Dispersion Of ZnO Nanoparticles Research Articles

Enhancing physical characteristics and antibacterial efficacy of chitosan through investigation of microwave-assisted chemically formulated chitosan-coated ZnO and chitosan/ZnO physical composite

This study investigates the creation and analysis of chitosan-zinc oxide (CS-ZnO) nanocomposites, exploring their effectiveness in inhibiting bacteria. Two synthesis approaches, physical and chemical, were utilized. The CS-ZnO nanocomposites demonstrated strong antibacterial properties, especially against Staphylococcus aureus, a Gram-positive bacterium. Chemically synthesized nanocomposites (CZ10 and CZ100) exhibited larger inhibition zones (16.4 mm and 18.7 mm) compared to physically prepared CS-Z5 and CS-Z20 (12.2 mm and 13.8 mm) against Staphylococcus aureus. Moreover, CZ nanocomposites displayed enhanced thermal stability, with decomposition temperatures of 281°C and 290°C, surpassing CS-Z5 and CS-Z20 (260°C and 258°C). The residual mass percentages at 800°C were significantly higher for CZ10 and CZ100 (58% and 61%) than for CS-Z5 and CS-Z20 (36% and 34%). UV–Visible spectroscopy revealed reduced band gaps in the CS-ZnO nanocomposites, indicating improved light absorption. Transmission electron microscopy (TEM) confirmed uniform dispersion of ZnO nanoparticles within the chitosan matrix. In conclusion, this research underscores the impressive antimicrobial potential of CS-ZnO nanocomposites, especially against Gram-positive bacteria, and highlights their enhanced thermal stability. These findings hold promise for diverse applications in industries such as medicine, pharmaceuticals, and materials science, contributing to the development of sustainable materials with robust antimicrobial properties.

Efficient Catalytic Degradation of Methyl Orange by Various ZnO-Doped Lignin-Based Carbons.

Herein, a series of ZnO-doped lignin-based carbons (LC/ZnO) were successfully prepared from different types of lignin and used for methyl orange (MO) photocatalytic degradation. The apparent morphology, internal structure, and photoelectric properties of prepared LC/ZnO composites and their effects on subsequent MO photocatalytic degradation were investigated by various characterization techniques. The results showed that the LC/ZnO composites that were prepared in this work mainly consisted of highly dispersed ZnO nanoparticles and lignin-based carbon nano-sheets, which were beneficial for subsequent photogenerated electrons and holes formation, dispersion, and migration. The MO could be significantly degraded with various ZnO-doped lignin-based carbons, especially over the LCSL/ZnO, and the maximum degradation rate was 96.9% within 30 min under the simulated 300w sunlight exposure. The experiments of free radical elimination showed that the photocatalytic degradation of MO over LC/ZnO were a result of the co-action of multiple free radicals, and h+ might play the predominant roles in MO degradation. In addition, the pH of the solution had little effect on MO degradation, and the MO could be effectively degraded even in an alkaline solution of pH = 12.0. The cycling experiments showed that the prepared LC/ZnO had a good stability for MO photodegradation, especially for LCSL/ZnO, even after 5 times recycling, and the degradation rate of MO only dropped from 97.0% to 93.0%. The research not only provided a fundamental theory for the efficient photocatalytic degradation of MO by LC/ZnO composites, but also offered a new insight into lignin valorization.

Facile synthesis of ZnO/halloysite nanotube composite with greatly enhanced photocatalytic performance

