Journal of Nanoparticle Research最新文献

Layered double hydroxides (LDH) with MgAl and ZnAl cation combination are well-known as drug-delivery vehicles. Aluminum provides structural stability enabling the intercalation and functionalization of materials to produce multifunctional materials for biomedical applications. However, aluminum is not desirable as it is a possible promoter of neurodegenerative diseases. In this work, we explore some procedures to obtain aluminum-free LDH composed of MgFe, additionally including Gd(III) and Dy(III) cations. The resulting medium-entropy material was further functionalized with doxorubicin (Dox), a chemotherapeutic drug, and trastuzumab (Tzmb), an antibody used to confer selectivity to breast cancer cells. The stability of the medium-entropy structure was assessed against the functionalization processes by X-ray diffraction (XRD), infrared spectroscopy (FTIR), and the Z-potential technique. Finally, the functionalized particles served as magnetic resonance imaging (MRI) contrast agents, demonstrating the potential of MgFeGdDy LDH as theranostic particles.

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The quest for high-performance energy storage materials has led to the exploration of a novel binary nanocomposite composed of vanadium hexacyanoferrate (VHCF) and polymethyl methacrylate (PMMA). The synthesized VHCF-PMMA nanocomposites were fabricated as working electrodes in various stoichiometric ratios (50:50, 70:30, and 80:20) for supercapacitors. The effective encapsulation of VHCF within the PMMA matrix was confirmed through FESEM, HRTEM, and XRD analyses. BET analysis reported an impressive surface area of 356.35 m²/g and an average pore size of 2.92 nm for the VHCF-PMMA nanocomposite. The electrochemical properties of the VHCF-PMMA electrodes were investigated in a three-electrode assembly (0–0.5 V working voltage window) using 1 M KOH electrolyte. From CV profile, VHCF-PMMA (80:20) electrode demonstrated the highest specific capacitance (575 F/g at 10 mV/s) in comparison to 70:30 (274 F/g) and 50:50 (188 F/g) electrode compositions. GCD analysis of the VHCF-PMMA (80:20) electrode also displayed the highest specific capacitance (455 F/g at 0.5 A/g) with minimal IR drop. Significant capacitive retention of 72.1% was exhibited by the optimized VHCF-PMMA electrode even after 5000 cycles. Further, the symmetric supercapacitor fabricated using the optimized electrodes yielded a specific capacitance of 119.06 F/g (0.5 A/g) with 66.5% capacitive retention and stable coulombic efficiency after the completion of 5000 cycles. The fabricated device delivered the maximum energy density of 23.56 Wh/Kg at a power density of 299.95 W/Kg (0.5 A/g) and exhibited a high power density of 3015 W/Kg at the energy density of 8.04 Wh/Kg (5 A/g). Hence, the current research is a demonstration of an increase in the structural and electrochemical properties of VHCF due to the mechanical integrity provided by PMMA in the novel VHCF-PMMA combination for its effective usage in supercapacitors.

Using density-functional theory calculations, we present a comprehensive investigation of the structural and magneto-electronic properties of CoPt dimers adsorbed on nitrogen-doped divacancies (NDVs) in graphene under applied electric fields. Our study focuses on the microscopic mechanisms governing structural stability, electronic hybridization, and magnetic anisotropy, emphasizing how the combined effects of NDVs and electric fields tune the magnetic response of the CoPt/graphene hybrid system. Our results reveal that NDVs, together with external electric fields, create a chemically active defect landscape that strongly modulates dimer adsorption and bonding behavior. This interplay enhances charge transfer and orbital polarization, resulting in pronounced variations of the magnetic anisotropy energy (MAE). The CoPt dimer exhibits a nearly fourfold increase in binding stability compared to adsorption on pristine graphene, facilitated by partial embedding within the NDV site. Moreover, beyond the intrinsic Co–Pt dipole, four additional local dipoles emerge between Co and the neighboring nitrogen atoms due to charge transfer from Co to N, significantly modifying the effective permanent dipole moment of the composite system. The total magnetic anisotropy originates from two distinct yet coupled contributions: (i) the magnetocrystalline term, (mathrm {MAE_{SOC}}), primarily associated with spin–orbit coupling (SOC) on the Pt atom, and (ii) the structural term, (mathrm {MAE_{str}}), induced by electric-field-driven lattice distortions. Their interplay determines the overall effective anisotropy and the direction of the easy magnetization axis. A microscopic analysis of the magnetocrystalline anisotropy, based on the local density of states (LDOS) of the CoPt dimer, demonstrates that (mathrm {MAE_{str}}) correlates with orbital anisotropy in agreement with Bruno’s relation. The preferred magnetization direction is further rationalized through the symmetry of the d-orbitals near the Fermi level and their dominant couplings mediated by the orbital angular momentum operators (hat{L}).

