Journal of Nanoparticle Research最新文献

Optimizing TiO₂ nanotube/nanoring (NT/NR-TiO₂) systems with graphene derivatives is a powerful strategy to enhance solar-driven water treatment, yet their performance under aggressive acidic conditions remains underexplored. This study evaluates the synthesis, interfacial properties, and artificial solar-driven methylene blue (MB) degradation of GO- and rGO-modified NT/NR-TiO₂ architectures. SEM and XRD confirmed well-defined, highly crystalline anatase arrays. The average crystallite size from the anatase (101) reflection was 20.36 nm for pristine NT/NR-TiO₂, decreasing to 17.42 nm and 18.64 nm for GO and rGO modifications, respectively. Photoelectrochemical profiles and Mott-Schottky analysis revealed that the NT/NR-TiO₂-GO composite achieved the highest photocurrent response. This performance was driven by an optimized potential drop, suppressed electron-hole recombination, and strong π-π surface interactions under extreme acidic conditions (pH 1). Consequently, the GO-modified photoanode delivered a superior MB degradation efficiency of 85% within 120 min (k_app = 1.53 × 10^–2 min⁻¹), outperforming both rGO-modified and pristine counterparts. Importantly, this was accompanied by a 78.6% reduction in chemical oxygen demand, demonstrating extensive partial oxidation into lower-molecular-weight fragments. Furthermore, the composite displayed robust operational reusability, retaining 80% efficiency after 5 consecutive cycles (600 min total). These findings confirm its high stability and potential for the direct treatment of acidic industrial effluents without preliminary neutralization steps.

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Magnetic nanoparticles were successfully modified with a thin layer of molecularly imprinted polymers (MIPs) via the admicellar polymerization technique for the selective removal of methylene blue (MB) from real water samples. The chemical and morphological properties of the synthesized materials were comprehensively characterized using Fourier Transform Infrared Spectroscopy–Attenuated Total Reflectance (FTIR–ATR), X-ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM). The adsorption kinetics were better described by the pseudo-second-order kinetic model (R² > 0.99), indicating that the adsorption process was mainly governed by chemical interactions. The maximum binding capacity of the MB-imprinted polymer-modified magnetic nanoparticles was determined to be 5.64 mg g⁻¹ (95% CI: 6.76–4.52 mg g⁻¹). Equilibrium adsorption data showed a better fit to the Freundlich isotherm model (R² > 0.99), suggesting heterogeneous adsorption behaviour, which is characteristic of molecularly imprinted systems. The prepared adsorbent exhibited excellent reusability and maintained its adsorption performance over seven consecutive adsorption–desorption cycles without significant efficiency loss. The imprinting factor for MB was calculated as 7.18, while lower values were obtained for methylene violet (3.11) and indigo carmine (1.97), demonstrating the high selectivity of the imprinted cavities toward the template molecule. Moreover, the selectivity coefficients (k) for methylene violet (2.41) and indigo carmine (3.18) confirmed the preferential recognition of MB over competing dye molecules. The optimum adsorption conditions were determined as pH 7 and an incubation time of 35 min. The applicability of the developed MIP-based magnetic adsorbent was further validated using real water samples collected from different natural sources. The findings highlight the novelty and potential of the proposed system as a selective, reusable, and efficient adsorbent for wastewater treatment applications.