ZnO/halloysite nanotube composites (ZH-X, X = 10, 30, 40, 50, 70), with different mass ratio of ZnO to halloysite nanotubes (HNTs), were fabricated successfully via a facile wet chemical technique in anhydrous ethanol under a mild reaction condition. ZnO nanoparticles about 9 nm in size were inhibited from agglomeration and loaded homogeneously on the surface of HNTs. The microstructure, specific surface area, light absorption ability, photocatalytic performance, etc. of the ZH-X composites varied with the mass ratio of ZnO to HNTs. All ZH-X composites displayed better photocatalytic performance than pure ZnO sample did. With the increasing of ZnO content, the photocatalytic activity of ZH-X composite toward degrading methylene blue (MB) solution strengthened gradually and reached the maximum by ZH-40 composite (with ZnO content of 28.57 wt%), then decreased step by step. ZH-40 (0.05 g) removed 99.88% of MB (100 mL, 15 mg/L) after adsorption in dark and then photocatalytic degradation for 60 min, and whose photocatalytic reaction rate constant was 5.73 times that of pure ZnO. The enhanced photocatalytic efficiency of ZH-40 composite was attributed to the interfacial effect of ZnO and HNTs as well as the dispersed ZnO nanoparticles, which maintained the adsorption ability of HNTs and improved the separation and migration of photo-generated electron and hole pairs. This work provides a feasible method for loading photocatalyst on clay mineral to realize efficient photocatalysis.

An efficient method to improve the dispersion and biocompatibility of ZnO nanoparticles

As an important inorganic antibacterial nanomaterial, zinc oxide nanoparticles (ZnO NPs) have been widely used in biomedical fields. However, the poor dispersion and potential toxicity greatly limit its application. Surface modification is an effective method to improve the dispersion and biocompatibility of ZnO NPs. In this work, ε-polylysine (ε-PL) was grafted on the surface of ZnO NPs via the combination of mussel inspired method and “Michael addition” reaction. The results showed that the ε-PL grafted ZnO (ZnO@ε-PL) could disperse stably in water more than 72 h, demonstrating ε-PL greatly improves the dispersion of ZnO NPs. Furthermore, the cells viability of ZnO@ε-PL at high concentrations (500 μg/mL) was 143.05 ± 12.63%, indicating that the biocompatibility of ZnO@ε-PL is much better than that of ZnO NPs. This study proposed a feasible and effective strategy to improve the dispersion and biocompatibility of ZnO NPs, which may expand the application of ZnO NPs in the biological field.

In‐situ generated ZnO nanoparticles for enhanced performance of thin film nanocomposite membrane in forward osmosis process

AbstractThis work developed a novel approach to the in‐situ synthesis of ZnO nanoparticles to modify the polysulfone (PSf) porous membrane substrate. The zinc acetate was added to the casting solution, and ZnO nanoparticles were synthesized during phase inversion. The non‐solvent pH and zinc acetate concentration controlled the ZnO synthesis and loading. Their effect on the substrates properties in terms of morphology, hydrophilicity and porosity was studied thoroughly. The result shows that the ZnO nanoparticles was not formed in acidic pH, while ZnO nanoparticles with size of 20 nm could be easily formed in basic pH. The successful synthesis of ZnO nanoparticles was investigated using FTIR and EDX analysis. The EDX images verify that in‐situ synthesis led to a more uniform dispersion than conventional incorporation method. Then the effect of ZnO loading on the interfacial reaction and polyamide (PA) structure was investigated. SEM images verify the successful synthesis of a uniform and defect‐free PA thin film on ZnO modified substrates. FO performance results show an enhancement in water flux and salt rejection as a result of ZnO incorporation in thin film nanocomposite (TFN) membranes, where TFN 1 wt.% in‐situ membrane showed 40% higher water flux than the control TFC membrane. The porous and hydrophile substrate in TFN 1 wt.% in‐situ membrane is responsible for improved separation performance. These modified membranes displayed uniform dispersion of ZnO nanoparticles within substrates, confirming that this method could effectively restrain the aggregation of the nanoparticles.

