Chemical Stability Research Articles

Dicyclopenta[4,3,2,1-cde:4',3',2',1'-pqr]-peri-tetracene: Synthesis and An Example of Annulene-Within-An-Annulene Aromaticity in Different Redox States.

We report a robust strategy for tuning the electronic structure and chemical stability of π-conjugated polycyclic hydrocarbons (PHs). By fusing two cyclopentadienyl rings in the peri-tetracene bay regions, we introduce antiaromatic character into the π-system, leading to unique photophysical and electronic properties. A stable mesityl-substituted dicyclopenta-peri-tetracene derivative was synthesized through stepwise formylation/intramolecular cyclization at the bay regions of the dihydro peri-tetracene precursor, followed by oxidative dehydrogenation. This compound features an open-shell singlet diradical ground state, global antiaromaticity, exceptional stability under ambient conditions, and amphoteric redox behavior with a small energy gap. Its dication also possesses an open-shell singlet ground state, and its structure was identified by X-ray crystallographic analysis, revealing a unique [14]annulene-within-[22]annulene global aromatic structure. In contrast, the dianion exhibits a closed-shell singlet ground state. This work provides valuable insights for designing and synthesizing novel open-shell PHs with tunable electronic structures and remarkable stability.

Co@NC Chainmail Nanowires for Thermo- and Electrocatalytic Oxidation of 2,5-Bis(hydroxymethyl)furan to 2,5-Furandicarboxylic Acid.

2,5-Furandicarboxylic acid (FDCA) has emerged as an important bio-based furanic compound, which has broad application prospects in renewable energy and materials, especially in the preparation of polyethylene 2,5-furandicarboxylate (PEF). While the conventional synthesis of FDCA involves oxidation of 5-hydroxymethylfurfural (HMF) as a substitute, the thermal and chemical instability of HMF due to its aldehyde group poses challenges. A more favorable alternative is the utilization of 2,5-bis(hydroxymethyl)furan (BHMF), a non-aldehyde and more stable precursor. This study pioneeringly reports nitrogen-doped-carbon encapsulated cobalt (Co@NC) chainmail nanowires for the thermal and electrocatalytic oxidation of BHMF to FDCA. The Co@NC/NF achieved a 97.9 % conversion of BHMF with a 93.3 % yield of FDCA at 1.475 V vs. RHE, whereas thermal catalysis only obtained 14.9 % FDCA yield after 10 hours. Kinetic studies indicated that the large electrochemically active surface area and excellent kinetic parameters contribute its superior electrochemical performance. Mechanistic analysis revealed that the migration of inner electrons to the exterior modified the electronic properties of the carbon layer, thereby facilitating the oxidation of BHMF. Furthermore, the in-situ generation of high-valent cobalt species markedly accelerated the BHMF oxidation. This research underscores the potential of carbon-encapsulated metal chainmail catalysts in thermal and electrochemical biomass conversion.

Novel Anodic TiO2 Synthesis Method with Embedded Graphene Quantum Dots for Improved Photocatalytic Activity

Photocatalytic degradation of pollutants have a high potential for sustainable and renewable uses. TiO2 is a widely studied photocatalyst due to its high chemical and photochemical stability and wide range of applications. However, the wide band gap and low capacity of photo-induced charge separation provide lower catalytic activity; thus, improvement of these properties must be found. The doping of TiO2 with other elements, such as carbon nanoparticles (CNP) in a quantum dot form, offers a promising pathway to improve the aforementioned properties. In addition, in situ doping methods should be investigated for practical scalability, as they offer the advantage of integrating dopants directly during material synthesis, ensuring a more uniform distribution and better interaction between the dopant and the host material, in turn leading to more consistent photocatalytic properties. Current technologies primarily involve nanoparticle combinations. This work focuses on the development of a novel in situ synthesis methodology by the introduction of three different graphene-based quantum nanodots into anodic TiO2 and the following investigation of structural, morphological, and photocatalytic properties. Results indicate that the introduction of CNP allows for the shift of a set of parameters, such as the optical band gap, increased photo-induced charge carrier density of TiO2/CNP composite, and, most importantly, the change of crystalline phase composition depending on added CNP material. Research indicates that not only a higher concentration of added CNP enhances higher photocatalytic activity as tested by the degradation of methylene blue dye, but also the type of CNP determines final crystalline phase. For the first time brookite and rutile phases were obtained in anodic titania synthesized in inorganic electrolyte by introducing hydrothermally treated exfoliated graphene.

