A series of FFK tripeptides capped with phenylacetic acid of various fluoro-substitutions at N-terminus have been synthesized and examined for the self-assembly in aqueous conditions. The material property of FFK tripeptides dramatically changes from precipitate to hydrogel phase upon increasing the number of fluorine atoms. Peptides linked with benzyl (B-FFK) or monofluoro-benzyl (MFB-FFK) groups rapidly form solid precipitates at physiological pH conditions. Trifluoro-decorated compound (TFB-FFK) self-assembled into a metastable hydrogel which slowly transformed into a solid precipitate upon standing. A stable hydrogel formation was noticed as in the case of pentafluorobenzyl-diphenylalanyllysine (PFB-FFK) compound. TEM analysis indicates that PFB-FFK peptide assembled into twisted nanofibril structures which is predominantly stabilized by strong quadrupole π-stacking interactions and electrostatic interactions of amino acid side chain. Further, the combination of PFB-FFK and PFB-FFD peptides were also investigated for hydrogelation and the self-assembly of such systems resulted in the formation of untwisted 1D nanofibrils structures. The supramolecular coassembled hydrogels of variable stiffness have also been achieved by modulating the concentration of the peptide components which was evident from the rheological analysis. Such low molecular weight (LMW) peptides materials with tuneable mechanical properties might be a potential material for a wide range of applications in nanotechnology and biotechnology.

Covalent organic frameworks (COFs) are new generation of porous materials constructed from light elements (such as carbon, oxygen and nitrogen) linked via covalent bonds. Herein, one-pot synthesis of the composite of a COF and two-dimensional (2D) nanomaterials (graphene oxide (GO), graphitic carbon nitride (g-C3N4), and boron nitride (BN)) was reported. Melamine is poly-condensed with terephthaldehyde in the presence of GO, g-C3N4, and BN leading to the formation of a series of highly cross-linked microporous hierarchical porous amine networks. The thermal behavior, surface morphology, and crystalline structure were studied using thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The prepared COF nanocomposites possessed a high surface area of 42-509 m2 g−1 with a hierarchical porous structure and high thermal stability. COF nanocomposites (COF@GO, COF@g-C3N4, and COF@BN) were explored as an adsorbent for dye removal anionic dyes (Eosin dye and fluorescein) and cationic dyes (Fuchsine, and methylene blue). The composite materials exhibit high adsorption efficiency of 100% with excellent selectivity compared to the pristine COF. The synergic effect of COF and 2D nanomaterials improves the adsorption performance of the materials.

Covalent organic frameworks (COFs) are new generation of porous materials constructed from light elements (such as carbon, oxygen and nitrogen) linked via covalent bonds. Herein, one-pot synthesis of the composite of a COF and two-dimensional (2D) nanomaterials (graphene oxide (GO), graphitic carbon nitride (g-C3N4), and boron nitride (BN)) was reported. Melamine is poly-condensed with terephthaldehyde in the presence of GO, g-C3N4, and BN leading to the formation of a series of highly cross-linked microporous hierarchical porous amine networks. The thermal behavior, surface morphology, and crystalline structure were studied using thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The prepared COF nanocomposites possessed a high surface area of 42-509 m2 g−1 with a hierarchical porous structure and high thermal stability. COF nanocomposites (COF@GO, COF@g-C3N4, and COF@BN) were explored as an adsorbent for dye removal anionic dyes (Eosin dye and fluorescein) and cationic dyes (Fuchsine, and methylene blue). The composite materials exhibit high adsorption efficiency of 100% with excellent selectivity compared to the pristine COF. The synergic effect of COF and 2D nanomaterials improves the adsorption performance of the materials.

Alcohol dehydrogenation to carbonyl compounds and hydrogen (H2) gas offers a green and sustainable method for producing H2 and the synthesis of various pharmaceuticals and fine chemicals. However, it is a challenge to acquire remarkable selectivity toward carbonyl products. Herein, [email protected] catalyst displays high dehydrogenation over dehydration reaction for isopropanol. [email protected] core–shell was synthesized from the carbonization of metal–organic frameworks (MOFs) via a single step without the need for incorporating an external source of carbon. [email protected] showed high selectivity (100%) and increased conversion (100%) of isopropanol to acetone and hydrogen via dehydrogenation. It exhibited high stability under the reactant flow for a long time and reusability for several cycles. A mechanism of the dehydrogenation was also highlighted using different analytical methods, including X-ray diffraction (XRD), electron diffraction (ED), Fourier transform infrared (FT-IR), and high-resolution transmission electron microscopy (HR-TEM).

Alcohol dehydrogenation to carbonyl compounds and hydrogen (H2) gas offers a green and sustainable method for producing H2 and the synthesis of various pharmaceuticals and fine chemicals. However, it is a challenge to acquire remarkable selectivity toward carbonyl products. Herein, [email protected] catalyst displays high dehydrogenation over dehydration reaction for isopropanol. [email protected] core–shell was synthesized from the carbonization of metal–organic frameworks (MOFs) via a single step without the need for incorporating an external source of carbon. [email protected] showed high selectivity (100%) and increased conversion (100%) of isopropanol to acetone and hydrogen via dehydrogenation. It exhibited high stability under the reactant flow for a long time and reusability for several cycles. A mechanism of the dehydrogenation was also highlighted using different analytical methods, including X-ray diffraction (XRD), electron diffraction (ED), Fourier transform infrared (FT-IR), and high-resolution transmission electron microscopy (HR-TEM).