Dielectric Relaxation Behavior and Electrical Conduction Mechanism of PVA/ZnO Nanocomposites for Flexible Electronic Device Application

Transport properties of polyvinyl alcohol/ZnO nanocomposites (PVA/ZnO) of varying ZnO nanofiller are studied focussing on their potential application in electronic device application. The structural, morphological, and elemental composition studies of the prepared samples are done by X‐ray diffraction (XRD), scanning electron microscope (SEM), and energy‐dispersive X‐ray analysis (EDX). XRD confirms the formation of nanocomposites. SEM image shows the dispersion of ZnO nanoparticles on the surface of PVA matrix. EDX verifies that no external impurities are present in the nanocomposite samples. Frequency‐ and temperature‐dependent dielectric measurement of the samples reveals maximum dielectric constant at PVA/15 wt% ZnO nanocomposite. Dielectric loss results show a lossless behavior at higher frequencies (<0.2), indicating their suitability for high‐frequency applications. The AC conductivity studies reveal that electrical conduction mechanism in the nanocomposites is governed by the correlated barrier hopping mechanism. Activation energy of the samples reveals the presence of two thermally activated transport mechanism above and below 353 K. The imaginary part of electric modulus with frequency shows a single relaxation peak indicating the transition from long‐range to short‐range mobility with increasing frequency and temperature above 353 K. The contribution of grain and grain boundary in the electrical conduction process is confirmed from the Nyquist plot.

Ultrafast Carbonized Wood of Electrode-Scaled Aligned-Porous Structure for High-Performance Lithium Batteries

The use of carbonized wood in various functional devices is attracting considerable attention due to its low cost, vertical channels, and high electrical conduction. However, the conventional carbonization method requires a long processing time and an inert atmosphere. Here, a microwave-assisted ultrafast carbonization technique was developed that carbonizes natural wood in seconds without the need for an inert atmosphere, and the obtained aligned-porous carbonized wood provided an excellent electrochemical performance as an anode material for lithium-ion batteries. This ultrafast carbonization technique simultaneously produced ZnO nanoparticles during the carbonization process that were uniformly distributed on the aligned-porous carbon. The hierarchical structure of carbonized wood functionalized with ZnO nanoparticles was used as a host for achieving high-performance lithium–sulfur batteries: the highly conductive carbonized wood framework with vertical channels provided good electron transport pathways, and the homogeneously dispersed ZnO nanoparticles effectively adsorbed lithium polysulfide and catalyzed its conversion reactions. In summary, a new method was developed to realize the ultrafast carbonization of biomass materials with decorated metal oxide nanoparticles.

Learning in colloids: Synapse-like ZnO + DMSO colloid

Colloids subjected to electrical stimuli exhibit a reconfiguration that might be used to store information and potentially compute. In a colloidal suspension of ZnO nanoparticles in DMSO, we investigated the learning, memorization, time and stimulation’s voltage dependence of conductive network formation. The relationships between the critical resistance and stimulation time have been reconstructed. The critical voltage (i.e., the stimulation voltage required to drop the resistance) was found to decrease as stimulation time increased. We characterized a dispersion of conductive ZnO nanoparticles in the DMSO polymeric matrix using FESEM and UV–visible absorption spectrum.

Alternative Polyurethane/Gutta-Percha/ZnO Biocomposite for Root Canal Therapy Based on an Efficient Melt Extrusion Additive Manufacturing Strategy

This work aims to investigate dental root filling custom gutta-percha (GP) properties based on melt extrusion 3D printing for periapical periodontal disease treatment. Zinc oxide nanoparticles are incorporated into polyurethane/gutta-percha (PGB) composites. A polyurethane/gutta-percha/ZnO (PGB-Zn) biocomposite including BaSO4, polyurethane (PU), GP, and ZnO nanoparticles is designed and fabricated. To improve the dispersion of ZnO nanoparticles, rosin is chosen to modify the surface of the ZnO nanoparticles. The PGB-Zn biocomposite exhibits a maximum tensile strength of 26.795 ± 1.173 MPa and a flexural strength of 6.037 ± 0.37 MPa. The chemical interaction between the nanoparticles and the matrix is found in the physical and mechanical characterization of the polyurethane/gutta-percha/ZnO (PGB-Zn) biocomposite. The inhibition zone test and absorbance photometry show that the composite material inhibits and kills Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The CCK-8 experimental results show that the PGB-Zn biocomposite has a cytotoxicity level of 0-I. The obtained PGB-Zn biocomposite in this work can be used for accurate root canal therapy as a filling biocomposite by a fused extrusion method, which effectively decreases the potential risk of the clinical implementation of periapical periodontal disease treatment.

