Chemistry - An Asian Journal最新文献

This study used a one-step electrodeposition method to grow nickel molybdenum alloy catalysts (NiMo/NM) with both crystalline and amorphous states on a Ni mesh substrate. x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) jointly confirmed that the insertion of Mo atoms into the Ni lattice resulted in a heterogeneous interface with the coexistence of crystalline and amorphous states. The scanning electron microscopy (SEM) test results show that the surface of NiMo/NM alloy owns a "cauliflower-like" morphology, which increases the specific surface area of the catalyst and exposes more catalytic active sites. Under the combined action of NiMo heterogeneous interface and highly rough surface on the catalyst surface, the catalyst exhibits superior hydrogen evolution reduction (HER) catalytic activity and long-term operational stability in alkaline solutions compared to commercial catalysts Pt/C. Especially under high current densities in industrial applications and conditions simulating alkaline seawater electrolytes, NiMo/NM exhibits catalytic stability in hydrogen evolution due to the stability of its NiMo alloy structure.

Multi-stimuli responsive materials with tunable photophysical properties have applications in sensing, data security, displays, molecular actuators, soft robotics, and flexible electronics. We synthesized acylhydrazone derivatives forming crystal hydrates, cocrystal hydrates, and molecular salts that exhibit photoresponsive properties similar to single-component crystals. This represents the first study of multi-component acylhydrazone derivatives showing photoresponsive behavior, a rare phenomenon in multi-component crystals. Crystallographic, computational, and photophysical studies elucidate the structure-property relationships in substituted isonicotinohydrazide and their mechanochemically synthesized multi-component crystals.

Crystals of separate enantiomers of the [2.2]paracyclophane (pCP)-containing organoboron complexes (S_p)-1BF₂-H, (S_p)-1BF₂-iPr, and (S_p)-1BF₂-tBu were prepared. These crystals have the same space group (P2₁2₁2₁) but molecules in them participate in different intermolecular edge-to-face π-π interactions. These crystals all have fluorescence (FL) profiles consisting of two components with shorter (<10 ns) and longer (>10 ns) FL lifetimes. The former is associated with an excited monomer FL, while the latter is attributed to a "T-shaped" excimer FL, which derives from an excited dimer with a perpendicular orientation of π-planes. The "T-shaped" excimer FL was found to be promoted by intermolecular edge-to-face π-π interaction between each pCP moiety in the (S_p)-1BF₂-H crystal, which we termed pCP-to-pCP π-π interaction. Theoretical calculations suggest that a remarkable intermolecular orbital interaction occurs between HOMOs involved in the pCP-to-pCP π-π interaction. This electronic effect causes the S₀-S₁ transition dipole moment in the dimer to be larger than that in the monomer, which is suggested to be a major factor responsible for enhancing the "T-shaped" excimer FL.

The photocatalytic generation of hydrogen peroxide (H₂O₂) represents a sustainable methodology for producing this essential oxidant, potentially offering a viable alternative to the energy-intensive anthraquinone process. Among various candidates, covalent organic frameworks (COFs) have emerged as exceptional photocatalysts owing to their modularly adjustable porous structures, customizable electronic properties, and superior charge-carrier mobility. In the past years, advancements in COF-based materials have demonstrated significant progress in the photocatalytic synthesis of H₂O₂, particularly as the structural customizability of COFs provides an optimal platform for achieving high selectivity and efficiency in two-electron oxygen reduction reactions (ORRs) and water oxidation reactions. Building on these advantages, recent research has gradually evolved from the isolated generation of H₂O₂ to the development of integrated bifunctional systems that utilize H₂O₂ in situ for synergistic applications. This mini-review aims to encapsulate the recent advancements in COF-based materials-mediated dual-function photocatalysis, which couples H₂O₂ production with processes such as pollutant degradation, uranium extraction, organic synthesis, and hydrogen evolution. It examines the rational design strategies and reaction mechanisms of these bifunctional COFs and discusses the prevailing challenges and future research directions.

The production of lithium-ion batteries is increasing consistently, primarily driven by the booming consumer electronics sector and the electrification of the automotive industry. Lithium (Li) is a vital raw material and an essential component in battery production. The limited availability of natural resources, risks associated with material supply, and price volatility render the recycling of Li from used lithium-ion batteries a crucial objective for enhancing environmentally conscious battery production. Reliable and sustainable methods for Li recovery from spent batteries are essential for the future industrial and ecological landscape globally. The majority of research focuses on recovering valuable Li metal by hydrometallurgical processes, with just a limited number of studies addressing bioleaching. This study presents bioleaching-mediated Li recovery from LFP-based commercial black masses at higher solid content, utilizing the autotrophic bacterium Acidithiobacillus thiooxidans. Inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis demonstrated a 90% Li recovery from two distinct commercial black masses within 6 to 24 h at a pulp density of 100-150 g/L. X-Ray diffraction (XRD) and scanning electron microscopy (SEM) studies of the LFP black masses, both pre- and post-bioleaching, confirmed that most of the Li was extracted from the black masses.

