program, and three-dimensional structures were obtained with the RNA Composer 3D program. Two polymorphisms were identified in tRNATrp and another one was located in tRNALys, both specific to C. caretta. The thymine substitution in nucleotide position 14 of tRNATrp could constitute an endemic polymorphism of the nesting colony of the Colombian Caribbean. Two 2D and three 3D patterns were obtained for tRNATrp. In the case of tRNALys and tRNALeu 2D and 3D structures were obtained respectively, which showed compliance to canonical structures, with 4 bp in the D-arm, 4-5 bp in the T-arm, and 5 bp in the anticodon arm. Moderate deviations were found, such as a change in the number of nucleotides, elongation in loops or stems and non- Watson-Crick base pairing: adenine-adenine in stem D of tRNATrp, uracil-uracil and adenine-cytosine in the acceptor arm of the tRNALys and cytosine-cytosine in the anticodon stem of the tRNALeu. In addition, distortions or lack of typical interactions in 3D structures gave them unique characteristics. According to the size of the variable region (4-5 nt), the three analyzed tRNAs belong to class I. The interactions in the three studied tRNAs occur mainly between D loop—variable region, and between spacer bases—variable region, which classifies them as tRNA of typology II. The polymorphisms and structural changes described can, apparently, be post-transcriptionally stabilized. It will be crucial to perform studies at the population and functional levels to elucidate the synthetic pathways affected by these genes. This article analyses for the first time the 1D, 2D and 3D structures of the mitochondrial tRNALys, tRNATrp and tRNALeu in the loggerhead turtle. [ABSTRACT FROM AUTHOR]

The results of a theoretical study of the piezoresistive properties of ideal silicene and germanene nanoribbons with different types of conductivity are presented. Within the framework of the Hubbard model, the band structure of the studied nanoparticles is simulated and the longitudinal component of the elastoconductivity tensor is analytically calculated, and its dependence on the relative strain of longitudinal compression and tension and the width of the nanoribbon is studied.

Abstract Stable 2D/2D reduced graphene oxide-bismuth tungstate (rGO-BWO) compounds were synthesized via a facile hydrothermal process. The synthesized rGO-BWO compounds show high photocatalytic activity on aqueous tetracycline degradation, better than that of pure 2D BWO and rGO. rGO not only acts as the acceptor, transporter, and mediator to promote the photogenerated electrons transfer, also plays an important role in the blue shift of Fermi level, leading to the more negative conduction band potential, and benefitting the generation of O 2 −. Graphical abstract Unlabelled Image Highlights • Stable 2D/2D nano-structured rGO-BWO compounds were successfully synthesized. • rGO act as the acceptor, transporter, and mediator to promote the carriers transfer. • O 2 – and holes play the main roles in the photocatalytic degradation over rGO-BWO. [ABSTRACT FROM AUTHOR]

Background Lewis’s law and Aboav-Weaire’s law are two fundamental laws used to describe the topology of two-dimensional (2D) structures; however, their theoretical bases remain unclear. Methods. We used R software with the Conicfit package to fit ellipses based on the geometric parameters of polygonal cells of ten different kinds of natural and artificial 2D structures. Results. Our results indicated that the cells could be classified as an ellipse’s inscribed polygon (EIP) and that they tended to form the ellipse’s maximal inscribed polygon (EMIP). This phenomenon was named as ellipse packing. On the basis of the number of cell edges, cell area, and semi-axes of fitted ellipses, we derived and verified new relations of Lewis’s law and Aboav-Weaire’s law. Conclusions. Ellipse packing is a short-range order that places restrictions on the cell topology and growth pattern. Lewis’s law and Aboav-Weaire’s law mainly reflect the effect of deformation from circle to ellipse on cell area and the edge number of neighboring cells, respectively. The results of this study could be used to simulate the dynamics of cell topology during growth. [ABSTRACT FROM AUTHOR]