Linear/Nonlinear Optical Characteristics of ZnO-Doped PVA/PVP Polymeric Films for Electronic and Optical Limiting Applications

ZnO-doped Polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) polymeric films were prepared in this study through an easy and inexpensive solution-casting method. The scope of the study was based on the structural, dielectric, and optical parameters, as well as on the optical limiting effects of the ZnO-doped polymer blend (PB) as nanocomposite films. The X-ray diffraction (XRD) analysis indicated that the synthesized nanocomposites were semicrystalline. The calculated crystalline size of the polymeric semicrystalline peak decreased as ZnO increased or enhanced the blend polymer. Fourier’s transformer infrared (FT-IR) study confirmed a substantial dispersion of ZnO nanoparticles in a polymeric PVA/PVP matrix. The optical absorption properties suggested focusing on the surface plasmonic peak (SPR). The refractive index values ranged from 1.718 for the pure PB ZnO0 sample in the Hossam, Ibrahim, and Heba model to 3.036 for the PB ZnO5 film from the Anani model. Nonlinear optical parameters (χ((3)), and n(2)) were calculated and analyzed for the PB ZnO nanocomposite films under investigation. The maximum value for χ((1)) was 0.550, while for χ((3)), its susceptibility value was 155.85 × 10−13 esu, and for the nonlinear refractive index (n((2)), it was 20.87 × 10−11 esu. A gradual decrease was revealed in the optical limiting sources, as a high content of ZnO was induced in the blend PVA/PVP polymer. Due to their unique properties, these materials can be used in electronic and optoelectronic devices.

Critical Crystallographic Transition in Violation of Kasha’s Rule of Size-Specific ZnO Quantum Dots

Investigation of the intrinsic relationship between crystallography and electronic properties may provide an avenue to unravel the photophysical aspects of semiconductor nanostructures. Since the 1980s, semiconducting materials at the nanoscale dimensions have been of immense scientific interest because of the unique quantum characteristics beyond a particular size limit. Prudent advances in the synthetic strategies of naked ZnO quantum dots have offered the opportunity to imbue the structure–property relationship of nanostructured systems. Seven size-specific ZnO nanospheres have been synthesized through alkaline hydrolysis of the precursor salt in the presence of alcohol in the reaction medium. The photoluminescence behavior of colloidal dispersion of ZnO nanoparticles has been studied as a function of excitation wavelength with a periodic interval of 10 nm in the range of 290–430 nm. It has been observed that changes in the excitation wavelength shift the emission spectrum in a regular manner independent of the size of ZnO particles under investigation. The empirical proposition in the framework of Kasha’s rule has been established as a milestone of spectroscopy, being validated in tens of thousands of fluorophore systems; meanwhile, although obscure, anomalous cases have also been observed both in molecular and nanoscale systems. Crystallographic analysis has shown that there occurs a structural transition that determines the localization of electronic energy levels in the experimental size range of the ZnO particles. Therefore, the salient feature of physical significance is that crystallographic transition appears to exhibit the excitation wavelength-dependent shift of the photoluminescence maximum and is therefore the violation of Kasha’s rule for the ZnO quantum dots.

