Tuning the Composition and Structure of Ni@MoC Nanosheets for Highly Active and Stable Electrocatalysis in Water Splitting

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Tuning the Composition and Structure of Ni@MoC Nanosheets for Highly Active and Stable Electrocatalysis in Water Splitting

A nanosheet catalyst consisting of MoC/Mo2C-coated carbon nanotubes was prepared by hydrothermal synthesis and annealing, which exhibited excellent catalytic performance and stability for electrolytic water in a two-electrode system.


Abstract

The conventional electrolytic water-splitting process for hydrogen production is plagued by high energy consumption, low efficiency, and the requirement of expensive catalysts. Therefore, finding effective, affordable, and stable catalysts to drive this reaction is urgently needed. We report a nanosheet catalyst composed of carbon nanotubes encapsulated with MoC/Mo2C, the Ni@MoC-700 nanosheet showcases low overpotentials of 275 mV for the oxygen evolution reaction and 173 mV for the hydrogen evolution reaction at a current density of 10 mA ⋅ cm−2. Particularly noteworthy is its outstanding performance in a two-electrode system, where a cell potential of merely 1.64 V is sufficient to achieve the desired current density of 10 mA ⋅ cm−2. Furthermore, the catalyst demonstrates exceptional durability, maintaining its activity over a continuous operation of 40 hours with only minimal attenuation in overpotential. These outstanding activity levels and long-term stability unequivocally highlight the promising potential of the Ni@MoC-700 catalyst for large-scale water-splitting applications.

Quasi‐Diamond Platelet‐Shaped Zinc Oxide Nanostructures Display Enhanced Antibacterial Activity

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Quasi-Diamond Platelet-Shaped Zinc Oxide Nanostructures Display Enhanced Antibacterial Activity

The quasi-diamond platelet-shaped ZnO (neZnO) nanostructures exhibited enhanced antibacterial activity against Escherichia coli (G−) and Staphylococcus aureus (G+) compared to the quasi-round particles. The morphology of the material plays an important or determining role in the antimicrobial activity, but not the enrichment of oxygen vacancies in neZnO.


Abstract

The current study compares the antibacterial activity of zinc oxide nanostructures (neZnO). For this purpose, two bacterial strains, Escherichia coli (ATCC 4157) and Staphylococcus aureus (ATCC 29213) were challenged in room light conditions with the aforementioned materials. Colloidal and hydrothermal methods were used to obtain the quasi-round and quasi-diamond platelet-shape nanostructures. Thus, the oxygen vacancy (VO) effects on the surface of neZnO are also considered to assess its effects on antibacterial activity. The neZnO characterization was achieved by X-ray diffraction (XRD), a selected area electron diffraction (SAED) and Raman spectroscopy. The microstructural effects were monitored by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, optical absorption ultraviolet visible spectrophotometry (UV-Vis) and X-ray photoelectron spectroscopy (XPS) analyses complement the physical characterization of these nanostructures; neZnO caused 50 % inhibition (IC50) at concentrations from 0.064 to 0.072 mg/mL for S. aureus and from 0.083 to 0.104 mg/mL for E. coli, indicating an increase in activity against S. aureus compared to E. coli. Consequently, quasi-diamond platelet-shaped nanostructures (average particle size of 377.6±10 nm) showed enhanced antibacterial activity compared to quasi-round agglomerated particles (average size of 442.8±12 nm), regardless of Vo presence or absence.

Mild Hydrogenation of 2‐furoic acid by Pt Nanoparticles Dispersed in Hierarchical ZSM‐5 Zeolite

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Hydrogenation of biobased compound can add value to platform molecules obtained from biomass refining. Herein, we explore the hydrogenation of 2-furancarboxylic acid (FCA), a derivative of furfural, with H2 generated in situ by NaBH4 hydrolysis at ambient conditions. Nearly complete conversion of FCA was obtained with tetrahydrofuroic acid (THFA) and 5-hydroxyvaleric acid (5-HVA) as the only two reaction products over Pt nanoparticles supported on hierarchical ZSM-5. Small Pt nanoparticles (2 to 3 nm) were stabilized by ZSM-5 nanosheets. At an optimized Pt loading, the Pt nanoparticles can catalyze the hydrolysis of NaBH4 and the subsequent hydrogenation of FCA with the assistance of Brønsted acid sites. Nanostructuring ZSM-5 into nanosheets and its acidity contributes to the stability of the dispersed Pt nanoparticles. Deactivation due to NaBO2 deposition on the Pt particles can be countered by a simple washing treatment. Overall, this approach shows the promise of mild hydrogenation of biobased feedstock coupled with NaBH4 hydrolysis.

