Nano

Antibiotics are a class of organic pollutant in the medical field for hundreds of years. Due to the continuous discharge of antibiotics in the environment, the phenomenon of pseudo-persistence of antibiotics is produced. Therefore, it is necessary to develop an advanced sustainable technology to remove antibiotics from water resources. In this study, Zeolite Imidazole Framework-8 (ZIF-8) was prepared by a simple and rapid method. Oxytetracycline (OTC) degradation was performed using ZIF-8 as a photocatalyst under visible light (VL) (500W xenon lamp) irradiation. Under different experimental conditions, ZIF-8 has strong catalytic removal performance for OTC. When the reaction conditions are: OTC concentration of 80 mg L${}^{-1}$, ZIF-8 concentration of 1.0gL${}^{-1}$, pH 5.96, the OTC removal rate is more than 90%. Through the detection and analysis of degradation intermediates, the possible degradation pathway of OTC was proposed. This study showed that the OTC removal rate of ZIF-8 could still reach 69% after four times of recycling. The results showed that the ZIF-8/VL system had high OTC removal efficiency and good recyclability.

This study presented the redox and magnetically responsive water-in-oil (W/O) Pickering emulsions stabilized by amphiphilic Fe₃O₄ nanoparticles. The magnetic nanoparticles synthesized by a conventional solvothermal method were further modified and characterized by Fourier-transform infrared (FT-IR), scanning electron microscopy (SEM) and energy-dispersive system (EDS). The results showed that Fe₃O₄ nanoparticles modified by 3-pyridyl-5-ferrocenyl-2-pyrazoline (PFP) showed strong interfacial activity, which could be used to emulsify toluene and water to prepare stable water-in-toluene emulsions. Moreover, due to the good redox properties of PFP, the emulsions could be switched between stable/unstable by adding trace amounts of oxidant and reducing agents alternately. At the same time, the emulsion droplets could be moved by applying magnetic field due to the superparamagnetic nature of Fe₃O₄ nanoparticles. Moreover, based on the electrostatic interaction, $\pi$–$\pi$ stacking and solubilization effect, the obtained Pickering emulsions could be used as an excellent extraction system for dye molecules Congo red with extraction efficiency up to 97%. In addition, the droplets of the emulsion could be reused by simple washing, which provided a new method for dye contaminant removal.

Sn₃O₄/g-C₃N₄ heterostructure nanomaterials were prepared by calcining melamine and the hydrothermal method. The microstructure and morphology of the synthesized specimen were characterized by X-ray diffraction (XRD), electron microscope (SEM and TEM) and nitrogen adsorption and desorption (BET). The photocatalytic activity was evaluated by the photodegradation of methylene blue (MB) under visible light irradiation and the electrochemical performance was tested under a typical three-electrode configuration. The results show that the Sn₃O₄/g-C₃N₄ heterojunctions exhibit more superior photocatalytic performance for degrading MB compared with single Sn₃O₄ and g-C₃N₄. The degradation rate of MB reaches up to a maximal 90.30% within 75min, which is far higher than that of Sn₃O₄ (61.30%). It is attributed to the effective interfacial contact between Sn₃O₄ and g-C₃N₄, which increases charge transfer and prolongs electron-hole separation time. The specific capacitance of Sn₃O₄/g-C₃N₄ is 28.6% higher than that of Sn₃O₄ due to the formation of a heterostructure.

Flower-like zinc tungstate/bismuth bromate (ZnWO₄/BiOBr) nanospheres were synthesized by a one-step hydrothermal method. The photocatalytic activity of the ZnWO₄/BiOBr heterojunction was evaluated by the photocatalytic degradation of 30mg/L of rhodamine B (RhB). It was found that 10% of ZnWO₄/BiOBr had the best degradation ability toward RhB. The degradation rate of RhB reached 97.7% (5 times and 358 times those of BiOBr and ZnWO₄, respectively) after light-emitting diode (LED) visible light irradiation for 30min. The ZnWO₄/BiOBr heterojunction had excellent photocatalytic activity because of its higher specific surface area and enhanced spectral response range. Moreover, the ZnWO₄/BiOBr heterojunction improved the charge separation efficiency and promoted the generation of more holes, $\cdot$ O${}_2^{-}$ and $\cdot$ OH radicals under light irradiation; thus, improving the degradation efficiency. Finally, a possible photocatalytic degradation mechanism was proposed. This study provides a good reference for the preparation of bismuth-based composite photocatalysts for the degradation and purification of organic pollutants.