Rapid and facile synthesis of Z-scheme ZnO/g-C3N4 heterostructure as efficient visible light-driven photocatalysts for dye degradation and hydrogen evolution reaction

The coupling of two-different semiconductors which are photocatalytically active is gaining popularity in recent years because the heterojunction can decrease the rate of recombination of photoexcited electron-hole pairs and enhance the photocatalytic activity. In the current work, ZnO/g-C3N4 heterojunction hybrids have been generated by simple solution mixing of the dispersed ZnO and graphitic carbon nitride (g-C3N4) nanoparticles. The ZnO/g-C3N4 composite under visible light exhibits 91.5% degradation of the methylene blue (MB) dye in 120 min and also demonstrated excellent cyclic stability. Mechanistic studies and dye degradation experiments carried out in the presence of scavengers (ascorbic acid, potassium dichromate and ammonium oxalate) revealed that the generated superoxide radical (O2•‒) and hydroxyl radicals play a crucial role in MB dye degradation using ZnO/g-C3N4 as a photocatalyst. Further, the ZnO/g-C3N4 composite exhibits improved hydrogen evolution reaction (HER) activity (1358 μmol g-1 h-1) compared to the pristine ZnO nanoparticles (545 μmol g-1 h-1) and g-C3N4 (238 μmol g-1 h-1). The superior HER activity of the hybrid is ascribed to the increased charge-transfer rate owing to the better interfacial contact between the heterocomponents. Secondly, the nanoparticle nature of ZnO and g-C3N4 heterocomponents provides more exposed edge sites and thereby gives significant photocatalytic activity.

Developing efficient CuO nanoplate/ZnO nanoparticle hybrid photocatalysts for methylene blue degradation under visible light.

CuO/ZnO nanocomposites with different components can overcome the drawbacks of previously used photocatalysts owing to their promotion in charge separation and transportation, light absorption, and the photo-oxidation of dyes. In this study, CuO nanoplates were synthesized by the hydrothermal method, while ZnO nanoparticles were fabricated by the precipitation method. A series of CuO/ZnO nanocomposites with different ZnO-to-CuO weight ratios, namely, 2 : 8, 4 : 6, 5 : 5, 6 : 4, and 8 : 2 were obtained via a mixing process. X-ray diffraction patterns confirmed the presence of hexagonal wurtzite ZnO and monoclinic CuO in the synthesized CuO/ZnO nanocomposites. Scanning electron microscopy showed the dispersion of ZnO nanoparticles on the surface of CuO nanoplates. Ultraviolet-visible absorption spectra exhibited a slight red-shift in the absorption edge of binary oxides relative to pure ZnO or CuO. All samples were employed for the photocatalytic degradation of methylene blue (MB) under visible light irradiation. The composite samples exhibited enhanced photocatalytic performance compared with pristine CuO or ZnO. This study aimed to examine the effect of the ZnO-to-CuO weight ratio on their photocatalytic performance. The results indicated that among all the synthesized nanocomposites and pristine oxides, the nanocomposite with ZnO and CuO in a proportion of 4 : 6 shows the highest photodegradation activity for the removal of MB with 93% MB photodegraded within 60 min at an initial MB concentration of 5 ppm. The photocatalytic kinetic data were described well by the pseudo-first-order model with a high correlation coefficient of 0.95. The photocatalytic mechanism of the mixed metal oxide was proposed and discussed in detail. The photodegradation characteristic of CuO/ZnO nanostructures is valuable for methylene blue degradation from aqueous solutions as well as environmental purification in various fields.

Facile synthesis of Flower-like ZnO loading Cellulose-Chitosan nanocomposite films by biomimetic approach with enhanced performance

Flower-like ZnO composed of nanoplate was synthesized using biopolymers cellulose and chitosan via biomimetic strategy under a mild alkaline solution. In this work, we described ZnO-based cellulose/chitosan hybrid nanocomposites with enhanced mechanical, thermal, photocatalytic and antibacterial properties. Due to the uniform dispersion of ZnO nanoparticles with mean sizes of approximately 10 nm and the hydrogen bonds formed between ZnO and polysaccharides, CCZ exhibited enhanced tensile strength, which grew 1.5 times compared to neat CCF. CCZ exhibited superior antibacterial and photocatalytic activities. The width of inhibition zones around CCZ films reached 15.6–20.6 mm and 8.4–13.6 mm for S. aureus and E. coli, respectively. Furthermore, biopolymers cellulose and chitosan interacting with ZnO NPs tuned the bandgap of the semiconductor, leading to the enhancement of photocatalytic abilities. 87.1 % of methyl orange (MO) was degraded by CCZ nanocomposite within 50 min. CCZ nanocomposite remained stable after 3 cycles. The facile method extended biomimetic strategy to construct functional nanocomposite materials and provided a new route to synthesize specific morphology of ZnO NPs for various practical applications such as wastewater treatment, antibacterial materials, and solar cells.