Evaluation of the Potential Therapeutic Properties of Liquidambar orientalis Oil

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Evaluation of the Potential Therapeutic Properties of Liquidambar orientalis Oil


Abstract

Liquidambar orientalis Mill., commonly called the Anatolian sweetgum or Sigla tree, is endemic to southwestern Turkey. It has been historically significant in traditional medicine. In our research, we delved into the therapeutic attributes of its oil, emphasizing its antioxidant, antimicrobial, and antitumor properties. The primary chemical constituent of the gum is styrene, accounting for 78.5 %. The gum demonstrated antioxidant capabilities in several assays, including in 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP). It displayed bactericidal actions against various gram-positive bacteria, such as Staphylococcus aureus, and gram-negative strains, including Escherichia coli. Additionally, the oil showcased potent antitumor effects against breast (MDA-MB-231), lung (A549), and prostate (PC3) cancer cell lines. These effects were found to be both time- and dose-dependent. L. orientalis Mill. oil showed the best antitumor activity against breast, lung, and prostate cancer cell lines after the 24 h and 48 h treatment. Its oil might induce autophagy in the PC3 prostate cancer cell line, whereas its cytotoxicity against MDA-MB-231 and A549 cancer cell lines might not be correlated with autophagy or apoptosis pathways. In conclusion, the oil from the Sigla tree offers promising therapeutic potential and warrants further exploration.

Assembly of Multi‐Compartment Cell Mimics by Droplet‐Based Microfluidics

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Assembly of Multi-Compartment Cell Mimics by Droplet-Based Microfluidics

This Concept highlights and reviews the progress made in the construction of hierarchically organized cell-mimics using droplet-based microfluidics methods. By exploiting the versatility and precision of droplet-based microfluidics, it has become possible to routinely produce well-defined cell-like systems. This technology has opened the door to the development of sophisticated adaptive cell mimics and bioreactors.


Abstract

In recent years, there has been a growing interest in multi-compartment systems as a means of developing materials that mimic the structure and function of biological cells. These hierarchical systems, including artificial cells and cell-like reactors, can efficiently perform biochemical tasks by exploiting compartmentalization inspired by biological systems. However, the bottom-up design of cell mimics presents significant challenges due to the need for precise and efficient assembly of components. This short review examines recent advances in droplet-based microfluidics (DBM), which has emerged as a powerful technique for creating cell-like systems with multi-compartment architectures, precise composition, and biomimetic functionality. DBM has proven to be a reliable method for generating populations of cell-mimics with a compartment-in-compartment structure, some of which have adaptable properties that resemble the dynamic properties of natural cells. Notable examples will be discussed to illustrate how droplet-based microfluidics provides a versatile approach to create, manipulate, and study cell-mimics.

Synthesis and Properties of Boron‐Containing Heteromerous Bistricyclic Aromatic Enes: Structural Effects on Thermodynamic Stability and Photoreactivity

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Overcrowded bistricyclic aromatic enes (BAEs) have several conformations such as twisted and anti-folded conformers, and their stereochemistry and chromism have been studied in earnest. In this study, we synthesized boron-containing heteromerous BAEs having various tricyclic structures and investigated their photophysical properties. Single-crystal X-ray analysis revealed that the introduction of a rigid fluorene unit resulted in a twisted conformer, whereas the introduction of flexible units such as thioxanthene and 9,9-dimethyl-9,10-dihydroanthracene units resulted in an anti-folded conformer. The absorption spectra of the heteromerous BAEs were dependent on the introduced tricyclic structures, suggesting the immense impact of the tricyclic structures on the electronic structures of BAEs. DFT calculations revealed the large effect of the flexibility of the tricyclic structures on the thermodynamic stability of the conformers. In addition, the boron-containing heteromerous BAEs underwent photocyclization reactions, indicating their potential application as precursors of polyaromatic hydrocarbons and helical aromatic materials.