Materials Advances最新文献

The rising demand for clean and green energy sources has sparked global interest in sustainable hydrogen production technologies. To address this problem, photocatalytic water splitting has emerged as a promising solution for the sustainable production of green hydrogen and oxygen. We investigate the hydrogen adsorption Gibbs free energy for hydrogen evaluation reaction (HER) and rate-limiting Gibbs free energy for oxygen evolution reaction (OER) to analyse the catalytic activity of the transition metal (TM) intercalated PtXY/ζ-phosphorene (X ≠ Y; X, Y = S, Se, Te) van der Waals heterostructures (vdWHs). Our workflow involves generating a large dataset, followed by performing high-throughput first-principles density functional theory (DFT) calculations on a small fraction of the dataset to obtain the training dataset for a machine learning (ML) framework. Incorporating the ML with the DFT workflow, we obtained 13 potential catalysts for HER and 6 potential catalysts for OER. The interlayer distance of the heterostructures and the bond length between the Pt and X atom emerged as the most influential features for HER, whereas the choice of adsorption site is one of the major OER descriptors. Overall, ML approach integrated with high-throughput first principles calculations is promising for the prediction of potential TM-intercalated vdWHs photocatalysts for water splitting.

Metal-functionalized carbon nanotubes (CNTs) have emerged as versatile nanostructures with tunable properties for energy conversion, storage, and environmental remediation. In this study, we integrate experimental investigations with theoretical modeling to explore the structure–property relationships and multifunctional performance of CNTs decorated with transition metal nanoparticles (Ni, Cu, Ag) and their synergistic combinations (Ni–Cu–Ag). A scalable and facile synthesis route was employed to fabricate these nanocomposites, which were thoroughly characterized to evaluate their structural, morphological, optical, and surface chemical features. The metal-functionalized CNTs demonstrated significant enhancements in oxygen evolution reaction (OER) activity, capacitive energy storage, and photocatalytic degradation of organic pollutants. Notably, the ternary CNT–Ni–Cu–Ag nanocomposite exhibited outstanding OER performance with an overpotential of 382 mV at 50 mA cm⁻² and a Tafel slope of 73 mV dec⁻¹, along with a high specific capacitance of 1451 F g⁻¹ and excellent stability (98% retention after 5000 cycles). Furthermore, the material achieved remarkable photocatalytic degradation efficiencies of ciprofloxacin (98.5%) and diclofenac sodium salt (86%) within 120 minutes under visible light. Complementary density functional theory (DFT) simulations revealed the preferential adsorption of metal nanoparticles on the CNT surface and their role in modulating the electronic band structure, thereby rationalizing the enhanced catalytic and optoelectronic behaviour. These results highlight the promise of metal-functionalized CNTs as multifunctional platforms for next-generation energy conversion, storage, and environmental remediation technologies.

The synthesis and characterization of perylene diimide (PDI) derivatives functionalized by electron donating groups at their bay and imide positions have been reported. Five different PDI derivatives were synthesized and their linear optical and third-order non-linear optical (NLO) properties were studied. The NLO measurements of the synthesized PDI derivatives were conducted under nanosecond (ns) and femtosecond (fs) laser excitation conditions, using the Z-scan technique employing 4 ns, 1064/532 nm and 70 fs, 800/400 nm laser pulses. A noticeable tuning of the NLO character between the synthesized PDI derivatives was observed, revealing the importance of the functionalization of the PDI core by the anchored electron donating units. The largest NLO value was achieved by the incorporation of p-aminoazobenzene at the PDI bay position. The experimental NLO findings and trends were further corroborated with theoretical computations of UV-Vis spectra and NLO response, performed using density functional theory (DFT). It was found that both experiments and simulations satisfactorily convey changes in the NLO response between the studied PDI derivatives. The mechanism that could lead to an efficient tuning of the PDIs' NLO response, is associated with the modification of their electronic character resulting by the proper PDI core functionalization.

When a liquid drop makes first contact with any surface, the unbalanced surface tension force drives the contact line, causing spreading. For Newtonian or weakly elastic, non-Newtonian liquids, either liquid inertia or viscosity, or a combination of the two, resists spreading. In this work, we investigate how drop elasticity influences spreading dynamics. We conduct dynamical experiments with polyacrylamide drops of varying polymer concentrations to impart varying degrees of elasticity. Using high-speed imaging, we focus on the very first moments of spreading on glass substrates. For moderate and high Young's modulus values, we observe that the early-time spreading dynamics obey a viscous-capillary regime characterized by a power-law evolution of the spreading radius. However, the process transitions to a different regime on a timescale comparable to the characteristic viscoelastic relaxation timescale. We interpret this latter regime using a theoretical model invoking the standard linear model of viscoelasticity. For viscoelastic inks with moderate print speeds, the dynamical behavior investigated in this study can provide valuable insights into how to efficiently control such moving contact lines with non-trivial elasticity.

