RSC Advances最新文献

We synthesized Co_0.5Mn_0.25Mg_0.25Fe_2−xGd_xO₄ (x = 0.00; 0.04; 0.06) nanoferrites using a sol–gel auto-combustion method and studied their structural, magnetic, and biological properties. XRD with Rietveld refinement confirmed the formation of a pure spinel structure with nanosized crystallites. FTIR and XPS analyses proved the presence of metal–oxygen bonds, mixed oxidation states of Fe and Co, and the successful incorporation of Gd³⁺. TEM images revealed nanometric particles with homogeneous elemental distribution. Magnetic measurements showed that Gd³⁺ doping modifies the saturation magnetization (M_s) and coercivity (H_c), with the best performance at x = 0.04 (M_s = 45.7 emu g⁻¹, H_c = 427 Oe). Under an alternating magnetic field, the samples efficiently produced heat in the hyperthermia range, with a specific absorption rate (SAR) of about 34 W g⁻¹ for x = 0.04. In vivo experiments in ethanol-induced liver injury models demonstrated that the x = 0.04 sample improved antioxidant activity (increased SOD and CAT levels) and restored important serum biochemical markers such as albumin, total protein, creatinine, urea, uric acid, and electrolytes. This indicates strong hepatoprotective and nephroprotective effects. Antibacterial studies further showed that the nanoferrites were more effective against Gram-positive bacteria (S. aureus, B. subtilis, B. licheniformis) than Gram-negative ones (E. coli, P. aeruginosa). Overall, our results show that Gd³⁺ substitution enhances both magnetic and biological properties. The x = 0.04 composition provides the best compromise between magnetic heating efficiency, antioxidant protection, and antibacterial activity, making these nanoferrites promising candidates for biomedical applications such as cancer hyperthermia therapy, antioxidant defense, and infection control.

Industrial dyes are among the most complicated contaminants, posing an increasing hazard to aquatic life if left untreated. Carbon nanoparticles are extremely effective in the adsorption process. As a result, the purpose of this study was to manufacture reduced graphene oxide from sunflower husks, an affordable raw material, and modify its surface with zinc oxide and copper oxide nanoparticles that were produced in an environmentally friendly method. This improved material was employed as a sustainable adsorbent to remove crystal violet and malachite green dyes from wastewater. The results revealed that the optimal medium for adsorption was basic, with an equilibrium time of 25 minutes at 35 °C. Kinetic experiments found that the adsorption follows pseudo-second-order kinetics and is consistent with the Langmuir-Isotherm model. The thermodynamic study showed that the process is spontaneous and endothermic, with increased system randomness. Crystal violet had a removal effectiveness of 95.6%, and malachite green had one of 96% from wastewater.

Bioinspired catalytic systems based on metalloporphyrins have been extensively researched in recent years and, in many cases, have played a key role in the development of more efficient and selective catalysts. The immobilization of this family of catalyst species in robust supports can permit the preparation of recoverable and reusable catalyst solids. In this work, we present the systematic and comprehensive preparation of core@shell-like solids for catalyst immobilization based on magnetic particle, using microwave-assisted synthesis of magnetite, coated with a shell composed of two distinct LDH formulations: Mg₃Al and Ni₃Al, evaluating different LDH/magnetite molar ratios. Four different tetra-anionic metalloporphyrins (Na₄[M(TDFSPP)], M = iron(III), manganese(III), zinc(II), or magnesium(II) ions) (MP) were immobilized in both prepared LDHs. The eight resulting solids were evaluated as catalysts in the model oxidation reaction of cyclooctene to cis-cyclooctene oxide, using iodosylbenzene (PhIO) as the oxidant.