We present a density functional theory (DFT) investigation of vanadium-doped platinum cluster anions, Pt(_{n})V(^{-}) ((n = 1)–13), focusing on their size-dependent structural, energetic, and electronic properties. Global optimization using a Basin Hopping approach reveals a transition from planar or quasi-planar low-symmetry structures at small sizes to compact, highly coordinated three-dimensional motifs as the Pt content increases. Energetic descriptors, including binding energies, second-order energy differences, and HOMO–LUMO gaps, identify (n = 3), 5, and 10 as particularly stable cluster sizes. These enhanced stabilities arise from distinct bonding regimes, with strong Pt–V interactions dominating at small sizes and increasing Pt–Pt metallic bonding and electronic delocalization stabilizing larger clusters. A highly symmetric (C_{3v}) pyramidal structure is identified as the global minimum for Pt(_{10})V(^{-}), highlighting the stabilizing role of symmetry. Bond-length and Hirshfeld charge analyses reveal nearly constant Pt–V distances and significant charge transfer from V to Pt in small clusters, followed by increased delocalization and bulk-like Pt–Pt bonding with size. Density of states calculations further confirm the crossover from molecule-like to metallic electronic behavior. Overall, these results elucidate fundamental structure–property relationships in Pt(_n)V(^{-}) clusters, relevant for the rational design of V-doped platinum nanoalloys.

Aflatoxin B₁ (AFB₁) is one of the most toxic and prevalent mycotoxins in poultry feed, posing serious risks to animal health and food safety. In this study, fluorinated silica nanoparticles (F-SiO₂NPs) were synthesized via a modified Stöber sol–gel method and evaluated as adsorbents for AFB₁ using a dynamic in vitro poultry gastrointestinal model. Comprehensive structural and surface characterization using multiple complementary techniques confirmed the formation of spherical, amorphous silica nanoparticles (SiO₂NPs) and the successful grafting of fluorinated moieties, which significantly increased surface hydrophobicity. Adsorption experiments were conducted at two nanoparticle dosages (0.1 and 1%, w/v) in an in vitro model that simulates poultry crop, proventriculus, and intestinal conditions, including the replication of chemical and enzymatic factors, as well as feed presence and residence time. In the last simulated compartment of the model (intestine), at 0.1% (w/v), pristine SiO₂NPs showed limited AFB₁ adsorption (5.3%), whereas F-SiO₂NPs exhibited a substantially higher removal efficiency (29.9%). At 1% (w/v), adsorption efficiencies increased to 62.2% for SiO₂NPs and 78.7% for F-SiO₂NPs. AFB₁ adsorption was governed by a combination of hydrogen bonding, dipole–dipole interactions, pore structure effects, and enhanced hydrophobic and van der Waals interactions induced by fluorination. These results demonstrate that F-SiO₂NPs are promising candidates for improving AFB₁ adsorption under physiologically relevant digestive conditions.

In this study, a Z-scheme heterojunction photocatalyst was successfully synthesized via a hydrothermal approach by coupling protonated g-C₃N₄ derived from hydrochloric acid modification with the solid solution BiOI_0.8Br_0.2. The as-prepared material was systematically characterized using XRD, FT-IR, SEM, HRTEM, XPS, PL, and photoelectrochemical measurements to evaluate its crystalline structure, surface morphology, elemental chemical states, defect features, and optical as well as photoelectrochemical properties. HRTEM analysis revealed a nanoflower-like architecture in which ultrathin g-C₃N₄ nanosheets were uniformly anchored onto the surface of BiOI_0.8Br_0.2 nanoflowers, facilitating intimate interfacial contact between the two components. Electrochemical impedance spectroscopy and transient photocurrent response measurements demonstrated a marked reduction in interfacial resistance and a significant increase in current density, indicating enhanced charge transfer efficiency at the heterojunction interface and promoting effective separation and rapid migration of photogenerated electron–hole pairs. Under the Z-scheme charge transfer mechanism, electrons from the conduction band of BiOI_0.8Br_0.2 recombine with holes from the valence band of g-C₃N₄ at the interface, thereby preserving highly reductive electrons in the g-C₃N₄ component and highly oxidative holes in BiOI_0.8Br_0.2. This spatial charge separation significantly enhances the redox capability of the system. Consequently, the resulting photocatalyst exhibited outstanding degradation performance toward RhB and ENR under light irradiation, with high efficiency and excellent stability. Furthermore, recycling experiments confirmed that the catalyst retained high activity and structural integrity over multiple cycles, underscoring its robustness and potential for practical applications in environmental remediation.