Crystal structure, structural geometry, and molecular motion of organic–inorganic perovskite [N(CH3)4]2MnCl4 crystals at phases I, II, and III

Various aspects of the new development of organic-inorganic hybrid [N(CH3)4]2MnCl4 single crystals have been discussed. The phase transition temperatures were determined to be 268 K (TC2) and 291 K (TC1), and the thermodynamic stability was maintained at temperatures up to 669 K. The crystal structures at 250 K (phase III), 275 K (phase II), and 300 K (phase I) are monoclinic, orthorhombic, and orthorhombic, respectively. Notably, while the 1H and 13C chemical shifts gradually changed near TC1 and TC2, the 14N resonance frequency exhibited a split in the number of signals near TC1. Furthermore, the shorter spin-lattice relaxation time T1ρ of 1H than that of 13C suggests facile energy transfer for1H. Additionally, analysing the temperature dependencies of T1ρ for 13C revealed that the activation energy Ea in phase I is approximately five times greater than those in phases III and II. The high Ea observed in phase I primarily stems from the collective motion of the N(CH3)4 group, which contrasts with the considerable freedom observed for the CH3 group in phases III and II. These distinctive physical properties suggest potential applications for [N(CH3)4]2MnCl4 as an organic‒inorganic hybrid material.

Study of lanthanide based Ln2MgSe4 (Ln = Er, Pm) spinels for spintronic and optoelectronic applications

Abstract Herein, the full potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory (DFT) is used to examine the physical features of Ln2MgSe4 (Ln = Er, Pm) spinel selenides. Exchange correlation energies are estimated through modified Becke–Johnson potential (mBJ). Band structures (BS) and density of states (DOS) data proved that Er2MgSe4 is ferromagnetic (FM) semiconductor while Pm2MgSe4 is half metallic (HFM) ferromagnetic in nature. The Er-f contributed majorly to the vicinity of Fermi level for both compounds. The structural stability is determined through calculating the tolerance factor and geometry optimization, while thermodynamical stability has been realized by computing the formation enthalpy. Furthermore, various optical parameters have been computed which describe the considered materials’ response to incident light. Our study explored the physical properties of two Ln based spinels which are found to have potential for being used in various optoelectronic and spintronic devices.

Guide for Nonequilibrium Molecular Dynamics Simulations of Organic Solvent Transport in Nanopores: The Case of 2D MXene Membranes.

Organic solvent nanofiltration (OSN) stands out as an energy-efficient and low-carbon footprint technology, currently reliant on polymeric membranes. With their exceptional chemical stability and tunable sieving properties, two-dimensional (2D) nanolaminate membranes present distinct advantages over conventional polymer-based membranes, attracting tremendous interest in the OSN community. Computational approaches for designing innovative 2D nanolaminates exhibit significant potential for the future of OSN technology. Imitating the pressure gradient in filtration processes by applying an external force to atoms within a predefined slab, boundary-driven nonequilibrium molecular dynamics ((BD)-NEMD) is a state-of-the-art simulation method with a proven track record in investigating the water transport in nanopores. Nevertheless, implementation of (BD)-NEMD for a broad range of solvents poses a challenge in estimating the OSN performance of theoretical membranes. In this work, we developed a (BD)-NEMD protocol that elucidates the effects of several computational details often overlooked in water simulations but are crucial for bulky solvent systems. We employed a MXene (Ti3C2O2) nanochannel as a model membrane and examined the transport of nine solvents (methanol, ethanol, acetone, n-hexane, n-heptane, toluene, ethyl acetate, dichloromethane, and water) having different properties. First, the impact of ensemble type, thermostatting, channel wall model, and restraining force constant was elaborated. After optimizing the thermostatting approach, we demonstrated that the location of the force slab particularly affects the flux of bulky solvents by changing the density distribution in the feed and permeate sides. Similarly, the uniformity of intramolecular force distribution in bulky solvents and resulting flux are shown to be prone to manipulation by slab boundaries. Next, the magnitudes of the external force generating a linear relation between the pressure gradient and solvent flux were identified for each solvent to ensure that calculated fluxes could be extrapolated to experimentally related pressures. This linear relation was also validated for a mixture system containing 50% ethanol and 50% water. We then correlated the calculated solvent permeances with various solvent properties, such as viscosity, Hansen solubility parameters, kinetic diameter, and interaction energy. Remarkably, we observed a linear correlation with an R2 value of 0.96 between permeance and the combined parameter of viscosity and interaction energy. Finally, the solvent permeances calculated with our proposed methodology closely align with the experimentally reported data. Overall, our work aims to serve as a practical guide and bridge the gap in established simulation methods that are suited for a broad range of solvents and membrane materials.

