Modulation of acid-induced pea protein gels by gellan gum and glucono-δ-lactone: Rheological and microstructural insights.

This study investigated the effect of gellan gum (GG) and glucono-δ-lactone (GDL) on the acid-induced gel properties of pea protein isolate (PPI) pretreated with media milling. The inclusion of GG substantially enhanced the gel hardness of PPI gel from 18.69 g to 792.47 g though slightly reduced its water holding capacity (WHC). Rheological analysis showed that GG increased storage modulus (G') and decreased damping factor of gels in the small amplitude oscillatory shear region and transformed its strain thinning behavior into weak strain overshoot behavior in the large amplitude oscillatory shear region. SEM revealed that GG transformed the microstructure of gel from a uniform particle aggregate structure to a chain-like architecture composed of filaments with small protein particles attached. Turbidity and zeta potential analysis showed that GG promoted the transformation of PPI from a soluble polymer system to an insoluble coagulant during acidification. When GG content was relatively high (0.2 %-0.3 %), high GDL content increased the electrostatic interaction between PPI and GG molecules, causing their rapid aggregation into a dense irregular aggregate structure, further enhancing gel strength and WHC. Overall, GG and GDL can offer the opportunity to modulate the microstructure and gel properties of acid-induced PPI gels, presenting potential for diversifying food gel design strategies through PPI-GG hybrid systems.

Chiral phosphoric acid-catalyzed asymmetric epoxidation of alkenyl aza-heteroarenes using hydrogen peroxide.

The synthesis of chiral α-azaheteroaryl oxiranes via enantioselective catalysis is a formidable challenge due to the required complex stereoselectivity and diverse N-heterocyclic structures. These compounds play a crucial role in developing bioactive molecules, where precise chirality significantly influences biological activity. Here we show that using chiral phosphoric acid as a catalyst, our method efficiently addresses these challenges. This technique not only achieves high enantio- and diastereoselectivity but also demonstrates superior chemo- and stereocontrol during the epoxidation of alkenyl aza-heteroarenes. Our approach leverages a synergistic blend of electrostatic and hydrogen-bonding interactions, enabling the effective activation of both substrates and hydrogen peroxide. The resulting chiral oxiranes exhibit enhanced diversity and functionality, aiding the construction of complex chiral azaaryl compounds with contiguous stereocenters. Kinetic and density functional theory studies elucidate the mechanism, highlighting chiral phosphoric acid's pivotal role in this intricate enantioselective process.

Precursor Induced Assembly of Si Nanoparticles Encapsulated in Graphene/Carbon Matrices and the Influence of Al2 O3 Coating on their Properties as Anode for Lithium-Ion Batteries.

The theoretical capacity of pristine silicon as anodes for lithium-ion batteries (LIBs) can reach up to 4200 mAh g-1 , however, the low electrical conductivity and the huge volume expansion limit their practical application. To address this challenge, a precursor strategy has been explored to induce the curling of graphene oxide (GO) flakes and the enclosing of Si nanoparticles by selecting protonated chitosan as both assembly inducer and carbon precursor. The Si nanoparticles are dispersed first in a slurry of GO by ball milling, then the resulting dispersion is dried by a spray drying process to achieve instantaneous solution evaporation and compact encapsulation of silicon particles with GO. An Al2 O3 layer is constructed on the surface of Si@rGO@C-SD composites by the atomic layer deposition method to modify the solid electrolyte interface. This strategy enhances obviously the electrochemical performance of the Si as anode for LIBs, including excellent long-cycle stability of 930 mAh g-1 after 1000 cycles at 1000 mA g-1 , satisfied initial Coulomb efficiency of 76.7%, and high rate ability of 806 mAh g-1 at 5000 mA g-1 . This work shows a potential solution to the shortcomings of Si-based anodes and provides meaningful insights for constructing high-energy anodes for LIBs.

Carbon Nanofibers Decorated by MoS2 Nanosheets with Tunable Quantity as Self-Supporting Anode for High-Performance Lithium Ion Batteries.

Two-dimensional molybdenum disulfide (MoS2) is considered as a highly promising anode material for lithium-ion batteries (LIBs) due to its unique layer structure, large plane spacing, and high theoretical specific capacity; however, the overlap of MoS2 nanosheets and inherently low electrical conductivity lead to rapid capacity decay, resulting in poor cycling stability and low multiplicative performance. This severely limits its practical application in LIBs. To overcome the above problems, composite fibers with a core//sheath structure have been designed and fabricated. The sheath moiety of MoS2 nanosheets is uniformly anchored by the hydrothermal treatment of the axial of carbon nanofibers derived from an electrospinning method (CNFs//MoS2). The quantity of the MoS2 nanosheets on the CNFs substrates can be tuned by controlling the amount of utilized thiourea precursor. The influence of the MoS2 nanosheets on the electrochemical properties of the composite fibers has been investigated. The synergistic effect between MoS2 and carbon nanofibers can enhance their electrical conductivity and ionic reversibility as an anode for LIBs. The composite fibers deliver a high reversible capacity of 866.5 mA h g-1 after 200 cycles at a current density of 0.5 A g-1 and maintain a capacity of 703.3 mA h g-1 after a long cycle of 500 charge-discharge processes at 1 A g-1.

Skin-like cryogel electronics from suppressed-freezing tuned polymer amorphization.