We prepared a two-dimensional transition metal carbide Ti2CTx by treatment of Ti2AlC in molten fluoride salt. Two fluorinated salt systems were used to etch Al from Ti2AlC powder precursor under the argon atmosphere, and then the resulting MXene was delaminated with TBAOH to produce few-layered nanosheets of Ti2CTx. The reaction was undergone at different temperatures to study the effect of temperature. The results show that the optimal reaction temperature is 600 °C in LiF-NaF-KF system, and 850 °C in NaFKF system. The molten salt treated products are delaminated and quasi-2D MXene sheets can be obtained. The thickness of the MXene sheets prepared from the binary molten salt system is smaller than that of the ternary molten salt system. [ABSTRACT FROM AUTHOR]

[Display omitted] • Aurivillius-phase CaBi 2 Ta 2 O 9 nanoplates were synthesized successfully. • Abundant OVs were introduced on the surface of CaBi 2 Ta 2 O 9 nanoplates. • The extended visible light absorption range has been achieved in CaBi 2 Ta 2 O 9. • The surface OVs helps the separation of photogenerated carriers. • The optimized CBTO-OV-2 shows an excellent photocatalytic H 2 production activity. Solar-driven water splitting over semiconductor-based photocatalyst is considered as one of the most promising approaches to address the looming energy shortage and environmental pollution. However, most of photocatalysts still suffer from low hydrogen production activity owing to the poor photo-absorption ability, rapid recombination of photo-generated charge carriers and insufficient surface active sites. Herein, we tackle these challenges by introducing surface oxygen vacancies (OVs) on the layered Aurivillius-phase perovskite CaBi 2 Ta 2 O 9 nanoplates via a combined high-temperature molten salt and post-reduction process. Theoretical and experimental results demonstrate that the rich OVs anchored on the surface of CaBi 2 Ta 2 O 9 nanoplates not only extend the photo-responsive range to visible region, improve the separation efficiency of photo-induced charge carriers, but also enrich the surface reactive sites. As a result, under a 300 W xenon lamp irradiation, the OVs-abundant CaBi 2 Ta 2 O 9 nanoplates exhibit an outstanding H 2 production rate, which is 7.4 times higher than that of the bulk CaBi 2 Ta 2 O 9 in the absence of OVs. Our study provides a general and efficient coupling strategy to advance the H 2 production performance of layered perovskite oxide for solar energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tb-NB MOFs were prepared at room temperature and realized dual emission at 424 and 544 nm. • Tb-NB MOFs with 2D structure were conducive to target diffusion. • The strong binding ability between phosphate and Tb3+ interrupted the interaction between metal ions and ligands. Here, we reported a ratiometric fluorescence strategy for the detection of phosphate (Pi) in artificial wetland water. The strategy was based on dual-ligand two-dimensional terbium-organic frameworks nanosheets (2D Tb-NB MOFs). 2D Tb-NB MOFs were prepared through blending 5-boronoisophthalic acid (5-bop), 2-aminoterephthalic acid (NH 2 -BDC) and Tb3+ ions at room temperature in the presence of triethylamine (TEA). The dual-ligand strategy realized dual emission originated from ligand NH 2 -BDC and Tb3+ ions at 424 and 544 nm, respectively. Pi could compete with ligands to coordinate Tb3+ due to the strong binding ability between Pi and Tb3+, resulting in structural destruction of 2D Tb-NB MOFs, so static quenching and antenna effect between ligands and metal ions were interrupted, and emission at 424 nm was enhanced and emission at 544 nm was weakened. This novel probe had excellent linearity with Pi concentrations from 1 to 50 μmol/L; the detection limit was 0.16 μmol/L. This work revealed that mixed ligands improved sensing efficiency of MOFs by enhancing the sensitivity of the coordination between the analyte and MOFs. [ABSTRACT FROM AUTHOR]