A Fe3+-Doped TiO2 Superhydrophilic Coating with Transparent and Long-Lasting Antifogging Properties Constructed Based on Nanostructured Antireflective and Capillary Anchoring Effects.

Superhydrophilic surfaces have attracted great interest in antifogging applications. However, balancing long-lasting superhydrophilicity and high transparency on antifogging surfaces remains a serious problem to be solved. The objective of this work is to prepare superhydrophilic coatings with transparent and long-lasting antifogging properties. In the design, a three-step method was used to obtain the target coatings: (1) magnetron sputtering deposition of a TiN film to provide high intensity, (2) anodic oxidation of the TiN film to obtain TiO2 nanoparticles intended for nanostructured antireflective and capillary structures, and (3) the sol-gel method for the preparation of Fe3+-doped TiO2 coatings using spin-coating in order to achieve superhydrophilicity. The nanostructures, due to their subwavelength dimensions, not only provide high transparency but also recoverable superhydrophilicity owing to the presence of a capillary anchoring effect that prevents the coating from dissolving and peeling off after soaking. The doping of Fe3+ broadened the photoresponse range and maintained the long-lasting superhydrophilicity. Tests showed that the 2 mol % Fe3+-doped TiO2 coating with nanostructures exhibited the highest transparency, longest-lasting superhydrophilicity, and antifogging properties. Furthermore, the coating provided excellent self-cleaning properties, as well as mechanical and chemical stability.

Misfit Layered Compounds: Insights into Chemical, Kinetic, and Thermodynamic Stability of Nanophases.

ConspectusCompounds with layered structures (2D-materials), like transition metal-dichalcogenides (e.g., MoS2), attracted a great deal of interest in the scientific community in recent years. This interest can be attributed to their unique lamellar structure, which induces large anisotropy in their physicochemical properties. Furthermore, owing to the weak van der Waals interaction between the layers, they can be cleaved along the a-b plane, which allows fabricating single layers with physical properties entirely different from the bulk material. Moreover, stacking layers of different 2D-materials on top of each other has led to a wealth of new observations, for instance, by twisting two layers with respect to each other and producing Moiré lattice. Another outstanding property of inorganic layer compounds is their tendency to form nanotubes, reported first (for WS2) many years ago and subsequently from many other layered compounds.Among the 2D-materials, misfit layer compounds make a special class with an incommensurate and nonstoichiometric lattice made of an alternating layer with rocksalt structure, like LaS (O) and a layer with hexagonal structure, like TaS2 (T). The lack of lattice commensuration between the two slabs leads to a built-in strain, which can be relaxed via bending. Consequently, nanotubes have been produced from numerous MLC compounds over the past decade and their structure was elucidated.Owing to their large surface area, nanostructures are generally metastable and tend to recrystallize into microscopic crystallites via different mechanisms, like Ostwald ripening, or chemically decompose and then recrystallize. The stability of nanostructures at elevated temperatures has been investigated quite scarcely so far. In this perspective, electron microscopy as well as synchrotron-based X-ray absorption and reflection techniques were used to elucidate the chemical selectivity and decomposition routes of rare-earth based MLC nanotubes prepared at elevated temperatures (800-1200 °C).As for the chemical selectivity, entropic effects are expected to dictate the random distribution of the chalcogen atoms on the anion sites of the MLC nanotubes at elevated temperatures. Nonetheless, the sulfur atoms were found to bind exclusively to the rare-earth atom (Ln = La, Sm) of the rocksalt slab and the selenium to the tantalum of the hexagonal TX2 slab. This uncommon selectivity was not found in other kinds of nanotubes like WSe2xS2(1-x). In other series of experiments, the lack of utter symmetry in the multiwall nanotubes leads to exclusions of certain X-ray (0kl) reflections, which was used to distinguish them from the bulk crystallites. The transformation of Ln-based MLC nanotubes into microscopic flakes was followed as a function of the synthesis temperature (800-1200 °C) and the synthesis time (1-96 h). Furthermore, sequential high-temperature transformations of the (O-T) lattice into (O-T-T) and finally (O-T-T-T) phases via deintercalation of the LnS slab was observed. This autocatalytic process is reminiscent of the deintercalation of alkali atoms from different layered structure materials. Annealing at higher temperatures and for longer periods of time eventually leads to the decomposition of the ternary MLC into binary metal-sulfide phases, as well as partial oxidation of the product. This study sheds light on the complex mechanism of high-temperature chemical stability of the nanostructures.