This study investigated the effect of glycine concentration on the physicochemical properties of zero-valent iron nanoparticles (NPs-Fe) synthesized by chemical reduction. XRD results showed that Fe⁰ with a body-centered cubic (BCC) structure remained the predominant crystalline phase after functionalization, while the crystallite size decreased progressively from 9.55 to 5.54 nm as the glycine concentration increased. In contrast, SEM analysis showed an increase in the average particle diameter from 58.95 ± 12.80 nm for NPs -Fe to 75.51 ± 18.30, 83.36 ± 27.60, and 83.79 ± 29.50 nm for NPs-FeG1, NPs-FeG2, and NPs-FeG3, respectively. Chain-like structures were observed in all samples; their formation may be associated with dipole–dipole magnetic interactions and surface interactions between the nanoparticles. The FTIR results were consistent with the interaction of glycine with the surface of the NPs-Fe and with the presence of surface species of iron oxides and oxyhydroxides. The effect of glycine on the zeta potential depended on its concentration; NPs-Fe-G1 exhibited the highest absolute value, while higher concentrations did not produce any further improvement in colloidal stability. TGA/DSC thermogravimetric analyses showed that glycine modifies the thermal behavior of the nanoparticles, while Raman analysis of the thermally treated residues revealed the presence of iron oxide and iron oxyhydroxide species. Overall, the results show that the glycine concentration influences the growth of crystallites, particle size and morphology, surface characteristics, colloidal behavior, and thermal response, without altering the BCC structure of Fe⁰. These results contribute to our understanding of the effect of glycine as a surface modifier of zero-valent iron nanoparticles and provide a foundation for further studies in areas such as environmental remediation, catalysis, detection, and biomedical applications.

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Surface reflection reduces the amount of light reaching the solar cell and can lower its photovoltaic performance. Therefore, antireflection coatings are important for reducing optical losses and improving the solar cell performance. In this study, ZnO/PMMA films were coated on the cover glass of the solar cell using a sol-gel dip-coating technique. PMMA was added to the ZnO matrix as a porogen to form porous ZnO films. The effect of PMMA concentration in the dip-coating solution on optical properties, crystal and chemical structure, and photovoltaic conversion efficiency was investigated. XRD and FTIR analyses proved that ZnO was successfully obtained both alone and in the presence of PMMA. In addition, FESEM and optical microscopy images revealed that the pores on the surface were observed to increase as the PMMA content of the ZnO/PMMA film increased. ZnO/PMMA coated glass slides exhibited higher transmittance, lower reflectance and refractive index values in the visible wavelength range compared to pure ZnO coated glass slides. Among the investigated samples, the film containing 3 wt.% PMMA exhibited the most favorable combination of optical and photovoltaic properties. The UV-Vis spectrum showed a maximum transmittance of 92.50%, a lowest reflectance of 6.35% and a lowest refractive index value of 1.64 at a wavelength of 650 nm with the PMMA/ZnO film containing 3 wt.% PMMA on a glass slide. Adding the PMMA phase to the ZnO film resulted in approximately a 6% increase in solar cell efficiency. The pore formation mechanism of PMMA could be attributed to the aforementioned improvement in the light transmittance and photovoltaic conversion efficiency. The present findings demonstrated that the addition of PMMA provided a simple solution-based route to modify the porosity, refractive index, optical transmittance/reflectance, and photovoltaic performance of ZnO films. Therefore, ZnO/PMMA coatings might represent a promising alternative approach for antireflection applications in silicon solar cells.

The prevalence of antimicrobial resistance has intensified the need for alternative approaches to overcome the limitations of conventional drugs. Photodynamic inactivation (PDI), in which photosensitizers (PSs) generate reactive oxygen species upon light activation, has emerged as a promising strategy by inducing multi-target microbial damage. Nevertheless, low water solubility, aggregation, and limited performance of many molecular PSs, especially in complex environments such as biofilms, can reduce PDI efficacy. This review examines applications of inorganic nanoparticles (iNPs) in the PDI of bacteria and fungi, integrating fundamental principles, physicochemical properties, and biological interactions with PDI outcomes. Illustrative examples include silver nanoparticles associated with Zn(II) porphyrins, which enabled PDI-mediated eradication of Candida albicans at ~ 4- to 8-fold lower PS concentrations, whereas the PS alone caused a reduction of ~ 2–3 log₁₀, and a silica-based platform that decreased Rose Bengal dark toxicity in Escherichia coli, increasing viability from ~ 43 to 83–99%. Conversely, Ag-doped TiO₂ induced ~ 30% C. albicans reduction even without irradiation, indicating light-independent antimicrobial activity. These and other examples are reported in the review, which shows that iNPs can broaden the scope of PDI applications through distinct and complementary mechanisms. Challenges, however, remain, such as variability in experimental parameters and data reporting, which may limit the interpretation of reported outcomes, along with limited fungal model diversity and incomplete mechanistic understanding, important aspects for clinical translation. Overall, this review outlines advances and challenges in the field, providing insights to guide the development of improved iNP-based platforms for antimicrobial photodynamic applications.