A new coordination polymer {[Cu(dps)2(DMSO)2](ClO4)2}n has been synthesized basing on 4,4′- dipyridyl sulfide. The structure of the obtained complex has been studied by single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Single crystals of [C(NH2)3][HC(NH2)2]PbI4 (GuFAPbI4) and [HSC(NH2)2][HC(NH2)2]PbI4 (TuFAPbI4) were obtained from solutions of the binary halides in HI or DMF. Large crystals grown from HI are dark-brown while single phase powders synthesized from DMF are orange. The crystal structure of GuFAPbI4 (I2/m, Z=12, a=14.3147(2), b=12.7591(2), c=25.7377(4)Å), β=101.459(1), 4256 refl., 196 param., R1=0.024, wR2=0.061) represents a 2D perovskite with a new motif similar to Ruddlesden-Popper phases (AX)m(A′BX3)n and m=n=1. The layers are formed by corner-sharing PbI6 octahedra. According to the cut-out of the 3-D perovskite the structure of GuFAPbI4 can be assigned as a (210)-oriented representative. So one octahedron is linked in trans-position and two in cis-orientation. The structure of TuFAPbI4 (P21/n, Z=12, a=14.4208(6), b=12.7545(7), c=26.3982(11) Å), β=100.609(3)°, 6808 refl., 275 param., R1=0.048, wR2=0.096) represents a simple distortion variant of GuFAPbI4. GuFAPbI4 and TuFAPbI4 were further characterized by vibrational spectroscopy and optical spectroscopy. The optical band gap was determined as 2.34 eV in agreement to the observed color. So both compounds are not suitable as a dye in the PSC perovskite solar cell. Similar to other Pb-containing 2D perovskites there is a significant excitonic peak (2.31 eV). TuFAPbI4 represents the first example with protonated thiourea as an organic cation. Therefore, we characterized protonated thiourea iodide and introduce protonated thiourea [HSC(NH2)2]+ as a new cation for hybrid halogeno perovskites. [ABSTRACT FROM AUTHOR]

Single crystals of [C(NH2)3][HC(NH2)2]PbI4 (GuFAPbI4) and [HSC(NH2)2][HC(NH2)2]PbI4 (TuFAPbI4) were obtained from solutions of the binary halides in HI or DMF. Large crystals grown from HI are dark-brown while single phase powders synthesized from DMF are orange. The crystal structure of GuFAPbI4 (I2/m, Z=12, a=14.3147(2), b=12.7591(2), c=25.7377(4)Å), β=101.459(1), 4256 refl., 196 param., R1=0.024, wR2=0.061) represents a 2D perovskite with a new motif similar to Ruddlesden-Popper phases (AX)m(A′BX3)n and m=n=1. The layers are formed by corner-sharing PbI6 octahedra. According to the cut-out of the 3-D perovskite the structure of GuFAPbI4 can be assigned as a (210)-oriented representative. So one octahedron is linked in trans-position and two in cis-orientation. The structure of TuFAPbI4 (P21/n, Z=12, a=14.4208(6), b=12.7545(7), c=26.3982(11) Å), β=100.609(3)°, 6808 refl., 275 param., R1=0.048, wR2=0.096) represents a simple distortion variant of GuFAPbI4. GuFAPbI4 and TuFAPbI4 were further characterized by vibrational spectroscopy and optical spectroscopy. The optical band gap was determined as 2.34 eV in agreement to the observed color. So both compounds are not suitable as a dye in the PSC perovskite solar cell. Similar to other Pb-containing 2D perovskites there is a significant excitonic peak (2.31 eV). TuFAPbI4 represents the first example with protonated thiourea as an organic cation. Therefore, we characterized protonated thiourea iodide and introduce protonated thiourea [HSC(NH2)2]+ as a new cation for hybrid halogeno perovskites. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1T−Mn−VS 2 @Co 2 P@CC was synthesized by hydrothermal fallowed to CVD method. • Synergism of 1T−Mn−VS 2 and Co 2 P enhances the overall water splitting. • DFT validates defect engineering with interface modeling for fast charge transfer. • As-synthesized catalyst exhibits 98 and 250 mV for HER and OER at 10 mA cm−2. • 1T−Mn−VS 2 @Co 2 P@CC electrolyzer exhibits excellent 100 h stability at 500 mA cm−2. The rational integration of a 2D layered transition metal sulfide and phosphide in a single heterostructure can bring a breakthrough to produce hydrogen through controlled manipulation of electronic structure. Here, we report a novel design of a hierarchical 2D−2D tangled 3D heterostructure of manganese-doped 1T vanadium disulfide (1T−Mn−VS 2), assembled with cobalt phosphide (Co 2 P), at the flexible carbon cloth as 1T−Mn−VS 2 @Co 2 P@CC. The HER active 1T−Mn−VS 2 bearing catalytically active edge sites, with numbers of basal planes and OER active Co 2 P, create synergism and hastening rection kinetics towards bifunctional water splitting. The heterostructure display significantly low over potential of 98 and 250 mV for HER and OER at 10 mA cm−2. The 1T−Mn−VS 2 @Co 2 P@CC (+,-) electrochemical cell needs 1.50 V to reach a current density of 10 mAcm−2. The implication of defect engineering along with interface modeling validated by DFT study, induces the regulation of electronic structure for fast redistribution of local charges/electron transfer. [ABSTRACT FROM AUTHOR]