Structural, electronic, optical, mechanical, and phononic bulk properties of tetragonal trirutile antimonate MSb2O6 (M = Fe, Co, Ni, or Zn): a first-principles prediction for optoelectronic applications

Abstract This work does an extensive analysis of the optoelectronic and mechanical properties of the tri rutile structure type 3d transition metal Antimonate MSb2O6 (M = Fe, Co, Ni, or Zn), for the first time, utilizing the pseudo-potential plane wave approach within the density functional theory framework. When calculating the structural, optical, and mechanical properties, the exchange–correlation interactions were studied using the GGA-PBE functional, whereas when computing electronic, it is analyzed using the HSE06 hybrid functional. The equilibrium lattice parameters exhibit good agreement with the available experimental results. The electronic properties were estimated using the GGA-PBE and HSE06 functionals. Based on the calculated electronic properties with the GGA-PBE functional, the FeSb2O6, CoSb2O6, and NiSb2O6 materials exhibit metallic behavior with energy gap values of 0 eV, while ZnSb2O6 is a semiconductor with a narrow direct band gap (Γ–Γ) of 0.5 eV. Furthermore, the computed band gaps using the HSE06 functional are 0 eV, 0 eV, 1 eV (Γ–Γ), and 4 eV (Γ–Γ) for FeSb2O6, CoSb2O6, NiSb2O6, and ZnSb2O6, respectively. Density of states diagrams were used to gain deeper insights into the characteristics of the energy bands. The optical properties of these compounds, such as the dielectric function, energy loss function, conductivity, reflectivity, refractive index, and absorption coefficient were investigated over the energy range of 0 to 40 eV. The materials exhibited a high absorption coefficient and a significantly low reflectivity within the UV–vis energy spectrum. The negative cohesive energy Ecoh implies the chemical (thermodynamic) stability of the trirutile MSb2O6 (M = Fe, Co, Ni, or Zn). Mechanical stability is confirmed by applying the Born stability criteria using elastic constants (Cij). The absence of imaginary frequencies in the phonon spectrum calculations confirms the dynamic stability of the studied compounds. These results are consistent with previous experimental research on these materials in photocatalysis and gas sensor applications. On the other hand, these compounds possess exceptional high and broad optical absorption UV range, making them suitable for use in next-generation ultraviolet photodetectors.

Indole N-Linked Hydroperoxyl Adduct of Protein-Derived Cofactor Modulating Catalase-Peroxidase Functions.

Bifunctional catalase-peroxidase (KatG) features a posttranslational methionine-tyrosine-tryptophan (MYW) crosslinked cofactor crucial for its catalase function, enabling pathogens to neutralize hydrogen peroxide during infection. We discovered the presence of indole nitrogen-linked hydroperoxyl adduct (MYW-OOH) in Mycobacterium tuberculosis KatG in the solution state under ambient conditions, suggesting its natural occurrence. By isolating predominantly MYW-OOH-containing KatG protein, we investigated the chemical stability and functional impact of MYW-OOH. We discovered that MYW-OOH inhibits catalase activity, presenting a unique temporary lock. Exposure to peroxide or increased temperature removes the hydroperoxyl adduct from the protein cofactor, converting MYW-OOH to MYW and restoring the detoxifying ability of the enzyme against hydrogen peroxide. Thus, the N-linked hydroperoxyl group is releasable. KatG with MYW-OOH represents a catalase dormant, but primed, state of the enzyme. These findings provide insight into chemical strategies targeting the bifunctional enzyme KatG in pathogens, highlighting the role of N-linked hydroperoxyl modifications in enzymatic function.

