Chemistry - An Asian Journal最新文献

One of the most promising approaches in solving the energy crisis and reducing atmospheric CO2 emissions is artificial photosynthetic CO2 reduction. The electrochemical method for CO2 reduction is more appealing since it can be operated under ambient conditions, and the product selectivity strongly depends on the applied potential. Perovskites with ferroelectric properties strongly adsorb linear CO2 molecules. In this study, barium titanate (BaTiO3) perovskite is used as an electrocatalyst to promote CO2 activation and conversion to CO. Perovskite catalysts were prepared by ball-milling followed by annealing at 900 °C for 4 to 6 h in an open atmosphere. The TEM and SEM study shows that the particle size varies in the range of 80-200 nm. Mixed phases of BaTiO3 and BaTi5O11 supported on nitrogen-doped carbon nanotubes are found to be highly active for electrocatalytic CO2 reduction to CO with maximum Faradaic efficiency of 89.4% at -1.0 V versus Ag/AgCl in CO2 saturated 0.5 KOH solution. This study concludes that mixed phases of BaTiO3 and BaTi5O11 are more active and highly selective for CO2 conversion to CO compared to single-phase BaTiO3.

This review highlights important research on anion coordination chemistry for materials applications over the last decade. This field has numerous applications in various areas, such as the environment, industry, and medicine. Despite its enormous potential, real-world applicability is still pending. However, there has been a new trajectory in the field recently, with rapid advancement in designing sophisticated molecular systems for various materials applications. To keep track of this dynamic advancement, we have discussed some outstanding research work with enormous potential for materials applications in the near future.

Tuning the electronic structure of catalysts is an efficient approach to optimize the catalytic performance of CO2 electroreduction. Herein, we constructed an efficient catalyst consisted of amorphous InOX with cottonlike structure spreading on N doped carbon (N-C) substrate to extend the catalysts-substrate interfaces for enhancing electron-transfer effect. The amorphous InOX growing on N-C substrate (InOX/N-C) exhibited an improved current density of -34.4 mA cm-2. Notably, a faradaic efficiency for formate (HCOO-) over the amorphous InOX/N-C reached 79.6% at -1.0 V versus reversible hydrogen electrode, 1.8 times as high as that (44.2%) over the amorphous InOX growing on carbon black substrate. Mechanistic studies revealed that the introduction of N-C as substrates accelerated charge-transfer process on the catalytic surface of InOX/N-C. Density functional theory calculations further revealed that the interactions between N-C substrate and InOX not only facilitated the potential-determining *HCOO protonation, but also inhabited hydrogen evolution, thus improving the catalytic performance for the production of HCOO-.

A π-extended cyclobutenofullerene containing an N,N-dimethylanilinoethynyl group was synthesized via a one-pot cascade reaction of C60 with the corresponding propargylic phosphate. The cyclobutenofullerene was further modified using either one-pot or sequential post-functionalization methods, yielding derivatives containing altered addend structures. During one-pot post-functionalization, hydration reaction of the alkyne moiety continued after the formation of cyclobutenofullerenes. The sequential post-functionalization approach involved introducing the tetracyanobutadiene structure through formal [2 + 2] cycloaddition and a subsequent retroelectrocyclization reaction with tetracyanoethylene. The electronic and optical properties of the derivatives in solution, as well as their field-effect transistor behavior in thin films, were thoroughly assessed to elucidate the optoelectronic differences arising from various addend structures. The properties of the three characteristic cyclobutenofullerene derivatives in the solution and thin films significantly varied depending on the addends. Among the three derivatives studied, only cyclobutenofullerene, featuring a folded structure induced by the hydration of the alkyne moiety, exhibited n-type semiconductor behavior in the thin films. The findings of this study present a novel methodology for synthesizing and functionalizing fullerene derivatives, together with a conceptual framework for tailoring molecular properties.

The documented work highlighted the synthesis of bis(benzotriazol-1-yl) methane derivatives using silicomolybdic acid (SMA) and successfully implemented in the stereoselective synthesis of diverse pyrrolo[3,4-b]pyridin-5-one and pyridyl isoindolinones derivatives in one-pot. The pyridinamide precursor with diverse alkynes furnished Z-selectivity of pyrrolo[3,4-b]pyridin-5-one across exocyclic C=C bond while the various benzamides on treating with 2-ethynyl pyridine afforded (E)-pyridylisoindoline-1-ones as a major isomer. The single-crystal X-ray diffraction provides strong evidence in favor of the existence and orientation of developed compounds. The broad substrate scope, easy accessibility of substrates, high stereoselectivity, scale-up synthesis, and crystal evidence demonstrate the merits of the current decorum.