The waterproof and breathable multifunctional films have been widely used in advanced wear protection, medical treatment, monitoring, and the aerospace industry. In this research, we prepared a new class/kind of waterproof and breathable intelligent (WBI) films through plasma surface treatment, which can be applied in the health care field. After air plasma treatments, the structural properties of polyethylene (PE) film were observed by Scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), Thermogravimetry (TG), and Differential scanning calorimetry (DSC). It was found that plasma treatment etches PE fibers due to the sputter etching effect of plasma modification, leading to a crystallinity decrease. In addition, the changes in water contact angle, air permeability, and water vapor transmission rate of PE films were measured to illustrate their waterproof and breathable properties. After plasma treatment, the water contact angle of PE film reduced from 112.67^∘ to 45^∘, indicating the PE surface converted from hydrophobic into hydrophilic. The air permeability increased to 0.450mm/s and the water vapor transmission rate increased to 1419.788g/m${}^2\cdot \mathrm{\text{h}}$, which means the treated PE films are breathable but not permeable to liquid water. The improved performance in waterproof and breathability expands the application of PE film in the pharmaceutical field.

In this article, we bring up facile one-step phytosynthesis of silver (Ag), gold (Au) and Ag/Au bimetallic nanoparticles by reduction of silver nitrate (AgNO₃) and tetrachloroauric acid (HAuCl₄) solution, using aqueous leaf extract of Moringa oleifera, known for its medicinal properties. These nanoparticles were evaluated for their cytotoxicity potential against human hepatocellular carcinoma cells (HepG2), triple-negative breast cancer cell lines (MDA-MB-231) and breast cancer cell lines (MCF-7). Physical characterization of these metal nanoparticles was done using different nanoparticles analysis techniques, which include UV–Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopic analysis, dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDAX). Our data suggest that these phytosynthesized nanoparticles showed a dose-dependent cytotoxic effect on all the three tested cancer cell lines. However, AuNPs are reported to have higher cytotoxic potential with IC${}_{50}$ value in the range of 9.20–21.46$\mu$g/mL compared to that of bimetallic NPs (Ag–Au NPs) with IC${}_{50}$ value of 37.22–49.94$\mu$g/mL. Whereas, silver NPs (AgNPs) didn’t show cytotoxic activity till a concentration of 60$\mu$g/mL in all the three cell lines tested for 24h. Hence, this study supports the effectiveness of phytosynthesized AuNPs for the development of anticancer agents.

$M$-type hexagonal ferrites with compositions Ca${}_{1-x}$Cr_xFe${}_{12}$O${}_{19}$ at ($x=0.1$, 0.2, 0.3, 0.4, 0.5) were successfully prepared by sol–gel auto combustion method and then immersed with polyvinyl alcohol (PVA) by ultrasound-assisted in situ emulsion technique. The results indicate that the synthesized nanoparticles were diffused homogeneously in PVA retaining the size and shape of the particle. The single-phase $M$-type hexagonal structure was revealed by X-ray diffraction (XRD) with extra 101 peak of PVA at 2$\theta =18^{\circ }$. The suitable signal-to-noise ratio in the high density recording media can be achieved due to the small particle size of the prepared composites as compared to pure hexaferrites. The interaction between PVA and nanoparticles was confirmed by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) images revealed the homogeneous distribution of grains, the crystallite size was measured from SEM (25–38nm), and it is also in agreement as calculated from the Scherer formula. Dielectric properties were also explored in the range of 1 MHz–3 GHz frequencies. Dielectric constant and dielectric loss were found to decrease with increasing frequency and decrease with the addition of ferrite ratio in the polymer matrix. This impact is because of the grain boundary at low frequency regime. The occurrence of resonance at high frequency regime recommends the investigated samples for multilayer chip inductor.