The sole situation of semi-crystalline structure induced single performance remarkably limits the green cryogels in the application of soft devices due to uncontrolled freezing field. Here, a facile strategy for achieving multifunctionality of cryogels is proposed using total amorphization of polymer. Through precisely lowering the freezing point of precursor solutions with an antifreezing salt, the suppressed growth of ice is achieved, creating an unusually weak and homogenous aggregation of polymer chains upon freezing, thereby realizing the tunable amorphization of polymer and the coexistence of free and hydrogen bonding hydroxyl groups. Such multi-scale microstructures trigger the integrated properties of tissue-like ultrasoftness (Young's modulus <10 kPa) yet stretchability, high transparency (~92%), self-adhesion, and instantaneous self-healing (<0.3 s) for cryogels, along with superior ionic-conductivity, antifreezing (-58 °C) and water-retention abilities, pushing the development of skin-like cryogel electronics. These concepts open an attractive branch for cryogels that adopt regulated crystallization behavior for on-demand functionalities.

Pd-Enriched-Core/Pt-Enriched-Shell High-Entropy Alloy with Face-Centred Cubic Structure for C1 and C2 Alcohol Oxidation.

High-entropy alloy nanoparticles (HEA NPs) have aroused great interest globally with their unique electrochemical, catalytic, and mechanical properties, as well as diverse activity and multielement tunability for multi-step reactions. Herein, a facile low-temperature synthesis method at atmospheric pressure is employed to synthesize Pd-enriched-HEA-core and Pt-enriched-HEA-shell NPs with a single phase of face-centred cubic structure. Interestingly, the lattice of both Pd-enriched-HEA-core and Pt-enriched-HEA-shell enlarge during the formation process of HEA, with tensile strains included in the core and shell of HEA. The as-obtained PdAgSn/PtBi HEA NPs show excellent electrocatalytic activity and durability for methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). The specific (mass) activity of PdAgSn/PtBi HEA NPs for MOR is 4.7 mA cm-2 (2874 mA mg(Pd+Pt) -1 ), about 1.7 (5.9) and 1.5 (4.8) times higher than that of commercial Pd/C and Pt/C catalysts, respectively. Additional to high-entropy effect, Pt sites and Pd sites on the interface of the HEA act synergistically to facilitate the multi-step process towards EOR. This study offers a promising way to find a feasible route for scalable HEA manufacturing with promising applications.

Electrochemical Activation of Nitromethane to Construct Isoxazoline Aldoximes.

Activation of nitromethane to endow new reactivity is an interesting and meaningful but also challenging topic. Herein, we report an electrochemical activation of nitromethane to serve as both the heterocyclic skeleton and oxime sources for the construction of isoxazoline aldoximes. The isoxazoline aldoximes that are prepared by four steps with the reported strategy are synthesized in a single step from low-cost and readily available nitromethane and olefins with moderate to excellent yields under our electrochemical conditions. The reaction also takes advantage of high atom-economy and E-selectivity. Moreover, the mechanism is studied by control experiments, a kinetic isotope effect (KIE) study, cyclic voltammogram (CV) experiments, and density functional theory (DFT) calculations. The mechanistic results reveal that nitromethane may be activated under electrochemical conditions to deliver a 1,2,5-oxadiazole 2-oxide intermediate, which undergoes [3+2] cycloaddition with olefins to yield isoxazoline aldoximes.

Proton-mediated reversible switching of metastable ferroelectric phases with low operation voltages.

The exploration of ferroelectric phase transitions enables an in-depth understanding of ferroelectric switching and promising applications in information storage. However, controllably tuning the dynamics of ferroelectric phase transitions remains challenging owing to inaccessible hidden phases. Here, using protonic gating technology, we create a series of metastable ferroelectric phases and demonstrate their reversible transitions in layered ferroelectric α-In2Se3 transistors. By varying the gate bias, protons can be incrementally injected or extracted, achieving controllable tuning of the ferroelectric α-In2Se3 protonic dynamics across the channel and obtaining numerous intermediate phases. We unexpectedly discover that the gate tuning of α-In2Se3 protonation is volatile and the created phases remain polar. Their origin, revealed by first-principles calculations, is related to the formation of metastable hydrogen-stabilized α-In2Se3 phases. Furthermore, our approach enables ultralow gate voltage switching of different phases (below 0.4 volts). This work provides a possible avenue for accessing hidden phases in ferroelectric switching.

Microspheres of Si@Carbon-CNTs composites with a stable 3D interpenetrating structure applied in high-performance lithium-ion battery.

The huge volumetric expansion (>300 %) of Si that occurs during the charge-discharge process makes it to have poor cycling ability and weak stable structure. These factors are considered as critical obstacles to the further development of Si as anode for lithium-ion batteries (LIBs). Herein, novel 3D interpenetrating microspheres, i.e., Si@C-CNTs, which consist of silicon nanoparticles interpenetrated with carbon nanotubes (CNTs) and stuck with amorphous carbon (C) have been designed and prepared via a spray-drying assisted approach. As anode of LIBs, Si@C-CNTs microspheres can achieve high silicon loadings of around 86 % and a high initial coulomb efficiency of 80.8 %. The electrodes maintain a reversible specific capacity of 1585.9mAh/g at 500 mA g-1 after 200 cycles, and deliver an excellent rate capability of 756.4 mAh/g at 5 A g-1. The outstanding performance of Si@C-CNTs can be due to their 3D interpenetrating structure and the synergy effect between the CNTs network and amorphous carbon therein. They synergistically act as conductive matrices which significantly improve the conductivity of the composite; they also act binders and reinforcing skeleton which help the composite spheres to have stable structure. Especially, the latter (reinforcing skeleton) alleviates the volumetric effect induced by the expansion and shrinkage of silicon particles during lithiation. The unique architecture provides an ideal model that can be used to design Si-based composite anode for advanced LIBs.