Stimuli-responsive organic materials with dynamically configurable luminescence represent a transformative class of materials with far-reaching implications for next-generation sensing, secure data encryption, and high-performance display technologies. The scope of optical tuning and the ability to precisely modulate emission properties in response to external stimuli offer opportunities for the development of cutting-edge materials that enable breakthroughs in real-time detection, adaptation, and intelligent photonic devices. Focusing on the rational design of luminescent solids, we report three Schiff bases obtained by condensation of hydroxy naphthaldehyde with para-arsenate aniline [1, λ_max 558 nm], ortho-arsenate aniline [2, λ_max 525 nm], and ortho-sulfonate aniline [3, λ_max 535 nm], differing in the position and nature of arsenate and sulfonate functional groups. Anticipated variation of optical properties in the new solid forms is triggered by variation in intra- and intermolecular factors. Structural studies reveal that solid-state emission arises due to the absence of any significant face-to-face π-stacking interactions, while emission tuning is realised through molecular electronic effects generated by functional groups. Multi-stimuli responsive studies carried out for 1–3 indicate the occurrence of crystallization-induced enhanced emission (CIEE) as the emission intensities decline in amorphous grounded forms, the observation further supported by thin film studies. Molecular solids 1 and 3 also exhibit reversible thermofluorochromism, arising due to breathing of lattice water in 3 and phase changes in non-solvated crystals of 1. A non-emissive methanolic solution of 2 exhibits highly selective sensing for Zn(II) ions with an LOD value of 4.9 × 10⁻⁶ M.

In this contribution, we report on the synthesis and characterization of a novel biologically active Cu(II)-based paddle-wheel (PW) metal–organic framework (MOF), RbCu(HCO₂)₂Cl (1). Single-crystal X-ray diffraction results confirmed a monoclinic unit cell with space group P2₁/n and the Rb⁺ cation as a counter-balanced ion located in the cavities of the framework of the dinuclear copper–copper dimer formed by a PW-arrangement of formate anions in the syn–syn configuration. Each Cu(II) atom has a square-pyramidal environment with a Cu⋯Cu intramolecular distance of 2.7070 (7) Å. The IR spectrum confirms the existence of the formate anion (HCO₂⁻). Magnetic susceptibility experiments, performed from 5 to 300 K, revealed a strong antiferromagnetic coupling (J = −531 cm⁻¹) between the two Cu²⁺ ions linked by four formate groups. The powder EPR spectra show the typical lines of the triplet state (S = 1) with significant zero-field splitting, attributed to Cu²⁺–Cu²⁺ dimers. In vitro antibacterial activity was evaluated against two Gram-positive bacteria (Staphylococcus aureus CECT 86 and Listeria monocytogenes CECT 4031) and two Gram-negative bacteria (Escherichia coli CECT 99 and Klebsiella pneumoniae CECT 143^T). The studies revealed that MOF 1 exhibits both bacteriostatic and bactericidal activity against all the microorganisms analyzed, making it a potential candidate for treating bacterial infections. The obtained findings provide more insight into the interesting properties of Cu-based frameworks and antibacterial activity.

This research explores the structural, dielectric, and electrical transport characteristics of polycrystalline La_2−xSr_xFeMnO₆ compounds with varying strontium concentrations (x = 0.0, 0.1, 0.2, 0.5, 1.0, 1.5, and 2.0). These compounds were prepared through the solid-state reaction technique at high temperatures. Rietveld refinement of their XRD data confirms a re-entrant structural phase transition (cubic–rhombohedral–cubic) induced by Sr doping. The vibrational study of (Fe/Mn)O₆ octahedra was carried out by Raman and FTIR spectroscopies. X-ray photoelectron spectroscopy (XPS) results demonstrated the presence of mixed valence oxidation states (+3 and +4) of Fe and Mn cations in the measured samples. The temperature-dependent resistivity data of these compounds have been explained by the long-range electron hopping and short-range polaron hopping conduction mechanisms at high- and low-temperature regions, respectively. Their dielectric constant (ε′) exhibits dispersion behavior, which is attributed to the Maxwell–Wagner interfacial polarization and hopping mechanism of charge carriers. The leakage current density has been explained on the basis of Ohmic conduction mechanism and space-charge-limited conduction (SCLC) mechanism. All these studied properties are strongly influenced by structural distortion-induced strain, oxygen vacancies, Schottky defects, and possible charge ordering. The low leakage current density of these materials with a high dielectric constant make them promising for application in electronic devices.