Alcohol dehydrogenation to carbonyl compounds and hydrogen (H2) gas offers a green and sustainable method for producing H2 and the synthesis of various pharmaceuticals and fine chemicals. However, it is a challenge to acquire remarkable selectivity toward carbonyl products. Herein, [email protected] catalyst displays high dehydrogenation over dehydration reaction for isopropanol. [email protected] core–shell was synthesized from the carbonization of metal–organic frameworks (MOFs) via a single step without the need for incorporating an external source of carbon. [email protected] showed high selectivity (100%) and increased conversion (100%) of isopropanol to acetone and hydrogen via dehydrogenation. It exhibited high stability under the reactant flow for a long time and reusability for several cycles. A mechanism of the dehydrogenation was also highlighted using different analytical methods, including X-ray diffraction (XRD), electron diffraction (ED), Fourier transform infrared (FT-IR), and high-resolution transmission electron microscopy (HR-TEM).

Hydrogen is a promising alternative energy source to conventional fuels, including fossil fuel. Thus, several methods were reported for the generation of hydrogen. This review provided a comprehensive bibliometric analysis of the publications that focus on the hydrolysis or hydrolytic dehydrogenation of sodium borohydride (NaBH4). Surveying articles in the literature showed a promising future for this technology, although some challenges lie ahead. The process can be reversible via the regeneration of the reaction by-product (NaBO2•2H2O or NaBO2•4H2O). The key parameters affecting the hydrolysis reaction of aqueous NaBH4 were also summarized. The analysis of the publications indicated that hydrogen production techniques need further investigations to be competitive and for renaissance of the current applications. This review also presented concerns behind the commercialization of the generation of hydrogen gas using the hydrolysis of NaBH4. Several materials have been reported for hydrogen generation, but thus far, no single material can simultaneously meet all the required criteria for mobile applications. Researchers and political decision-makers should manage the progress and open new channels for commercialization purposes. The hydrolysis of NaBH4 is promising for several applications, including material science, environmental fields, and energy-based applications.

Ceboruco volcano is one of the largest volcanoes of the Trans-Mexican Volcanic Belt (TMVB), which extends along central Mexico. Among the western TMVB, Ceboruco Volcano comes in the second place after Colima Volcano in its activity. Also, it is considered as the only one that has historically-documented eruptions. Few geophysical studies have been published with the aim of studying the internal structure of the volcano. In the current work, and throughout the support of the CeMIEGeo-P24 geothermal exploration project, we aim to delineate the possible subsurface structural trends, to determine the approximate depth to the basement surface, and to provide an illustrative 3D model for its subsurface structure.

To achieve such goals, a detailed analysis of the aeromagnetic data for the volcano area was performed. 2D interpretation was carried out for the aeromagnetic data. Edge detection filters, such as Tilt Derivative, and Analytic Signal, were used to map the contact/faults within the study area. In addition, 3D inversion was used to image the subsurface structure of the volcano. Aeromagnetic data was inverted using the GMSYS-3D inversion program by applying Parker algorithm. Four subsurface layers at depths of 250, 500, 750 and 1000 m were assumed during the inversion process. Results indicate that the limits “boundary” of the subsurface magma chamber of the volcano can be traced easily from the first subsurface layer. A secondary structure line appears towards the east from the volcano boundary and it can be observed from the inversion of the second and third layers. This indicates that both, the base of the volcano and the structure line, stem from the same source. Finally, they disappear in the inversion results for the last layer, which concludes that we reach the basement above which the volcano is formed. Combination of all obtained results with the geological information, helped to understand the main structure of the Ceboruco volcano.

The discovery of crown ethers and their unique interactions with ions make them to play a key role in supramolecular chemistry. In this study, we have developed a new type of amphiphilic crown ether (DB18C6, DB24C8)–conjugated phenylalanine dipeptides for the gelation of water at physiological pH. We report here for the first time that the size of the crown ether controlled the morphology of the self-assembled nanostructures of the hydrogels, as well as their interactions with human mesenchymal stem cells (hMSCs; 3A6-RFP) and mouse fibroblasts (L929). For example, relative to its D-form and other crown sizes, DB18C6LFLF exhibited greater cell adhesion and was nontoxic towards hMSCs after culturing for 72h. We hypothesize that the steric effect of the crown ether moiety in the assemblies has substantial influences on the morphology of nanostructures and cell-material response. Such distinct cell responses should be beneficial for the development of supramolecular biomaterials.

Given the photocatalytic properties of semiconducting polymers and carbon quantum dots (CQDs), we report a new structure for a metal-free photocatalytic system with a promising efficiency for hydrogen production through the combination of an organic semiconducting polymer (PFTBTA) and N-doped carbon quantum dots (NCQDs) covered by PS-PEGCOOH to produce heterostructured photocatalysts in the form of polymer dots (Pdots). This design could provide strong interactions between the two materials owing to the space confinement effect in nanometer-sized Pdots. Small particle size NCQDs are easy to insert inside the Pdot, which leads to an increase in the stability of the Pdot structure and enhances the hydrogen evolution rate by approximately 5-fold over that of pure PFTBTA Pdots. The photophysics and the mechanism behind the catalytic activity of our design are investigated by transient absorption measurement, demonstrating the role of NCQDs to enhance the charge separation and the photocatalytic efficiency of the PFTBTA Pdot.