Structural Factors for the Chemical Stability of Graft-Type Polymer Electrolyte Membranes Evaluated from the Local Hydration Number

Structural Factors for the Chemical Stability of Graft-Type Polymer Electrolyte Membranes Evaluated from the Local Hydration Number

Supported phenylalanine on core-shell mesoporous microsphere as a catalyst for the synthesis of triazolo[1,2-a] indazole-triones and spiro triazolo[1,2-a] indazole-tetraones

In recent years, mesoporous silica materials have gained attention due to their unique properties, such as high surface area, pore volume, size, and chemical stability. These characteristics make them effective in various fields, particularly efficient supports in heterogeneous catalytic reactions. The present study developed a novel type of core-shell mesoporous microsphere material by anchoring phenylalanine on a core-shell SiO2@NiO@MS support. The catalyst support (SiO2@NiO@MS) was synthesized through homogeneous precipitation and sol-gel methods, with NiO encapsulated within the porous silica. The catalyst was characterized using various techniques, including Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), Elemental mapping analysis, N2 adsorption-desorption, Transmission electron microscopy (TEM), Vibrating sample magnetometer (VSM), and Thermogravimetric analysis (TGA). It was then employed for the synthesis of triazolo[1,2-a]indazole-trione and spiro triazolo[1,2-a]indazole-tetraones compounds from 4-phenyl urazole, dimedone, and aromatic aldehydes or isatin derivatives. This synthetic approach offers multiple advantages, including high yields, faster reaction times, low catalyst requirements, and environmentally sustainable conditions.

Bacterial Cellulose Applications in Electrochemical Energy Storage Devices.

Bacterial cellulose (BC) is produced via the fermentation of various microorganisms. It has an interconnected 3D porous network structure, strong water-locking ability, high mechanical strength, chemical stability, anti-shrinkage properties, renewability, biodegradability, and a low cost. BC-based materials and their derivatives have been utilized to fabricate advanced functional materials for electrochemical energy storage devices and flexible electronics. This review summarizes recent progress in the development of BC-related functional materials for electrochemical energy storage devices. The origin, components, and microstructure of BC are discussed, followed by the advantages of using BC in energy storage applications. Then, BC-related material design strategies in terms of solid electrolytes, binders, and separators, as well as BC-derived carbon nanofibers for electroactive materials are discussed. Finally, a short conclusion and outlook regarding current challenges and future research opportunities related to BC-based advanced functional materials for next-generation energy storage devices suggestions are proposed.

Surface Coating of ZIF-8 Nanoparticles with Polyacrylic Acid: A Facile Approach to Enhance Chemical Stability for Biomedical Applications.

Nanoparticles of zeolitic imidazole framework-8 (ZIF-8 NPs), which are the subclass of metal-organic frameworks consisting of Zn ion and 2-methylimidazole, have been identified as promising drug carriers since their large microporous structure is suited for encapsulating hydrophobic drug molecules. However, one of the limitations of ZIF-8 NPs is their low stability in physiological solutions, especially in the presence of water and phosphate anions. These molecules can interact with the coordinatively unsaturated Zn sites at the external surface to induce the degradation of ZIF-8 NPs. In this study, herein a facile approach is reported to enhance the chemical stability of ZIF-8 NPs by surface coating with polyacrylic acid (PAA). The PAA-coated ZIF-8 (PAA-ZIF-8) NPs are prepared by mixing ZIF-8 NPs and PAA in water. PAA coating inhibits the degradation of ZIF-8 NPs in water as well as phosphate-buffered saline over 6 days, which seems to be due to the coordination of carboxyl groups of PAA to the reactive Zn sites. Furthermore, the PAA-ZIF-8 NPs loaded with the anticancer drug doxorubicin (Dox) show cytotoxicity in human colon cancer cells. These results clearly show the feasibility of the PAA coating approach to improve the chemical stability of ZIF-8 NPs without impairing their drug delivery capability.

Complex Coacervates: From Polyelectrolyte Solutions to Multifunctional Hydrogels for Bioinspired Crystallization

Hydrogels represent multifarious functional materials due to their diverse ranges of applicability and physicochemical properties. The complex coacervation of polyacrylate and calcium ions or polyamines with phosphates has been uncovered to be a fascinating approach to synthesizing of multifunctional physically crosslinked hydrogels. To obtain this wide range of properties, the synthesis pathway is of great importance. For this purpose, we investigated the entire mechanism of calcium/polyacrylate, as well as phosphate/polyamine coacervation, starting from early dynamic ion complexation by the polymers, through the determination of the phase boundary and droplet formation, up to the growth and formation of thermodynamically stable macroscopic coacervate hydrogels. By varying the synthesis procedure, injectable hydrogels, as well as plastic coacervates, are presented, which cover a viscosity range of three orders of magnitude. Furthermore, the high calcium content of the calcium/polyacrylate coacervate (~19 wt.%) enables the usage of those coacervates as an ions reservoir for the formation of amorphous and crystalline calcium-containing salts like calcium carbonates and calcium phosphates. The exceptional properties of the coacervates obtained here, such as thermodynamic stability, viscosity/plasticity, resistance to acids, and adhesive strength, combined with the straightforward synthesis and the character of an ions reservoir, open a promising field of bioinspired composite materials for osteology and dentistry.

