Journal of Nanoparticle Research最新文献

In this work, CaS phosphors were synthesized using the sol–gel method with doping of rare earth metals such as Eu, Dy, and Tm in combination. The optimization of the dopant concentration at 2% allowed for the adjustment of the samples’ characteristics. Detailed analyses were carried out, including X-ray diffraction studies, evaluation of photoluminescence characteristics, examination of hemocompatibility, and determination of the average lifetime of the excited state for this novel set of CaS phosphors. The synthesized phosphors displayed intense greenish-yellow emissions at a wavelength of 543 nm, which can be attributed to the electric dipole transition resulting from the dopants. Among the different compositions, the CaS phosphors doped with 2% Eu and 2% Dy showed exceptional structural and morphological qualities. Additionally, this composition exhibited the highest hemolysis inhibition percentage, with 82.37% of red blood cells remaining viable. Moreover, this particular sample demonstrated the maximum light efficacy in terms of radiation and excitation purity. The study emphasizes the luminescent properties and biocompatibility of the CaS phosphor, particularly when enhanced through doping. The findings suggest promising potential for the application of these phosphors in the field of bioimaging.

Oxygen reduction reaction (ORR) is an important reaction process that occurs at the cathode of zinc-air batteries. An efficient reaction process is conducive to further research on sustainable energy devices. In order to improve the reaction speed, the ORR electrocatalyst containing uniform Fe–N-C sites in a porous carbon network similar to the shape of moth-eaten rotten wood was prepared using water hyacinth with a thin-layer structure inside as a template. Water hyacinth, plays a variety of synthetic functions in the construction of nanocatalysts, not only has a good enrichment effect on metal elements, but also is rich in N element. The doped Fe elements combine with the carbon and N elements of water hyacinth to form Fe–N-C active sites. The half-wave potential of SHL-Fe-HMNC is raised to 0.881 V (0.838 V for commercial 20wt% Pt/C) compared to the reversible hydrogen electrode (RHE). The power density of the liquid battery prepared based on SHL-Fe-HMNC reaches 110 mW·cm⁻² (90 mW·cm⁻² for 20 wt% Pt/C). Furthermore, the cycle time of ZABs exceeds 200 h. The flexible battery based on SHL-Fe-HMNC has a cycle stability of more than 10 h at a current of 10 mA·cm⁻², and the open circuit voltage (OCV) reaches 1.511 V.

Graphical Abstract

Zeolite-based core–shell adsorbents are a promising new technology for removing toxic pollutants from aquatic environments. These adsorbents have a core of zeolite, a porous material with high adsorption capacity and selectivity. The outer shell of the adsorbent is made of another material, such as polymer, activated carbon, or metal. This structure provides several advantages, such as increased adsorption capacity, selectivity, and adsorbent stability. Zeolite-based core–shell adsorbents have shown great potential to remove toxic pollutants from aquatic environments, such as azo dye, heavy metals, and pharmaceuticals. However, there are still some challenges in the research and development of these adsorbents, such as developing simple and economical synthesis methods, improving adsorbent stability under different water conditions, and developing adsorbents that can remove multiple toxic pollutants simultaneously. Despite these challenges, zeolite-based core–shell adsorbents are a promising technology for removing toxic pollutants from aquatic environments. These adsorbents have the potential to provide an effective and economical solution to this serious environmental problem.

This paper investigates the effect of three different alkalis, namely ammonia (NH₄OH), ethylenediamine (EDA), and tetrabutylammonium hydroxide (TBAOH) on the stability of colloidal silica, with pH controlled within the range of 8–11. As a result, NH₄OH greatly promotes the stability of silica sol at first due to the strong solvation ability of NH₄⁺ and then the stability begins to decrease because the electric double layer of silica is compressed. The addition of EDA into silica system leads to a reduction in the stability evidently followed by a slight increase, which can be explained by the cationic bridging effect of the ethylenediammonium cations. Meanwhile, the effect of TBAOH on silica dispersion is analogous to EDA, mainly caused by the hydrophobic and steric effects. The abovementioned relevant stability mechanisms are involved in non-DLVO theory.