The development of efficient photocatalyst heterogeneous junctions has become a major focus of research for removing microbial pollution. In the current work, we assembled I-doped g-C₃N₄ decorated with AgI (AgI/ICN) heterostructures (with different AgI ratios (from 10 to 40 wt%), to achieve high visible light–based photocatalytic disinfection efficiency toward Staphylococcus aureus (S. aureus). Under visible illumination, the optimum 20wt%-AgI/ICN hybrid achieved complete inactivation efficiency, almost 10-, 8-, and 5-times greater than that of undoped CN, ICN, and AgI, respectively. I-doping enlarges the CN response in the visible light region, while the type II heterojunction developed between ICN and AgI leads to an effective separation of charge-carriers. According to the trapping tests, the key reactive oxygen species (ROS) inactivating S. aureus were ^•O₂⁻ and h⁺, which approves the suggested mechanism.

The present study aims to develop a new preconcentration strategy for the determination of non-essential cadmium ions in red onion samples. Determination of the extracted cadmium ions was carried out using flame atomic absorption spectrometry for efficient and sensitive detection. The synthesis of CuSn(OH)₆ nanoparticles was accomplished via a single-step one-pot coprecipitation method under ambient conditions to obtain nanoparticles below 100 nm in size, which are particularly effective for preconcentration procedures. The morphology and structure of the nanoparticles were confirmed with different characterization techniques. Under the optimized conditions, the calibration curve of the presented method showed good linearity between 2.5 and 50 μg/L, with a detection limit of 0.84 μg/L. The accuracy of this method was confirmed by obtaining recoveries of spiked red onion extracts. This method offers a sensitive, efficient, and eco-friendly method for the separation/detection of trace cadmium ions in aqueous plant-derived matrixes, especially red onion extracts.

This study examines effects of In³⁺ on the thermal, structural, cationic, Raman, morphological, and optical properties of sol–gel auto-combusted Ni_0.65Zn_0.35Fe_2-xIn_ₓO₄ (x = 0.00, 0.08, 0.16, and 0.24) nanoparticles. X-ray diffraction (XRD) confirmed the formation of single-phase cubic spinel structure, with an enhanced lattice parameter attributed to the larger ionic radius of In³⁺. In the cation distribution derived from the XRD data, at lower concentrations In³⁺ primarily occupied tetrahedral sites, whereas at higher concentrations (x ≥ 0.16), it distributed over both tetrahedral and octahedral sites. Raman spectra revealed consistent vibrational modes that remained intact even with In³⁺ doping. Field-emission scanning electron microscopy (FE-SEM) demonstrated spherical grains with few agglomerations, whereas transmission electron microscopy (TEM) indicated a decrease in the average particle size from 25.4 nm to 17.9 nm with In³⁺ doping. The selected area electron diffraction (SAED) pattern validated the polycrystalline nature by the presence of concentric diffraction rings corresponding to the allowed crystal planes of the cubic structure. X-ray photoelectron spectroscopy (XPS) provided the oxidation states and changes in the chemical environment of the elements in the composition. Moreover, diffuse reflectance spectroscopy (DRS) revealed an enhanced optical band gap with In³⁺ varying in the range of 2.23–2.56 eV. Additionally, the photoluminescence (PL) spectra exhibited a wide emission band suggesting the presence of multiple sub-bands, indicating numerous energy levels. The photocatalytic degradation of four dyes, namely, congo red, rhodamine B, methylene blue, and crystal violet, was studied under visible light. The highest efficiency (72.3%) for methylene blue degradation over 180 min was shown by the 10-mg catalyst dosage of sample x = 0.16.

This study aimed to synthesize hollow silica nanoparticles (HSSN) using the hard template based on recycled polystyrene (PS) with the presence of various amounts of cationic surfactant of cetyltrimethylammonium bromide (CTAB). The results of PS nanoparticle size and poly dispersity index determined by dynamic light scattering (DLS) showed that changing CTAB concentration had little effect. Increasing PS material concentration resulted in a gradual increase in nanoparticle distribution and size, with an average value from 191 to 423 nm. A high concentration of CTAB increased the zeta potential of the nano PS solution with values ranging from 61 to 85 mV. The highly positive zeta potential could ensure stability of the PS nanoparticle. In addition, the positive charge on the template could also facilitate the silica deposition on the PS surfaces. Transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy measurement results confirm that HSSN particles were successfully fabricated. CTAB could significantly improve the methylene blue (MB) adsorption capacity from 6.7 to 17.5 mg/g. Mesoporous structures could be detected and the surface area of HSSN could increase up to 325 m²/g by adding more CTAB to the PS template solution. However, the materials were incapable of loading KMnO₄. CTAB played another role in altering the surface charge of HSSN and gave rise to KMnO₄ adsorption. The KMnO₄-loaded-HSSN with balanced macro- and mesopores could provide a decrease in ethylene gas production during the ripening process of the banana. The result showed that the current materials could be potentially applied to fruit storage technologies.

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