The application of seawater splitting is crucial for hydrogen production; therefore, efficient electrocatalysts are necessary to prevent chlorine evolution and severe corrosion. A synergistic method is employed on CoFe LDH by integrating a conductive Ti3C2Tx MXene layer and subsequently applying anionic modulation. Robust metal-substrate interaction along with subsequent phosphidation facilitates efficient electron transfer and optimises the electronic structure of Co and Fe sites. The CoFe-P-1000@Ti3C2Tx/CC demonstrates commendable electrochemical performance, requiring overpotentials of 106.6 mV and 276 mV for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA cm-2 in 1M KOH electrolyte, while 292 mV is necessary for OER in a simulated seawater electrolyte (1 M KOH + 0.5 M NaCl). Furthermore, the CoFe-P-1000@Ti3C2Tx/CC exhibits an encouraging cell voltage of 1.59 V (j = 10 mA cm-2) for comprehensive alkaline seawater splitting, maintaining exceptional stability for over 50 hours.

The alarming increase in atmospheric CO2 levels, driven by fossil fuel combustion and industrial processes, is a major contributor to climate change. Effective technologies for selective CO2 removal are urgently needed, especially for industrial gas streams like flue gas and biogas, which contain impurities such as N2 and CH4. In this study, we designed and synthesized molecularly imprinted polymers (MIPs) using 4-vinylpyridine(4VP) and methacrylic acid(MAA) as functional monomers, and thiophene(Th) and formaldehyde(HC) as molecular templates. The MIPs were engineered to create selective molecular cavities within a nanoporous polymer matrix for efficient CO2 capture. By adjusting the molar ratios of the template to the functional monomers, we optimized the imprinting process to enhance CO2 selectivity over N2&CH4. The resulting MIPs exhibited excellent performance, achieving a maximum CO2/N2 selectivity of 153 at 25 bar and CO2/CH4 selectivity of 25.3 at 1 bar, significantly surpassing previously reported porous polymers and metal-organic frameworks(MOFs) under similar conditions. Heat of adsorption studies confirmed the strong and selective interaction of CO2 with the imprinted cavities, demonstrating the superior adsorption properties of the synthesized MIPs. This study highlights the potential of molecular imprinting for improving CO2 capture capacity and selectivity, offering a scalable solution for industrial CO2 separation.

Injectable hydrogels are a sub-type of hydrogels which can be delivered into the host in a minimally invasive manner. They can act as carriers to encapsulate and deliver cells, drugs or active biomolecules across several disease conditions. Polymers, either synthetic or natural, or even a combination of the two, can be used to create injectable hydrogels. Clinically approved injectable hydrogels are being used as dressings for burn wounds, bone and cartilage reconstruction. Injectable hydrogels have recently gained tremendous attention for their delivery into the liver in pre-clinical models. However, their efficacy in clinical studies remains yet to be established. In this article, we describe principles for the design of these injectable hydrogels, delivery strategies and their potential applications in facilitating liver regeneration and ameliorating injury. We also discuss the several constraints related to translation of these hydrogels into clinical settings for liver diseases and deliberate some potential solutions to combat these challenges.

Nickel-rich cobalt-free LiNi0.9Mn0.05Al0.05O2 (NMA955) is considered a promising cathode material to address the scarcity and soaring cost of cobalt. Particle size and elemental composition significantly impact the electrochemical performance of NMA955 cathodes. However, differences in precipitation rates among metal ions coveys a challenge in obtaining cathode materials with the desired particle size and composition via hydroxide co-precipitation synthesis. Utilizing complexing agents like ammonia offers an effective strategy to tackle these issues. Here, we investigate the optimal ammonia concentration to achieve moderate particle size and precise material composition. Although ammonia only forms complex coordination with transition metals, its concentration also affects the final product's precipitation and composition, including aluminum. This study shows that ammonia serves a dual function in NMA synthesis via hydroxide co-precipitation, i.e., regulating particle size and adjusting elemental composition. It was found that an ammonia concentration of 1.2 M achieved optimal particle size and composition, resulting in superior electrochemical performance. NMA955 synthesized in 1.2 M ammonia demonstrated a high specific capacity of 188.12 mAh g-1 at 0.1C, retained 71.16% of its capacity after 200 cycles at 0.2C, and delivered 110.30 mAh g-1 at 5C. These results suggest tuning ammonia concentration is crucial for producing high-performance cathode materials.

In this study, we focus on the designability and controllability of the interaction interface between secondary structures, and discover an important interface interaction between helical secondary structures by non-covalent synthesis along the helical axis. The formation of discrete heterochiral dimers consisting of left-handed helix and right-handed helix not only helps to discover nonclassical supramolecular chirality phenomena, but also enables controllable protein assembly. Highly ordered nanostructures were thus constructed using p-stacking dimerization of helical foldamers to control tetrameric avidin proteins. The designable and modifiable primitives of artificial folded molecules enable the modification of secondary structure interfaces through non-covalent interactions, leading to the generation of unique structures and functions. These findings are of fundamental importance to the understanding of the precise assembly process of helical foldamers and can provide insights to facilitate the rational design of abiotic protein-like tertiary structures and further functionalization.