Fe3O4 adsorbent with 2D structures was synthesized via solvothermal method and its application in arsenic removal was investigated. Isotherms were generated at pH=4.7 and 7.6 and the results were best fitted by the Freundlich isotherm model; good As(V) adsorption capacity was achieved for the Fe3O4 adsorbent at both pH values. Furthermore, pH effects were evaluated; the optimal pH value for adsorption was 8.27 with the adsorption capacity and the removal efficiency being 18.55 mg/g and 93.69%, respectively. Based on the measurements of the zeta potential and particle size of the adsorbent, we proposed that the overall pH dependence was a result of the combined effects of the zeta potential, particle size of the adsorbent, and existing form of As(V). From kinetics studies, the As(V) adsorption by Fe3O4 adsorbent followed the pseudo-second-order model and could be described by a two stage mechanism. When initial As(V) concentration was 1 ppm, 73% of the As(V) was adsorbed within the first 2.5 minutes and an overall removal efficiency of 82.5% was achieved in 2 hours. Increased removal efficiency is expected at higher adsorbent loading, thus allowing the post-treatment water to meet drinking water quality standards. [ABSTRACT FROM AUTHOR]

Based on first-principles methods and Boltzmann transport theory, we investigated the biaxial strain effects on electronic and thermoelectric properties of three group-III nitrides (BN, AlN and GaN) 2D honeycomb mono-layered nanosheets. The direct-indirect band gap transitions occurred for BN and GaN nanosheets when the strain was applied. In addition, the band gaps decreased with increase of tensile strain; and we uncovered the mechanism behind by the total and projected density-of-state (PDOS) analyses. At the same time, we presented the contour plots of their electrical transport properties as a function of both temperature and carrier concentration at strain-free states. Power-factors of BN, AlN and GaN nanosheets were also calculated. We found only peak power factors of p-type GaN and n-type BN showed a strong dependence on biaxial strain. Such differences of the strain-dependent thermoelectric performance among BN, AlN and GaN may be due to the competition between covalency and ionicity in these 2D structures. Our results provide a new avenue to optimize thermoelectric properties of 2D nanosheets by strain engineering. [ABSTRACT FROM AUTHOR]