Anisotropic gold nanostructures, such as rods and cubes, exhibit unique optical properties, including absorption in the near-infrared region, which makes them highly attractive for biomedical applications such as imaging and phototherapy. However, conventional synthesis methods often require toxic surfactants and strong reducing agents, limiting their biocompatibility. In this study, we developed a method for synthesizing biocompatible gold nanostructures suitable for photothermal therapy by mineralization using peptides. We designed peptides with different numbers of tryptophan (Trp) residues at N-terminal that can reduce gold ions and control nanoparticle growth. The peptides with fewer Trp residues were found to have a red-shifted maximum absorption wavelength at lower concentrations. A 2 : 1 ratio of gold ions to silver ions was optimal for the formation of anisotropic structures. The peptides successfully imparted high dispersibility to mineralized gold nanostructures. In addition, biocompatibility testing showed no toxicity in mineralized Au nanostructures. We studied the photothermal effect of visible light irradiation on the Au nanostructures, showing that they possessed high biotoxicity under light irradiation conditions. These results suggest that this method can be used for photothermal therapy. Our peptide-based approach offers a simple, safe, and biocompatible strategy to synthesize anisotropic gold nanostructures, which could be applied to the development of future nanomedical tools.

This study presents the fabrication and characterization of 3D-printed biodegradable composite filters for the removal of cationic dyes from aqueous solutions. Inspired by the hierarchical structure of tree leaves, the filters were produced using commercially available polylactic acid (PLA) and a PLA/wood composite filament containing 30% wood dust, via fused deposition modeling (FDM). Post-printing modification was performed by treating the filters with aqueous potassium hydroxide (KOH) solutions at varying concentrations (0.1, 0.2, and 0.4 M). The adsorption behavior was assessed using Crystal Violet (CV) as a model cationic dye at concentrations ranging from 10 to 200 mg L⁻¹ under gravity driven filtration. KOH treatment significantly enhanced the dye adsorption capacity of PLA/wood composite filters, achieving removal efficiencies up to 97.5%. Surface characterization via SEM, FTIR, XRD, and pHpzc analysis confirmed that KOH activation increased surface roughness and introduced functional groups, leading to enhanced electrostatic interaction with cationic species. Moreover, the bioinspired filter geometry with hierarchical porosity contributed to improved mass transfer and dye retention. These findings demonstrate the synergistic effect of material composition, surface modification, and structural design in developing 3D-printed filtration media. The study offers a reproducible and scalable approach for designing polymer-based sorbents for potential applications in water purification.

This study systematically investigates the pyrolysis mechanisms of typical carbohydrates in tobacco under both fast pyrolysis (500 °C) and temperature-programmed conditions (50–500 °C), with a focus on their structural influences on product distributions and reaction pathways. Comparing the fast and temperature-programmed pyrolysis experiments reveals the pyrolysis pathways and product distributions of different structural sugars. Using Py-GC/MS analysis, we demonstrate that small-molecule sugars exhibit distinct pyrolysis behaviors: glucose favors diversified products through 1,2-enolization, while fructose preferentially forms furans via 2,3-enolization due to its ketose configuration. Macromolecular sugars display structure-dependent mechanisms: cellulose yields anhydrosugars through β-1,4-glycosidic cleavage; amylose's α-1,4-linked helical structure enhances anhydrosugar production (62.21%); and xylan's pentose units promote furfural selectivity (46.6%). The Maillard reaction with proline significantly alters pyrolysis pathways, introducing nitrogenous heterocycles and suppressing anhydrosugars while enhancing the ester formation. These findings elucidate the structure–activity relationships governing tobacco carbohydrate pyrolysis, offering a theoretical foundation for optimizing pyrolysis processes and developing functional flavor compounds.

A series of 2′-deoxyribonucleoside 3′-phosphoramidites bearing hydrophobic alkyl-linked modifications at nucleobases was synthesized, namely 5-phenylethyluracil, 5-pentylcytosine, 7-(indol-3-yl)ethyl-7-deazaadenine, and 7-isopentyl-7-deazaguanine derivatives. These nucleoside phosphoramidites were used for solid-phase synthesis of modified and hypermodified oligonucleotides containing up to fifteen modified nucleotides in a row. Their hybridization with complementary non-modified or modified oligonucleotides and thermal stability of the resulting DNA duplexes was studied using UV-vis denaturing experiments and CD spectroscopy. The results indicate that the partially modified hydrophobic DNA can still retain B-conformation, although with lower thermal stability. On the other hand, the hypermodified ONs containing all four modified nucleotides did not hybridize to duplexes likely due to formation of aggregates as indicated by dynamic light scattering measurement. This work expands the toolkit of chemically modified nucleotides for applications in functional nucleic acids or nucleic acid therapeutics, but also shows the scope and limitations of the use of hydrophobic nucleotides in hypermodified oligonucleotides and DNA.