Wash-free fluorescent probes are highly desirable in bioimaging due to their ability to simplify analytical procedures, shorten detection time, and avoid potential interference or analyte loss caused by washing steps. In this work, we designed and synthesized a donor-π-acceptor (D-π-A) fluorescent molecule, TB-PY, which exhibits strong solvatochromism and a twisted intramolecular charge transfer (TICT) character. Its water-soluble derivative, TBPYS, was subsequently prepared via quaternization of the pyridine unit. TBPYS displays environmentally sensitive near-infrared (NIR) emission, where its fluorescence is effectively quenched in aqueous media but significantly turned on in low-polarity environments due to suppression of the TICT process. This polarity-responsive property was harnessed for wash-free cell imaging. As demonstrated in live Hep-G2 cells, the TBPYS probe produces bright fluorescence in the hydrophobic cytoplasm while remaining dark in the extracellular aqueous environment, enabling high-contrast imaging directly after staining without any washing steps. An outstanding signal-to-noise ratio of 16 was achieved, underscoring the potential of TBPYS as a practical and efficient probe for wash-free bioimaging applications.

Inspired by natural photosynthesis, researchers are currently focused on light as a renewable energy source for designing Z-schemes for CO₂ valorization. Porphyrin present in the chlorophyll plays a crucial role in natural light harvesting during photosynthesis for CO₂ fixation. An analogue of porphyrin, Metallo phthalocyanine was utilized to fabricate a Z-scheme for CO₂ reduction_. Metallo phthalocyanines acted as a promising photocatalyst and an efficient photosensitizer owing to their absorption in the NIR-I region, ability to generate ROS upon light illumination, and easy property modulation by changing the central metal atom or peripheral/nonperipheral substitution with electron donor or acceptor groups. In the research of CO₂ valorization, an application of phthalocyanines as a photocatalyst or a photosensitizer to create a heterojunction integrating with a suitable semiconductor is continuously rising. Primarily, phthalocyanine-based heterojunctions were designed based on metal oxides, C₃N₄, GO semiconductors or COFs typically suitable for CO₂ to CO transformation. However, a fewer approach for CO₂ reduction to make a variety of value-added products such as CH₄, CH₃OH, HCOOH, C₂H₅OH, and CH₃COOH was also reported. In this article, the role of phthalocyanine, both as a photocatalyst and a photosensitizer, in the designing of an efficient Z-scheme for CO₂ valorization were critically reviewed.

The development of sustainable and efficient methodologies for the synthesis of formamides is of great significance due to their widespread use as intermediates in pharmaceuticals, agrochemicals, and fine chemicals. Herein, a cobalt phosphide (Co_xP) has been developed via a facile annealing method and further employed for one-pot reductive N-formylation of nitroarenes to form N-phenylformamides using formic acid as a biorenewable hydrogen source formed via a dehydrogenation pathway and formylation source. In addition, a catalyst-free protocol was also developed for the direct N-formylation of aromatic amines to their corresponding N-phenylformamides. A broad range of nitroarenes and aromatic amines with varying substituents were successfully transformed into corresponding formamides. Furthermore, the structure-activity relationship was also discussed to correlate the properties of the catalyst with its performance toward the reductive N-formylation reaction. Green metrics parameters were evaluated to analyze the environmental impact and sustainability of the developed reaction protocol. An optimum value of renewable percentage for the developed reaction protocols suggests that the majority of the materials used in the reaction process were derived from renewable sources. Overall, this work provides an eco-friendly route to form N-phenyl formamides, showcasing the potential of Co_xP in advancing non-noble metal-based heterogeneous catalysis for organic transformation reactions.

Dentin hypersensitivity (DH) arises from exposure of dentinal tubules, and tubular occlusion is regarded as the most effective therapy. Bioactive glasses (BGs) that can produce hydroxyapatite (HAp) minerals through reacting with saliva provide a potential opportunity for sustainable tubular occlusion. Although effective, the promotion of BGs in DH treatment has been long suffering from their poor maneuverability in practice. Here we employ a pH neutral BGs composed of a ternary Ca-P-Si system, denoted as PSC, and integrate it into a polyvinyl alcohol hydrogel to construct a composite system that achieves stable tubular occlusion through induced HAp formation. The hydrogel is composed of a nanofibrous network prepared by a two-step solvent exchange process, thus robustly anchoring the PSC particles to extend its intraoral retention. Its favorable aqueous permeability guarantees a free yet effective transportation of mineral precursors. In addition, the composite hydrogel preserves rapid mineralization activity, inducing HAp formation and efficiently occluding exposed tubules in vitro. These features position the composite hydrogel as a promising minimally invasive strategy for durable management of DH.

Over the decades, the outstanding reactivity of Fischer carbene complexes (FCCs) has fascinated those devoted to synthesizing intricate chemical architectures. Among the numerous features of these species, the commonly unexpected rearrangement processes deserve special attention, in which the metal (Cr, Mo, W, and others) plays a crucial role. On the one hand, this review provides a categorized overview of the topic, presenting the most critical information available over the last 25 years. Furthermore, it serves as a guide to understanding the nuances between the reactivity of the metals themselves. The [1,2]-, [1,3]-, and [1,5]-shifts are significant rearrangements intrinsic to FCCs and can be modulated by secondary agents and conditions (thermal, photochemical, etc.). At the same time, this compilation includes a division focusing on cases in which migration occurred within the organic frame but whose procedure was promoted by the metal center. The final section highlights the high potential of these chemical phenomena and opens the pathway to explore their scope, particularly in future synthetic applications.