The objective of the study is to prepare quaternized chitosan magnetic nanoparticles (ICG@Fe₃O₄@QCS) loaded with indocyanine green and to investigate their properties. Fe₃O₄@QCS nanoparticles were prepared by a one-part precipitation method and evaluated for their structure, particle size, morphology, and magnetic responsiveness. ICG@Fe₃O₄@QCS nanoparticles were prepared by electrostatic adsorption to investigate the properties of ICG@Fe₃O₄@QCS nanoparticles, such as particle size, zeta potential, encapsulation rate, drug loading, stability, photo- and thermo-conversion efficiencies, degree of release, biosafety, and in vitro antitumor property. Fe₃O₄@QCS nanoparticles were successfully prepared in the form of short rods with particle sizes around 20–30 nm, positively charged, with basic Fe₃O₄ skeleton, and possessing specific magnetic responsiveness. ICG@Fe₃O₄@QCS nanoparticles were successfully prepared, particle size is around 100–150 nm, charged positively, the encapsulation rate is ≥ 90%, the drug loading is 0.05–2.00%, the release is slower compared with the ICG solution, and hemolysis rate is less than 2% in all cases; in the laser irradiation, the nanoparticles can produce ROS and thermal effects and have the function of NIR imaging. Antitumor experiments in vitro showed that ICG@Fe₃O₄@QCS nanoparticles had strong phototoxicity, had a particular killing effect on tumor cells, and could promote Hela cell apoptosis. ICG@Fe₃O₄@QCS nanoparticles can be successfully prepared by the electrostatic adsorption method, with the stable nature of ICG@Fe₃O₄@QCS nanoparticles, which can improve the bioavailability of ICG, and the prepared nanoparticles have good antitumor properties.

Vanadium has various oxidation states and multiple crystalline phases that make it interesting for various applications. The oxidation state transition and crystal formation of vanadium oxide (VO_x) were affected by growth conditions and annealing temperatures. In this study, VO_x nanopowders were prepared by hydrothermal method, and annealing-induced characterizations of VO_x were analyzed. The morphologies, structures, composition, and optical properties of VO_x were characterized by SEM, XRD, EDX, FTIR, and UV–Vis spectroscopy. The results demonstrated that the annealing temperature significantly affected the transition of oxide states from the VOOH and VO_x clusters to V₂O₅ nanoparticles and the crystal size from amorphous to 38.96 nm which led to an increase in the optical band gap from 2.28, 2.26 to 2.39 and 2.38 eV as increasing calcination temperature and enhanced photocatalytic activity under sunlight irradiation. The energy dispersive X-ray (EDX) spectra reveal that the percentage molar mass between vanadium and oxygen changes due to the oxidation state transition and the formation of oxygen vacancies in V₂O₅. The relation between nanoparticle size, oxidation state, and crystal size was clarified by comparing EDX and XRD spectra.

Kirigami, as an ancient Japanese paper-cutting and origami art, has been widely used in the study of tensile properties of 2D nanomaterials. Diamane—a 2D nanodiamond film—has excellent electrical, thermal, and mechanical properties, while its ductility is poor, so this paper focuses on the enhancement of the tensile properties of Diamane by Kirigami. In this study, the tensile mechanical properties and deformation mechanisms of Diamane Kirigami were simulated and analyzed using molecular dynamics by varying three geometrical parameters, namely, the degree of overlap, the cutting rate, and the aspect ratio of the Kirigami cuts. The results show that the fracture strain (200–250%) of Diamane Kirigami can be 7–8 times higher than that of pristine Diamane (zigzag: 26.1%, armchair: 17.6%). For Diamane Kirigami in the armchair chiral configuration, more stable mechanical properties and ductility can be obtained in all parameters of the design. The I-shaped cutout shape and the stretching in the armchair direction can help Diamane Kirigami to significantly reduce the stress concentration at the ends of the cut and to increase the fracture strain. In conclusion, it is found in this paper that Diamane Kirigami possesses higher fracture strain compared to pristine Diamane, which will potentially expand their applications in engineering nanodevices and nanoelectronics.