Multibranched flower-like ZnO anchored on pectin/cellulose nanofiber aerogel skeleton for enhanced comprehensive antibacterial capabilities.

In this study, F-ZnO NPs were used as antibacterial agents, mussel bionic dopamine exerted its adhesive action to immobilize F-ZnO NPs on the pectin/CNF aerogel skeleton. Fruit and vegetable antimicrobial mats with safety, long duration of action and high efficiency were prepared and its potential application has been investigated. The results showed that a dopamine layer was deposited on the surface of the CNF, which promoted the tight adhesion of the F-ZnO NPs to the aerogel skeleton. The F-ZnO@D-CNF aerogel exhibited a slow release of zinc ions, with the first two days being 0.40 ± 0.16 and 1.01 ± 0.13 mg/mL. The aerogel was light, can stand on the petals without collapsing, has regular and uniform pore structure, good tensile/compressive properties and high antibacterial/anti-fungal properties. Strawberries packaged with F-ZnO@D-CNF aerogel exhibited an extended shelf life of 5 days. Additionally, the strawberries maintained a soluble solid content of 6.9 ± 0.82 % and a Vc content of 44.67 ± 3.51 mg/100 g. The weight loss, color and firmness were also notably superior to the other four groups. The final concentration of zinc ions in strawberries was 3.71 ± 0.28 µg/g, which is far below the recommended dietary intake.

Au/CdS Core-Shell Sensitized Actinomorphic Flower-Like ZnO Nanorods for Enhanced Photocatalytic Water Splitting Performance.

Herein, a novel actinomorphic flower-like ZnO/Au/CdS nanorods ternary composite photocatalyst is prepared to extend the light-responsive range, reduce the photogenerated charge carriers recombination, and ultimately improve the water splitting performance. Flower-like ZnO nanorods are synthesized by a chemical bath method and the CdS nanoparticles are sensitized by successive ionic layer adsorption and reaction method. Then the Au nanoparticles as co-catalysts are introduced by the photodeposition method to modify the interface of ZnO/CdS for reducing the photogenerated electron recombination rate and further improving the performance of water splitting. Detailed characterizations and measurements are employed to analyse the crystallinity, morphology, composition, and optical properties of the flower-like ZnO/Au/CdS nanorods samples. As a result, the flower-like ZnO/Au/CdS nanorod samples present significantly enhanced water splitting performance with a high gas evolution rate of 502.2 µmol/g/h, which is about 22.5 and 1.5 times higher than that of the pure ZnO sample and ZnO/CdS sample. The results demonstrate that the flower-like ZnO/Au/CdS nanorods ternary composite materials have great application potential in photocatalytic water splitting for the hydrogen evolution field.

Eco-friendly UV protective bionanocomposite based on Salep-mucilage/flower-like ZnO nanostructures to control photo-oxidation of kilka fish oil.

The carbohydrate source has shown great potential for preparing edible film structures, particularly as bionanocomposite edible films. In the present study, highly effective eco-friendly UV protective bionanocomposite based on Salep-mucilage (SaM)/ZnO flower-like (ZnOF) nanostructures were developed and characterized. To investigate microstructure and structure properties of SaM/ZnOF bionanocomposite, scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques, Fourier transformed infrared (FT-IR) and X-ray diffraction (XRD) were utilized. Our results showed that the increasing ZnOF content decreased transparency (~80%) of the bionanocomposites. The hunter color values observations confirmed the films' UV-Vis spectrum and their UV-protective properties. Additionally, SaM/ZnOF bionanocomposite were examined for their efficacy to decrease photo-oxidation in kilka fish oil under fluorescent light during 12 days of storage. The outcomes of our investigation confirm that SaM/ZnOF bionanocomposite with performance as the adequate light barrier to delay photo-oxidation of kilka fish oil during extended storage.

Cellulose controlled zinc oxide nanoparticles with adjustable morphology and their photocatalytic performances.