Graphitic carbon nitride (g-C₃N₄), a promising photocatalyst, holds wide applications in sulfate radical (SO₄^•⁻)-based advanced oxidation processes. Unfortunately, its practical utilization is still restricted by poor conductivity and severe recombination of photogenerated charge carriers. Herein, a two-step calcination strategy is put forward to boost the photocatalytic performance by constructing CN/BCN homojunction, where CN refers to the urea-based g-C₃N₄ and BCN denotes the melamine-derived boron-doped g-C₃N₄ with two-step calcination. Boron doping endows BCN with narrowed band gap and red-shifted light absorption edge. Meanwhile, the CN/BCN homojunction achieves low electrochemical impedance, optimal photocurrent response, and appropriate charge carriers capture capability. Tetracycline (TC) removal efficiency reaches 98.6% by CN/BCN accompanied with potassium persulfate (K₂S₂O₈) under visible light irradiation for 60 min, along with the corresponding kinetic rate constant being 0.0748 min⁻¹. Over five consecutive cycling tests, TC removal efficiency stays still higher than 90.0%. In addition, the common coexisting anions exert minor effect on its photocatalytic performance. As for the persulfate-based CN/BCN photocatalytic system, SO₄^•−, ^•OH, ^•O₂⁻ and photogenerated holes (h⁺) all serve as active radicals for TC removal, with their relative contribution levels as SO₄^•− < ^•OH < ^•O₂⁻ < h⁺.

Lead halide perovskite nanocrystals (PeNCs) are solution-processable materials possessing excellent optical properties that can be exploited for a wide range of optoelectronic applications. However, the colloidal stability of PeNCs remains a practical challenge, and PeNC aggregation during post-synthetic processing or storage hinders subsequent dispersion and material recovery. Ligand engineering and other chemical stabilization strategies have been widely developed to improve PeNC stability; however, the redispersion of already aggregated PeNCs without intentional ligand modification remains underexplored. Herein, we investigate rotor–stator processing as a mechanical approach for redispersing aggregated formamidinium lead bromide (FAPbBr₃) nanocrystals and compare its performance with that of ultrasonic treatment and vortex mixing. Under a fixed 30 s processing protocol, rotor–stator treatment increased the fraction of Pb-containing PeNC material remaining in the supernatant after standardized centrifugation while largely retaining the measured optical and photophysical characteristics. In methylcyclohexane (MCH), the Pb-based colloidally stable recovery yield reached 58.13 ± 4.08%, compared with 18.35 ± 1.88% after ultrasonic treatment under matched solvent, sample volume, treatment time, and post-treatment centrifugation conditions. The Pb detected in the recovered supernatant is expected to originate predominantly from the Pb-containing PeNC material after the removal of soluble reaction components during the initial purification step. After 31 days of storage, the rotor–stator-processed MCH dispersion retained 84% of its initial nanocrystal concentration and 96% of its initial photoluminescence quantum yield. These results demonstrate that rotor–stator processing can provide a mechanical route for recovering colloidally suspended material from aggregated PeNC dispersions without intentional ligand exchange or additional ligand addition.

The targeted photodegradation of persistent antibiotics in complex environmental water matrices and the enhancement of charge separation efficiency are key objectives in photocatalytic research, yet traditional materials often face limitations in both selectivity and carrier dynamics. To address these challenges, a molecularly imprinted BiFeO₃ (I-BFO) catalyst was fabricated via a molecular imprinting strategy. Relative to pristine BiFeO₃ (BFO), the I-BFO catalyst achieved a 2.52-fold increase in the degradation rate of ciprofloxacin (CIP). In competitive degradation tests, I-BFO exhibited preferential degradation of CIP over tetracycline (TC), with a selectivity coefficient (K) of 1.79 relative to BFO, indicating enhanced recognition specificity toward the template molecule. The I-BFO catalyst retained approximately 90.0% of its initial degradation efficiency after five successive cycles, demonstrating ideal stability and reusability. Radical scavenging experiments revealed that photogenerated holes (h⁺) and hydroxyl radicals (•OH) are the primary reactive species governing CIP degradation. Overall, this work provides an experimental foundation for the selective removal of antibiotics from wastewater and contributes to the development of advanced photocatalytic materials for environmental remediation.