This study aims to optimize the optical and electrical performance of polyvinyl alcohol/polyethylene oxide (PVA/PEO) incorporated with magnesium oxide (MgO) and bismuth(III) oxide (Bi₂O₃) nanoparticles synthesized by pulsed laser ablation over different durations. XRD revealed that the MgO nanoparticles acted as nucleating centers, increasing crystallinity. The incorporation of Bi₂O₃ resulted in sharper peaks and improved phase ordering with a prolonged ablation time. The FTIR spectra showed strong interactions between the PVA/PEO blend and nanoparticles, mediated by hydrogen bonding and novel vibrational modes between the metal and oxygen. UV-DRS showed optical modification and redshift of the absorption edge with a prolonged ablation time, indicating improved nanoparticle homogeneity, size growth, and crystallinity. TGA demonstrated an enhancement in the thermal stability of the Bi₂O₃/MgO double-filler composite. Dielectric and AC conductivity studies demonstrated a frequency behavior consistent with Maxwell–Wagner–Sillars interface polarization. Increasing the ablation time resulted in a decrease in the dielectric constant and conductivity, which was attributed to the small size and good dispersion of the nanoparticles and the restricted charge mobility due to the interface adhesion force.

Carbon-based materials hold significant potential in environmental remediation, as they can effectively remove per- and polyfluoroalkyl substances (PFAS) through adsorption, thereby influencing their environmental behavior and associated risks. However, due to the complexity of the physicochemical properties of carbon-based materials, the molecular diversity of PFAS—including variations in chain length, functional groups, and degree of fluorination—as well as differences in environmental conditions, it remains challenging to fully elucidate the adsorption mechanisms solely through experimental approaches. In this study, a gradient boosting decision tree (GBDT) model was developed and optimized to systematically predict the adsorption performance of carbon-based materials toward PFAS. The GBDT model demonstrated excellent predictive accuracy on the test dataset, achieving an R² of 0.96 and a root mean square error (RMSE) of 0.02. Model interpretation using Shapley additive explanations (SHAP) and partial dependence plots revealed that environmental conditions contributed the most to adsorption, followed by the physicochemical characteristics of carbon-based materials and the molecular features of PFAS. Specifically, solution pH, the number of fluorine atoms within PFAS molecules, temperature, and the pore structure of carbon-based materials were identified as the most influential factors, with electrostatic interactions and hydrophobic–hydrophilic character are likely the dominant mechanisms. This study provides a novel perspective that integrates machine learning with environmental chemistry to enhance understanding of PFAS–carbon interactions, offering valuable insights for environmental risk assessment and the rational design of functional materials.

Developing adsorbents with excellent photothermal and water uptake properties for solar-driven sorption-based atmospheric water harvesting (SAWH) is full of challenging, which requires a balance between the adsorption capacity, hydrophilicity, and photothermal performance of adsorbent. In this work, a LiCl modfiied porous carbon hollow microspheres (CHM@LiCl) adsorbent with high adsorption capacity (2.07 g g⁻¹) at 100% RH and enhanced low moisture adsorption performance was synthesized by loading LiCl hydrophilic adsorption sites into MOFs-derived hollow porous carbon. LiCl, as the main adsorption site, enhances the hydrophilicity of the CHM@LiCl adsorbent, and its water uptake capacity at 20% RH, 40% RH, 60% RH, and 80% RH are 0.25, 0.39, 0.60 and 1.04 g g⁻¹, respectively. In addition, the hiearchical porous structure of the hollow carbon with mciroporus shell effectively suppresses the salt leakage during water adsorption. The sorbent exhibites stable performance for cycling water adsorption-release, indicating its long-term reliability. The excellent photothermal performance of CHM@LiCl adsorbent can quickly heat up to 67 °C under one sun irradiation, and completely desorb the adsorbed water within 30 minutes. The outdoor water harvesting experiment shows that the CHM@LiCl adsorbent holds great potential for practical solar-driven SAWH with a water collection capacity of 3.3 L_water kg_sorbent⁻¹ day under RH 60%.