Numerical analysis of solar energy storage within a double pipe utilizing nanoparticles for expedition of melting

The current work proposes the combination of thermal storage and solar concentrating systems. To improve the low conduction mode of pure paraffin, not only the new style of fins but also dispersing ZnO nano-powders were suggested. The numerical procedure has been verified with the reported outputs in previous literature and good accommodation has been demonstrated. The utilized technique for modeling transient charging phenomena is enthalpy-porosity in which homogeneous model for prediction of paraffin properties were proposed. To determine the efficacy of angle of star-spline fins, simulations for all three proposed configurations have been done and outputs have been summarized in contours and plots. In existence of sunlight, the reflector makes the sun rays to concentrate along absorber tube and temperature of testing fluid augments. Such hot fluid flows within the inner pipe of double pipe system which contains paraffin in annulus region. With change of θ from 30° to 45° and 60°, the melting period saved to 13.14% and 18.61%, respectively. Adding ZnO nanoparticles help to augment the conduction mode and melting period declines around 4.79%. The lowest needed time for melting is about 4.88 h which is associated to case with φ = 0.035 and θ = 60°. • The combination of thermal storage and solar concentrating unit was proposed. • Dispersing ZnO nanoparticles and installing star-spline fins were applied. • With change of θ from 30° to 60°, the melting period saved to 18.61%. • Adding ZnO nanoparticles help to reduce melting period around 4.79%. • The quickest process occurs when φ = 0.035 and θ = 60°.

Ionic strength induced local electrodeposition of ZnO nanoparticles

The controlled maskless deposition of nanomaterials locally on surfaces is challenging and of relevance to numerous fields and applications, such as sensing and catalysis. Forming patterns of pre-synthesized, and therefore, well-defined NPs should become a general and simple building approach for manipulating surfaces. Electrochemical deposition of NPs under mild potentials is not common and is based on destabilizing nanomaterial dispersions by an electrical field. This approach that is termed from “nano to nano” is used here for the local deposition of ZnO NPs. Specifically, we employ scanning electrochemical microscopy (SECM) as a means of increasing locally the ionic strength by generating a flux of AuCl4− in a ZnO nanoparticle dispersion. The gold ions bind instantaneously to the ZnO NPs and drive their local deposition on a biased indium tin oxide (ITO) surface to form ZnO nanoparticle patterns embedded in Au. The ratio between Au and ZnO can be changed by controlling the AuCl4− flux at the SECM tip and the ITO potential. The as-electrodeposited ZnO NPs are characterized by microscopy and spectroscopy. Furthermore, the micron-sized Au-ZnO patterns are used as recyclable surface-enhanced Raman scattering (SERS) active substrates for the sensitive detection of a dye. The latter is only an example of the potential of such local nanomaterial-based patterns that can be readily formed by our approach.