A single-source precursor approach has been utilized for the preparation of lead sulfide nanoparticles with various phases, sizes, and shapes, using lead(II) dithiocarbamate complexes. Three new precursor complexes bis(N-hexyl-N-(1H-indole-3-yl-methyl)dithiocarbamato-S,S’)lead(II) (1), bis(N-dodecyl-N-(4-dimethylaminobenzyl)dithiocarbamato-S,S’)lead(II) (2) and bis(N-(2,4-dichlorobenzyl)-N-(2-phenylethyl))dithiocarbamato-S,S’)lead(II) (3) have been prepared and characterized using infrared (IR), Nuclear magnetic resonance (NMR) (¹H and ¹³C) spectroscopy and elemental analysis. IR and NMR spectral studies of complexes 1–3 confirmed that the dithiocarbamate ligands coordinate in a bidentate manner through the sulfur atoms. The decomposition of complexes 1–3 using the reflux method, in the presence of ethylenediamine as a capping agent, yielded single-phase PbS nanoparticles. Lead sulfides prepared from complexes 1–3 are represented as PbS-1, PbS-2 and PbS-3, respectively. The crystalline phase of the nanoparticles was established to be face-centered cubic structure. The optical properties and the morphology of the as-prepared nanoparticles were studied by ultraviolet–visible diffused reflectance spectroscopy (UV-DRS) and field emission scanning electron microscopy (FESEM), respectively. FESEM analysis shows that the N-bound organic moiety in complexes 1–3 significantly influences the morphology of lead sulfide nanoparticles. The photocatalytic activities of lead sulfides were evaluated through the photodegradation of an aqueous solution of methylene blue (MB) under UV irradiation. Among the three PbS catalysts (PbS-1, PbS-2 and PbS-3), PbS-3 exhibited higher degradation efficiency (92%) against MB dye. The effect of different parameters such as pH, initial dye concentration and photocatalytic dose was examined. The nanocatalysts exhibited good recyclability over four cycles. Radical scavenger experiments indicated that hydroxyl radicals (^•OH) acted as the dominant reactive species for dye degradation.

Chrysanthemum-like Co₃O₄ microstructures were synthesized via a hydrothermal method followed by calcination and subsequently modified with Ag- and Ni-containing surface species. The structural, morphological, surface chemical, and optical properties of the prepared materials were characterized using SEM–EDS, TEM, XRD, FTIR, XPS, and UV–Vis spectroscopy. XRD analysis confirmed cubic spinel Co₃O₄ as the predominant crystalline cobalt oxide phase, while SEM and TEM observations showed that the hierarchical chrysanthemum-like morphology was largely retained after surface modification. EDS and XPS analyses confirmed the presence of Ag- and Ni-containing species on the corresponding modified Co₃O₄ surfaces. The catalytic performance of the electrodes was comparatively evaluated under electrocatalytic (EC), photocatalytic (PC), and photoelectrocatalytic (PEC) conditions using methyl orange (MO) as a model pollutant. Under PEC conditions, pristine Co₃O₄, Ni-modified Co₃O₄, and Ag-modified Co₃O₄ achieved MO removal efficiencies of approximately 61.0%, 67.5%, and 77.5%, respectively, after 120 min. Among the investigated electrodes, the Ag-modified Co₃O₄ electrode exhibited the highest PEC performance. Although surface modification resulted in changes in the optical response, the enhanced PEC activity cannot be attributed solely to variations in light absorption or apparent optical transition energy. Overall, modification with Ag-containing surface species effectively enhanced the PEC performance of chrysanthemum-like Co₃O₄ under the investigated conditions.