Chemistry - An Asian Journal最新文献

Driven by accelerating global warming and the imperative of carbon neutrality, the search for efficient electrochemical energy-conversion technologies has intensified. Recent advances in electrocatalysis have introduced strategies to overcome kinetic, selectivity, and stability constraints in the carbon dioxide reduction reaction, oxygen reduction reaction, and water splitting. These developments range from atomic-scale structural modulation to microenvironment engineering, yielding substantial gains in product selectivity, reduced overpotential, and enhanced operational durability. This review consolidates representative breakthroughs across these three reaction domains and emphasizing design principles that couple performance optimization with mechanistic insight through operando X-ray absorption spectroscopy (XAS) and Raman spectroscopy. XAS resolves chemical states and local coordination environments, while Raman tracks surface-bound intermediates; together, they enable a comprehensive elucidation of catalytic mechanisms. The review also outlines key directions for advancing efficient, robust, and scalable electrochemical energy-conversion systems.

This work reports on the discovery of new materials in the Sc_2-x-yFe_xAl_yW₃O₁₂ family. Members with compositions containing high concentrations of Fe are found to crystallize to a structure in the monoclinic P2₁/a symmetry, while compositions with low values of Fe and Al crystallize in the orthorhombic Pnca structure at room temperature. The orthorhombic samples in the compositional range x = 0.5, y ≤ 0.5 are found to transition to the monoclinic P2₁/a structure at 210–230 K. Specifically, Sc_1.25Fe_0.5Al_0.25W₃O₁₂ is found to exhibit a volumetric coefficient of thermal expansion (CTE) of −0.48(7) × 10⁻⁶ K⁻¹ over the range 300–1000 K, a near-zero thermal expansion material—this CTE value is lower than precision invar variants and it is persistent over seven times the temperature range. Increasing the Al concentration to y = 0.75 increases the CTE to 4.69(8) × 10⁻⁶ K⁻¹ over the range 300–1000 K and decreasing it to y = 0 decreases the CTE to −4.22(6) × 10–6 K⁻¹ over the range 300–1000 K. This work probes the phase-space with an intention to correlate doping regimes to the physical property of volume change.

A facile, high-yielding synthetic protocol has been developed to access azepino-fused porphyrins via iodine(III)-mediated oxidative intramolecular cyclization of β-imidazole or benzimidazole substituted porphyrins. The absorption of the synthesized compounds showed the characteristic features of meso-β-fused porphyrins, with intense Soret bands centered between 440 and 460 nm and two weak bands ranging from 550 to 750 nm (Q-bands) Among the synthesized compounds, the free-base imidazo-azepino-fused porphyrin was found to be an efficient ¹O₂ producer with a higher singlet oxygen quantum yield (Φ_Δ ∼0.78 in DMF) as compared to H₂TPP (Φ_Δ = 0.64 in DMF). It was observed that the protonated form of 4aH₂ exhibits a significant red shift of ∼24 nm in Soret and ∼150 nm in Q-bands. Fitting of the titration data of 4aH₂ with TFA yielded an apparent pK_a of ∼3.58, demonstrating that imidazole fusion enhances the basicity of the porphyrin system.

Recent advancements in supercapacitors (SCs) have sparked significant interest due to their exceptional electrochemical performance, high power density, fast charge–discharge rates, and long cycling life. As renewable energy sources emerge as eco-friendly alternatives to fossil fuels, improving energy storage technologies is crucial for meeting rising electricity demands. This review highlights the role of 2D inorganic nanostructure materials in enhancing SC performance, with a focus on materials like graphene, MXene, metal oxides, phosphides, and transition metal dichalcogenides (TMDs) based on molybdenum and tungsten. In particular, the unique structure of 2D materials offers increased ion accessibility and faster electron transport, which are crucial for improving charge-discharge efficiency and rate capability. The potential of 2D inorganic nanostructures in the design of next-generation supercapacitors, focusing on their ability to optimize energy storage mechanisms, including double-layer capacitance and pseudo-capacitance. It discusses the impact of active mass loading and compares the performance of different SC types, including electrochemical double-layer capacitors, hybrid supercapacitors, and pseudo-capacitors. Emphasis is placed on the synthesis techniques, including sol–gel, hydrothermal, CVD, and electro-polymerization, highlighting their influence on material properties and performance. Finally, comprehensive overview of SC electrode material applications is provided, emphasizing their potential in energy storage systems for sustainable development.

We develop an efficient palladium-catalyzed decarboxylative C─H alkenylation of cyclohexa-2,5-dienyl carboxylic acids with allylic alcohols and N-allyl sulfonamides, enabling regioselective access to diverse vinylarenes. The transformation proceeds under mild, operationally simple conditions and tolerates a broad range of alkyl, aryl, and heteroaryl substituents. Mechanistic studies reveal that the reaction is going via carboxylate-directed C─H activation and olefin insertion step. The method is scalable and offers a practical route to vinylarene scaffold-containing biologically relevant moieties.

To further improve the antibacterial performance of photocatalytic paper, a BiOBr/g-C₃N₄ photocatalyst was synthesized via a two-step method, involving calcination for g-C₃N₄ preparation followed by a solvothermal process for BiOBr/g-C₃N₄ composite formation. The BiOBr/g-C₃N₄ photocatalytic paper was fabricated by loading sunflower stalk pulp with a self-made hot-pressing device. In the composite, BiOBr and g-C₃N₄ form tight heterojunctions through close contact, facilitating efficient charge separation and enhancing visible-light utilization. The resulting photocatalytic paper exhibits excellent recyclability and strong antibacterial activity, achieving 99.99% antibacterial efficiency and extending the fruit preservation time by fourfold compared with the control group. This study provides a green and scalable approach for developing recyclable and biodegradable photocatalytic packaging materials with potential applications in sustainable food preservation.

The fast and selective oxidation protocol using cerium ammonium nitrate (CAN) in acetonitrile (MeCN) under ambient temperature and pressure was established. The primary features of this protocol include excellent substrate adaptability, gram-scale preparation with high productivity, and fast and selective oxidation of sulfides to sulfoxides. The mechanism of this reaction was demonstrated to involve a radical process. This protocol provides a fast and straightforward method for the oxidation of sulfides.

The delamination of LiCoO₂ (LCO) films on stainless steel (SS) substrates has remained a critical bottleneck for advancing all-solid-state thin-film lithium batteries (TFLBs). Here, we introduce a stress-engineering approach that fundamentally resolves this challenge through simultaneous monitoring, regulation, and utilization of film stress. In situ stress measurements revealed a universal transition of LCO films from tensile to compressive states during growth, with residual compressive stress in amorphous films originating from an “atomic pinning” mechanism. Among deposition parameters, working pressure was identified as the dominant factor for stress tuning, enabling precise control of stress evolution. Complementarily, substrate pre-annealing at 800°C in Ar released residual stresses and stabilized the SS surface, while moderate post-annealing of LCO films at 550°C preserved both mechanical integrity and electrochemical performance. This dual strategy effectively suppressed crack formation and delamination, yielding robust SS/LCO thin-film electrodes. By scaling this process to square-meter–scale SS/LCO/LiPON multilayers, all-solid-state TFLB cells were successfully fabricated, delivering an initial areal capacity of 38.4 µAh/(cm²·µm) and retaining 97.1% capacity after 1000 cycles. This work not only elucidates the intrinsic stress evolution and its atomic origins in LCO thin films but also pioneers a scalable route toward mechanically resilient, high-performance TFLBs.