Intensification of photocatalytic wastewater treatment using a novel continuous microcapillary photoreactor irradiated by visible LED lights

This paper presents a novel multi microcapillary photoreactor capped with two transparent poly (methyl methacrylate) (PMMA) plates irradiated by a 60 W visible LED SMD lamp for intensified degradation of methyl orange (MO). Copper phthalocyanine doped Bi2O3-ZnO nanophotocatalysts (CuPc-Bi2O3-ZnO) were coated on inner walls of the microcapillaries. XRD and FESEM-EDX analyses confirmed highly dispersion of copper phthalocyanine, Bi2O3 and ZnO nanoparticles with approximate size of 41 nm on the inner walls of the microcapillary tubes. DRS analysis indicated CuPc doping resulted in red shift of the light absorption region and reduction of the bandgap energy to 2.68 eV. Photocatalytic space-time yield for the fabricated intensified microphotoreactor was obtained 3.74 × 10−2 m3 wastewater/m3 reactor.day.kW, while this benchmark was 4 orders of magnitude lower, 7.5 × 10−6 m3 wastewater/m3 reactor.day.kW, for a studied batch photoreactor, and 2.17 × 10−2 m3 wastewater/m3 reactor.day.kW, for a tubular flow photoreactor, revealing positive effect of process intensification on efficiency of the photocatalytic degradation of MO. MO degradation percent in the fabricated microphotoreactor, the studied batch photoreactor, and the tubular flow photoreactor was obtained 90.83%, 58.6%, and 65.33%, respectively, as well. Study on the effect of length (30, 45, 60 mm) and diameter (400, 850 μm) of the microcapillary tubes illustrated MO conversion decreased from 94.19% (30 mm length, 850 μm diameter) to 58.01 % (45 mm length, 400 μm diameter) because according to laser analysis and COMSOL simulations with narrowing and elongating tubes, photon loss, pressure drop, and turbulence in tubes increased.

MOF-derived magnetic-dielectric balanced Co@ZnO@N-doped carbon composite materials for strong microwave absorption

Composite materials with magnetic and dielectric properties are considered as promising candidates for electromagnetic wave absorbing materials. However, adjusting the electrical and magnetic properties of materials at the same time faces a huge challenge. Here, using metal organic frameworks (MOFs) as the precursors, highly dispersed Co and ZnO nanoparticles are uniformly confined in the graphitized nitrogen-doped carbon framework, building a balanced electromagnetic performance in the absorbent. Meanwhile, by adding template agents and changing the metal source, the shape of metal/carbon-based materials derived from mostly controllable MOFs has realized the transformation from six-pointed star, flower-like, cube-like to random stone-like. Thanks to its special morphology and balanced magnetic dielectric multiloss mechanism, the six-pointed star Co@ZnO@NC-a exhibits a minimum reflection loss (RLmin) of −61.9 dB at 8.7 GHz and the effective absorption bandwidth (EAB) is 5.5 GHz (11.6–17.1 GHz) at 2.3 mm thickness. These results provide a new design strategy for fabricating high performance magnetic dielectric absorbing materials with special morphology.

TiO2–ZnO/Au ternary heterojunction nanocomposite: Excellent antibacterial property and visible-light photocatalytic hydrogen production efficiency

TiO 2 –ZnO/Au ternary heterojunction nanocomposite was fabricated by producing TiO 2 nanosheets first using solvent-thermal method followed by Au deposition and ZnO deposition respectively. The TiO 2 nanosheets provide a relatively large surface area for the good dispersion of ZnO nanoparticles and Au particles and sufficient contact with the medium, which contribute to the excellent photocatalytic performances of TiO 2 –ZnO/Au heterojunction composite. The phases and structures, morphologies, surface and optical properties of the ternary heterojunction composite are well-characterized. Subsequently, the photocatalytic hydrogen generation of TiO 2 –ZnO/Au is evaluated under visible light irradiation. TiO 2 –ZnO/Au ternary heterojunction composite has efficient light absorption ability and excellent performances in photocatalytic hydrogen generation (1068 μmol/g under the irradiation of visible light for 4 h) and antibacterial properties (reaching 98.2%). TiO 2 –ZnO/Au ternary heterojunction nanocomposite has a large potential to be used in areas such as interior wall coating.

Preparation of highly dispersed ZnO nanoparticles to fabricate ultraviolet-shielding poly(vinyl chloride) films

Preparation of highly dispersed ZnO nanoparticles to fabricate ultraviolet-shielding poly(vinyl chloride) films