Lysosomal dysfunction leads to critical lysosomal storage disorder (LSD) conditions, and among all, Mucopolysaccharidosis VII (MPS VII), or Sly syndrome, is a rare LSD caused by the deficiency of the β-glucuronidase (β-GUS) enzyme, leading to the accumulation of glycosaminoglycans (GAGs) in tissues and organs. Since enzyme replacement therapy (ERT) lacks target-specific delivery of recombinant enzymes, targeted enzyme delivery approaches are desired to enhance the success of existing ERT methods. The effective targeted delivery of functional enzymes to lysosomes remains a significant therapeutic challenge. In this study, we report the design and development of a mannose-6-phosphate (M6P) functionalized liposomal nanocarrier for targeted lysosomal delivery of β-GUS. The liposomal nanocarriers were formulated with surface-decorated M6P ligand functionality to exploit the previously established M6P receptor-mediated endocytosis pathway, ensuring high specificity and enhanced intracellular trafficking to lysosomes. Comprehensive physicochemical characterization confirmed the stability, size uniformity, and successful surface functionalization of the liposomes. Internalization studies using HEK293 cells and hemocytes derived from the Drosophila model of MPS VII demonstrated significantly improved cellular internalization and colocalization with lysosomes. The time- and dose-dependent restoration of β-GUS activity was also studied. Furthermore, the nanocarrier exhibited minimal cytotoxicity, indicating its potential for safe and effective ERT. This targeted liposomal system represents a promising platform for lysosome-specific delivery of therapeutic enzymes and could be broadly applied to other lysosomal storage disorders.

Metallic thin-films are found in a wide range of applications, from energy storage to high-power semiconductors used for green energy technologies. Engineering the growth and treatment of metallic thin-films influences their microstructures and residual stress states, which in turn affect their performance and properties. Here, we uncover the influence of tramp elements on the microstructural equilibration in electroplated Cu thin-films during annealing and evaluate the residual stress states in those Cu thin-films. The residual stress gradients within grains of two Cu thin-films, deposited from different electrolytes, are analysed utilising machine learning (ML) based high-resolution electron backscatter diffraction (HR-EBSD). In order to obtain quantitatively comparable stress mappings for both thin-films, simulated stress-free Kikuchi patterns are chosen as common references for HR-EBSD. Despite vastly different grain sizes after identical annealing treatment, similar stress gradients are present within the grains on both thin-film surfaces. The elemental composition at grain boundaries is analysed with atom probe tomography, revealing that S, Cl and O agglomerate in similar concentrations in the ppm-range at grain boundaries of both thin-films. The methodology corroborates that tramp element drag on grain boundaries during annealing may hinder grain growth from the as-deposited nanocrystalline structure, limiting effective stress relaxation and ultimately triggering failure modes.

Herein, we describe the esterification of a polysaccharide-based hydrogel extracted from the sweet basil seeds using citric acid (CA). The formation of CA-crosslinked sweet basil seed hydrogel (CL-SBH) was ascertained through FTIR and solid-state CP/MAS ¹³C NMR spectra. SEM analysis showed the existence of microscopic channels in CL-SBH. The CL-SBH was evaluated for its pH- and saline-dependent swelling properties. The highest swelling of CL-SBH was 17.83 g g⁻¹ in DW and the lowest was 4.21 g g⁻¹ at a pH of 1.2 after 480 min (8 h). During the swelling–deswelling studies, the CL-SBH displayed high swelling capacity in DW and in a buffer with a pH of 7.4, whereas the swelling was negligible in ethanol, normal saline, and in a buffer with a pH of 1.2 upon repeated cycles. Tablets based on CL-SBH and a drug (itopride) were prepared, and the results revealed that the itopride release was prolonged for 4 h at pH levels of 6.8 (97.75%) and 7.4 (94.63%), whereas approximately 36.75% of the drug was released at a pH of 1.2. The itopride release pattern followed first-order kinetics along with a Fickian diffusion mechanism. Acute oral and dermal toxicity studies of CL-SBH were conducted on Swiss albino rats and albino rabbits. The CL-SBH appeared non-toxic and non-irritating, as no change in hematological, biochemical, or histopathological parameters was observed in the animal models. Hence, the CL-SBH is a potential non-toxic material synthesized using a green crosslinking agent for prolonged, pH-dependent, and site-specific drug-delivery applications.