Two-dimensional nano metal oxides (2D-NMOs) have attracted great concerns due to high exposure of active sites and short ion transport distance. However, 2D-NMOs with the layered structure render to restack into bulk ones, resulting in the active-sites coverage and ion-transport blockage. Here, crumpled 2D NMOs with paper-ball-like shape was proposed to avoid the restacking. Our new strategy can convert diversity of metal oxide into paper-ball-like structure with controllable composition by overcoming the fragile nature of metal oxide and limitation of growth pattern. Resultantly, as-prepared 2D NMOs demonstrated superior catalytic activity and durability in both oxygen evolution reaction (OER) and organic dye degradation reaction, owing to their high exposure of active sites and low ionic diffusion resistance. [Display omitted] • More than 18 crumpled ball-like metal oxide-based catalysts enabled by aerosol synthesis, which was to assemble 2D NMOs into 3D crumpled morphology. • Ultrafine nanocrystals interconnected to form 2D nanosheets in NMOs, endowing more active sites and highly exposed surface. • The crumpled morphology demonstrated superior catalytic activity and durability in both OER and degradation. • Crumpled ball-like metal oxide-based catalysts were assembled by aerosol synthesis, which has more active sites, highly exposed surface and efficient channels. [ABSTRACT FROM AUTHOR]

Pd metallene was firstly used as cocatalysts for photocatalytic hydrogen production, greatly improving the photocatalytic performance of g-C3N4 with 2D structure. [Display omitted] • Palladium metallene (Pd-ene) was firstly used as structural matched cocatalysts for 2D photocatalysts. • The photocatalytic H 2 production rate of Pd-ene/g-C 3 N 4 was 31,292 umol/h/g, enhanced 98 times compared with g-C 3 N 4. • Pd-ene/g-C 3 N 4 outperforms Pd NC /g-C 3 N 4 loading Pd nanocluster with the same content. • A new design strategy of metallene/semiconductor photocatalysts with unique 2D-2D composite structure was proposed. Photocatalytic hydrogen production as a green and pollution-free technology plays an important role in alleviating the fossil fuel crisis, but remains a great challenge. Herein, an ultrathin two-dimensional (2D) palladium metallene (Pd-ene) is first developed as hydrogen evolution co-catalysts for g-C 3 N 4 nanosheets. The Pd-ene and Pd-ene/g-C 3 N 4 photocatalysts were fabricated by a hydrothermal method and deposition method using acetylacetonate palladium as Pd source, and the Pd-ene with a size of 100 nm uniformly distributed on the surface of g-C 3 N 4 nanosheets forming a 2D/2D structure. The Pd-ene/g-C 3 N 4 with 2 wt% Pd-ene showed the highest photocatalytic hydrogen production rate with 31,292 μmol/h/ g, which was>98 times that of the pure g-C 3 N 4 and superior to the Pd NC /g-C 3 N 4 loading with Pd nanocluster. The unique 2D/2D structure of the Pd-ene/g-C 3 N 4 catalyst, which promotes the transfer and separation of photogenerated charge carriers, is credited with the improved photocatalytic performance. In additions, the 2D structure of Pd-ene makes it expose more reaction sites for the photocatalytic reduction reaction, promoting the hydrogen production of the photocatalysts. This study demonstrates that the development of structurally matched 2D metallene co-catalysts for 2D photocatalysts is a promising strategy to obtain the photocatalysts with high hydrogen production performance. [ABSTRACT FROM AUTHOR]

SugarSketcher is an intuitive and fast JavaScript interface module for online drawing of glycan structures in the popular Symbol Nomenclature for Glycans (SNFG) notation and exporting them to various commonly used formats encoding carbohydrate sequences (e.g., GlycoCT) or quality images (e.g., svg). It does not require a backend server or any specific browser plugins and can be integrated in any web glycoinformatics project. SugarSketcher allows drawing glycans both for glycobiologists and non-expert users. The “quick mode„ allows a newcomer to build up a glycan structure having only a limited knowledge in carbohydrate chemistry. The “normal mode„ integrates advanced options which enable glycobiologists to tailor complex carbohydrate structures. The source code is freely available on GitHub and glycoinformaticians are encouraged to participate in the development process while users are invited to test a prototype available on the ExPASY web-site and send feedback.