Spiro‐Based Thermally Activated Delayed Fluorescence Emitters for Organic Light‐Emitting Diodes

AbstractSpiro structures, possessing unique π‐electron systems, large steric hindrance, high glass transition temperature, and chemical stability, serve as critical structural building blocks in constructing thermally activated delayed fluorescence (TADF) emitters. The incorporation of various heteroatoms such as oxygen, sulfur, and nitrogen in 9,9′‐spirobifluorene generates diverse spiro structures like spiro[fluorene‐9,9′‐xanthene], spiro[fluorene‐9,9′‐thioxanthene], and spiro[acridine‐9,9′‐fluorene]. Based on the charge transfer characteristics, TADF emitters built upon spiro structures can be classified into various types, including twisted intramolecular charge transfer, through‐space charge transfer, multiresonance, and exciplex‐type TADF emitters. This review systematically highlights the recent progress in the research on TADF emitters comprised of spiro‐structured aromatics. It intricately explores the molecular design strategies, material synthesis methods, understanding of photophysical attributes, and analysis of organic light‐emitting diode performance. Concurrently, it sketches out the challenges faced in the commercial application stage while providing an outlook for potential research trajectories.

Enhanced efficiency of carbon based all perovskite tandem solar cells via cubic plasmonic metallic nanoparticles with dielectric nano shells

This study investigates a carbon-based all-perovskite tandem solar cell (AP-TSC) with the structure ITO, SnO₂, Cs₀.₂FA₀.₈Pb(I₀.₇Br₀.₃)₃, WS₂, MoO₃, ITO, C₆₀, MAPb₀.₅Sn₀.₅I₃, PEDOT: PSS, Carbon. The bandgap configuration of the cell is 1.75 eV/1.17 eV, which is theoretically limited to 36% efficiency. The effectiveness of embedding cubic plasmonic metallic nanoparticles (NPs) made of Gold (Au) and Silver (Ag) within the absorber layers to eliminate the requirement for thicker absorber layers, decrease manufacturing costs and Pb toxicity is demonstrated in our analysis. This analysis was conducted using 3D Finite Element Method (FEM) simulations for both optical and electrical calculations. Prior to delving into the primary investigation of the tandem structure, a validation simulation was conducted to demonstrate the accuracy and reliability of the simulations. Notably, the efficiency mismatch observed during the validation simulation, specifically in relation to the incorporation of metallic nanoparticles (NPs), amounted to a mere 0.01%. To mitigate the potential issues of direct contact between metallic NPs and perovskite materials, such as increased thermal and chemical instability and recombination at the NP surface, a 5 nm dielectric shell was applied to the NPs. The incorporation of cubic core-shell Ag NPs resulted in a 15.32% enhancement in short-circuit current density, from 16.39 mA/cm² to 18.90 mA/cm², and a 15.68% increase in overall efficiency, from 26.9 to 31.12%. This research paves the way for the integration of core-shell metallic NPs in AP-TSCs, highlighting a significant potential for efficiency and stability improvements. In a dedicated section the band alignment of the sub-cell was addressed. Additionally, a thermal investigation of the proposed tandem structure was conducted, demonstrating the robustness of the proposed AP-TSC. Finally, the sensitivity analyses related to input parameters and the challenges associated with large-scale fabrication of the proposed AP-TSC were extensively discussed.

Eutectic Strategy for the Solvent-Free Synthesis of Hydrophobic Cellulosic Cross-Linked Networks with Broad Multifunctional Applications.