The cellulose fibers with different size and aspect ratio was used as the matrix for the controllable preparation of zinc oxide (ZnO) to synthesize ZnO/cellulose composite catalyst with adjustable photocatalytic properties. The ZnO with different morphology of sphere, sheet, and flower, was in-situ synthesized on cellulose fibers by chemical deposition method, the flower-like ZnO supported on cellulose fiber exhibited the best photocatalytic activity. Furthermore, with the decrease of fiber size, the morphology of ZnO changed from most sheet to fully self-assembled flower shape, and the average thickness of nanosheets was increased. Cellulose fibers with smaller size and higher aspect ratio were more likely to form a 3D network structure with rich pores and stable mechanical properties. Significantly, with the decreasing of fiber size, ZnO/NFC has excellent photocatalytic efficiency (100 %). All ZnO/cellulose composites can be recycled more than five times.

Flower-Like CuO/ZnO Hybrid Hierarchical Nanostructures Grown on Copper Substrate: Glycothermal Synthesis, Characterization, Hydrophobic and Anticorrosion Properties.

In this work we have demonstrated a facile formation of CuO nanostructures on copper substrates by the oxidation of copper foil in ethylene glycol (EG) at 80 °C. On immersing a prepared CuO film into a solution containing 0.1 g Zn(acac)2 in 20 mL EG for 8 h, ZnO flower-like microstructures composed of hierarchical three-dimensional (3D) aggregated nanoparticles and spherical architectures were spontaneously formed at 100 °C. The as-synthesized thin films and 3D microstructures were characterized using XRD, SEM, and EDS techniques. The effects of sodium dodecyl sulphate (SDS), cetyltrimethylammonium bromide (CTAB), and polyethylene glycol (PEG) 6000 as surfactants and stabilizers on the morphology of the CuO and ZnO structures were discussed. Possible growth mechanisms for the controlled organization of primary building units into CuO nanostructures and 3D flower-like ZnO architectures were proposed. The hydrophobic property of the products was characterized by means of water contact angle measurement. After simple surface modification with stearic acid and PDMS, the resulting films showed hydrophobic and even superhydrophobic characteristics due to their special surface energy and nano-microstructure morphology. Importantly, stable superhydrophobicity with a contact angle of 153.5° was successfully observed for CuO-ZnO microflowers after modification with PDMS. The electrochemical impedance measurements proved that the anticorrosion efficiency for the CuO/ZnO/PDMS sample was about 99%.

Aqueous norfloxacin sonocatalytic degradation with multilayer flower-like ZnO in the presence of peroxydisulfate.

Multilayer ZnO nanoflowers were synthesized through a simple precipitation method and characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS) and nitrogen absorption-desorption techniques. The FE-SEM images show the integrated morphology of an individual flower-like ZnO nanostructure, which is made of nano-platelets with uniform thickness (20-30nm). The average pore size and Brunauer-Emmet-Teller (BET) surface area of the as-synthesized ZnO were 27.25nm and 13.53m2/g. The sonocatalytic ability of the prepared samples was evaluated through norfloxacin (NF) degradation in an aqueous system using ultrasound (US) irradiation. To improve degradation efficiency, peroxydisulfate (Na2S2O8) was introduced to develop a US/ZnO/peroxydisulfate system, which exhibited an excellent synergistic effect. The effects of ZnO dosage, Na2S2O8 concentration, pH, and initial NF concentration were studied to determine the performances of the US/ZnO/peroxydisulfate process. Corresponding results showed that NF degradation rate increased with the increase of ZnO dosage but decreased with the increase of initial NF concentration. Under the optimal Na2S2O8 concentration of 0.1gL-1 at pH 9, the best degradation efficiency can be achieved. Moreover, based on the scavenging experiment results and literatures, NF degradation through US/ZnO/peroxydisulfate system is majorly induced by OH and SO4- radicals.