Soil fungi are known to contain a rich variety of defense metabolites that allow them to compete with other organisms (fungi, bacteria, nematodes, and insects) and help them occupy more preferential areas at the expense of effective antagonism. These compounds possess antibiotic activity towards a wide range of other microbes, particularly fungi that belong to different taxonomical units. These compounds include peptaibols, which are non-ribosomal synthesized polypeptides containing non-standard amino acid residues (alpha-aminoisobutyric acid mandatory) and some posttranslational modifications. We isolated a novel antibiotic peptide from the culture medium of Emericellopsis alkalina, an alkalophilic strain. This peptide, called emericellipsin A, exhibited a strong antifungal effect against the yeast Candida albicans, the mold fungus Aspergillus niger, and human pathogen clinical isolates. It also exhibited antimicrobial activity against some Gram-positive and Gram-negative bacteria. Additionally, emericellipsin A showed a significant cytotoxic effect and was highly active against Hep G2 and HeLa tumor cell lines. We used NMR spectroscopy to reveal that this peptaibol is nine amino acid residues long and contains non-standard amino acids. The mode of molecular action of emericellipsin A is most likely associated with its effects on the membranes of cells. Emericellipsin A is rather short peptaibol and could be useful for the development of antifungal, antibacterial, or anti-tumor remedies.

[Display omitted] • Hydrothermally obtained PbV spherical type morphology. • 2D structure facilitate and enhances the active channel for electrolyte. • Available multiple states and active sites promotes the OER kinetics. • Excellent OER performance shown by PbV along with long stability. Lowering the overpotentials to drive the oxygen evolution reaction (OER) during the water-splitting process is the bottleneck process and holds the key to achieving cost-effective and efficient electrolysis infrastructure systems. Given this, here we report the first demonstration of utilizing a catalyst derived from lead vanadate (PVO) for alkaline electrolysis systems with record low overpotentials. The synthesis route was regulated to yield a two-dimensional (2-D) PVO structure with uniform coatings on the Ni electrode. The optimized PVO demonstrated impressively low overpotentials of 146 mV vs RHE for OER at a current density of 10 mAcm−2. The excellent OER performance was attributed to the 3D structures assembled from porous 2D PVO that promotes a facile ionic transport and accelerates electron transfer in OER electrochemical process. Importantly, the proposed approach will open a new window for possible exploitation and practical utilization of ternary vanadium oxides in alkaline electrolysis in the future. [ABSTRACT FROM AUTHOR]

Based on density functional theory electronic and magnetic structure characterizations an unusual onset of spin polarization of p states is demonstrated leading to a stable ferromagnetic order within a carbon layered honeycomb-like compound. Specifically structural relaxation of formerly studied C 2 N in 3D network and devised here in 2D layered AlB 2 -type derived structure shows that the resulting ordered compound maintains the hexagonal crystal symmetry with an exceptionally large c/a ratio leading to strong localization of N states along c and letting magnetization develop within N-p z orbitals with 1.1 μ B per formula unit. Anisotropic antibonding interactions between C and N layers allow interpreting the results. The compound is energetically characterized in ferromagnetic ground state versus less stable anti-ferromagnetic order. [ABSTRACT FROM AUTHOR]

The behavior of phenyl-C 61 -butyric acid methyl ester (PCBM) and copper-phthalocyanine (CuPc) on a Au(1 1 1) surface was investigated using scanning tunneling microscopy (STM). When CuPc was deposited in addition to PCBM it entered and disturbed the regularly spaced double row superstructure of the PCBM molecules. PCBM intermixed with CuPc to form a new square shaped superstructure that consisted of six to eight PCBM molecules with a CuPc molecule in its center. The intermixing of these materials that was observed indicated that they possessed an attractive interaction. [ABSTRACT FROM AUTHOR]