Cellulose-based functional materials play a crucial role in sustainable social development. However, during the material synthesis process, there is typically significant reliance on various solvent systems for macroscopic- or molecular-scale functionalization modifications. In this study, an innovative hydrophobic eutectic solvent (HES) was developed using ethyl cellulose (EC) and thymol (Thy) without any external solvents. Utilizing this homogeneous system, it is convenient to chemically modify the components without any catalyst. Furthermore, a hydrophobic cellulosic cross-linked network (HCCN) can be successfully prepared through in situ photopolymerization. The HCCN film exhibits high transparency, excellent mechanical properties, chemical stability, and durability. The EC/Thy prepolymer system also demonstrates favorable processability for the preparation of various polymeric materials. Additionally, the applicability of other biomasses and derivatives based on the eutectic strategy has been verified. The methodology proposed in this study offers novel insights into the green and solvent-free preparation of biomass functional materials.

Vitalizing Perovskite Oxide-Based Acetone Sensors with Metal-Organic Framework-Derived Heterogeneous Oxide Catalysts.

Perovskite oxides are promising candidates for chemiresistive-type gas sensors owing to their exceptional thermal and chemical stability during solid-gas reactions. However, perovskites suffer from critical issues such as low surface area and poor surface activity, which negatively influence the sensing characteristics. While metal nanoparticles can be incorporated in perovskites to improve their reactivity, the fundamental incompatibility between catalytic metals and perovskite oxides often leads to substantial structural degradation as well as phase instability. Herein, we overcome this challenge through the introduction of an intermediary phase that forms coherent interfaces with both the perovskite phase and catalyst metals. Specifically, we present the case study of p-type La0.8Ca0.2Fe0.98Pt0.02O3 perovskite, whose hole accumulation layer was modulated by the incorporation of metal-organic framework (MOF)-derived n-type α-Fe2O3 nanoparticles decorated with highly dispersed Pt catalysts. The resulting composite exhibited significantly improved surface activity over the nonmodified La0.8Ca0.2FeO3 perovskite, leading to exceptional chemiresistive sensing performance toward acetone gas (Rg/Ra = 39.8 toward 10 ppm of acetone at 250 °C) with high cross-sensitivity against interfering gases. Importantly, our findings reaffirm the critical influence of interfacial engineering in facilitating surface chemical reactions on perovskite oxides and, by doing so, effectively provide a general synthetic guideline to the design of perovskite-based chemiresistors.

Bioavailability Improvement by Atomic Layer Coating: Fenofibrate A Case Study.

Biopharmaceutical Classification Systems (BCS) class II drugs show poor solubility and high permeability in the body. Fenofibrate (FF) is a classic example of a BCS class II drug, used to treat high cholesterol and triglyceride (fat-like substances) levels in the blood. Atomic layer coating (ALC) is a surface engineering technology adapted from the semiconductor industry, where metal oxides are coated one atomic layer at a time over the active pharmaceutical ingredients (API) particles. ALC coating was proven to improve the processability, alter the hydrophilicity, improve the stability, and fine-tune the release of drugs. Herein, we report the intervention of ALC coating in enhancing the bioavailability of a poorly water-soluble drug (fenofibrate) in the animal model. The physical properties of uncoated fenofibrate were compared with those of zinc oxide-coated and silicon oxide-coated fenofibrate. Following the application of the coatings, the structural integrity (both chemical stability and solid-state stability) of the active pharmaceutical ingredient (API) remained uncompromised, as corroborated by 1H NMR and powder X-ray diffraction analyses. Notably, zinc oxide-coated fenofibrate exhibited favorable flow characteristics, whereas no discernible enhancement in flow behavior was observed for silicon oxide-coated fenofibrate. The results from contact angle measurements suggest that the silicon oxide-coated fenofibrate exhibits superior wetting behavior, as indicated by a contact angle nearing 0°. The application of ALC demonstrates an enhanced dissolution rate when compared to the uncoated active pharmaceutical ingredient (API) while leaving its equilibrium solubility unaffected. Coating the API with silicon oxide improves particle hydrophilicity and wetting properties, whereas zinc oxide coating aids in particle de-agglomeration, thereby enhancing their interaction with an aqueous medium. In vivo bioavailability studies conducted on rodents and larger animal (dog) models indicate a substantial increase in bioavailability (approximately 2 times) for the silicon oxide-coated API in comparison to the uncoated API, as determined by the area under the curve (AUC). Furthermore, the Cmax values for the silicon oxide-coated API also demonstrate a significant increase (approximately 3 times) over the uncoated API. Notably, an oral subacute toxicity study of ALC silicon-coated fenofibrate revealed no toxic effects attributable to the coating. This study underscores the potential of ALC in augmenting the bioavailability of BCS(II) drugs.