Low dimensional materials have captivated widespread attention due to their striking performances either in photocatalyst or optoelectronic areas. As motivated by this quest, we present in this work the first attempt to disclose the properties of low-dimensional Ag 2 WS 4 material. For this aim, density functional calculations were carried out. The result shows that the studied structure is mechanical, energetic, and dynamically stable. The vibrational modes were deeply discussed and assigned for the first time. Further, we show that the low dimensional Ag 2 WS 4 has a flexible structure with a wide band gap of about 1.82 eV and a dominant d orbital near the Fermi level. This trend gives the structure an interesting capability in optoelectronic and photocatalyst applications. Proof has been given by analyzing its bonding properties as well as optical ones. • For the first time, the entire set of vibrational modes is estimated and assigned. • Band gap values are in good agreement with results available. • The optical and bonding properties were calculated. • The analysis concludes that 2D-Ag 2 WS 4 is candidate for optoelectronic devises. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ultrathin Bi 2 WO 6 nanosheets with thickness 8 nm synthesised via IL-assisted route. • IL amount facilitated thickness and photoactivity control. • N at the surface beneficial for improved photocatalytic and antibacterial activity. • IL_Bi 2 WO 6 improved activity with h+ and •OH dominating role in phenol degradation. An efficient and durable utilization of light to drive photocatalytic reactions still requires the overcoming of barriers. Herein, two-dimensional (2D) ultrathin IL_Bi 2 WO 6 (IL_BWO) photocatalysts were prepared for the first time via ionic liquid-assisted hydrothermal route by adjusting the amount of tetrabutylammonium chloride [TBA][Cl], synthesis temperature and duration. IL played the role of morphology-directing agent given by selecting the amount of IL, the control of nanosheet thickness was possible. The replacement of IL with KCl resulted in the growth of similar nanostructure, but with higher thickness, while, the absence of Cl− caused the formation of clew-like microspheres. Two different model experiments, phenol degradation, and inactivation of Escherichia coli and Staphylococcus aureus bacteria were chosen to evaluate the photocatalytic activity. The improved photocatalytic performance was attributed to (i) the ultrathin structure, which let for shorter diffusion distance, (ii) the nitrogen presence in the photocatalyst structure, and (iii) the oxygen vacancies formation. The •OH and h+ were the main species involved in the mechanism of photooxidation, and could be also responsible for the enhanced antimicrobial properties. The unique strategy of IL application establishes a new insight for a controllable preparation of 2D Bi 2 WO 6 with improvement photocatalytic and antibacterial properties. [ABSTRACT FROM AUTHOR]

Mercury (Hg) pollution can negatively impact ecosystems, and there is a need for simple Hg2+ monitoring platforms. Here, a dual-ligand fluorescence probe based on terbium-organic gels (Tb-L 0.2 P 0.8 MOGs) was constructed for efficient Hg2+ detection. Tb-L 0.2 P 0.8 MOGs were developed through a facile room-temperature gelation method, showing two emission peaks derived from luminol and Tb3+ at 424 nm and 544 nm, respectively. The aggregation-induced emission (AIE) effect between luminol and Tb3+ led to luminol with blue fluorescence. However, Hg2+ could dramatically quench the fluorescence signal of luminol at 424 nm because of the intense coordination interaction of Hg2+ with luminol and photo-induced electron transfer (PET). The Phen ligand could sensitize the luminescence of Tb3+ and offer a reference fluorescence, thus resulting in a unique ratiometric fluorescence response toward Hg2+. This novel nanoprobe had excellent linearity with Hg2+ concentrations range of 0.1–30 μM; the detection limit was 3.6 nM. The analysis of real samples showed the potential application of MOGs for measuring Hg2+ in porphyra and tap water. Mixed ligands were introduced for high-efficiency strategies to improve the analytical performance by regulating the emission behavior of MOGs. [Display omitted] • Dual-ligand Tb-L 0.2 P 0.8 MOGs with 2D structure were prepared through a room-temperature gelation method. • Tb-L 0.2 P 0.8 MOGs exhibited two emission peaks deriving from luminol and Tb3+ at 424 nm and 544 nm. • AIE effect between luminol and Tb3+ made Tb-L 0.2 P 0.8 MOGs exhibit intense blue fluorescence. • The coordination of Hg2+ with luminol and PET process caused the fluorescence quenching of luminol. • Tb-L 0.2 P 0.8 MOGs showed ratiometric fluorescence response toward Hg2+ in porphyra and tap water. [ABSTRACT FROM AUTHOR]