Different Content Of ZnO Research Articles

Fabrication of ZnO–GO hybrid for enhancement of chemically bonded phosphate ceramic coatings corrosion protection performance on AISI304L stainless steel

AbstractIn this paper, a solvothermal method is used to prepare nano‐sized zinc oxide‐graphene oxide (ZnO–GO) hybrid, and the ZnO–GO hybrid is characterized by X‐ray diffraction analysis, Raman, Fourier transform infrared spectroscopy, and scanning electron microscopy. In addition, chemically bonded phosphate ceramics coatings with different content of ZnO–GO hybrid are prepared on the stainless steel through the sol‐gel method. The corrosion performance of the coatings is evaluated by electrochemical properties and the analysis of the surface and cross morphology of the coating. Results indicate ZnO–GO hybrid significantly enhances the compactness and corrosive behavior of the coating because the overlapping structure of GO flake improves the barrier performance of the coating. Besides, ZnO nanoparticles on the surface of GO can react with aluminum dihydrogen phosphate binder, in that case the adhesion between GO and the coating is improved.

In vitro Bioactivity, Bio-Corrosion Resistance and Antibacterial Property of Laser Cladded HA Coatings with Different Content of ZnO on Ti-6Al-4V Substrate

HA/ZnO coatings with varying content of ZnO were fabricated on Ti-6Al-4V substrate to enhance its bioactivity and antibacterial ability. The main phases are identified as CaTiO3, Ca3(PO4)2, ZnTiO3 and CaO. The coatings with higher ZnO content presented smaller grain size, resulting in a higher surface free energy and better wettability. Consequently, the mineralization of the ZnO/HA coatings, especially for the higher ZnO content samples were improved, indicating better enhanced in vitro bioactivity. The ZnO-HA coated Ti-6Al-4V presented better corrosion resistance than bare Ti-6Al-4V substrate. Furthermore, better corrosion resistance was obtained by increasing ZnO content in the precursor. The antimicrobial ratio of all coatings was approximately 100%, indicating the ZnO doped HA coatings presented excellent antibacterial ability.

Probing local structure of ZnO-modified Pb(Mg1/3Nb2/3)0.9Ti0.1O3 ceramic with synchrotron X-ray absorption spectroscopy technique

ABSTRACTThis work aims to study the effects of ZnO modifications on local structures of Pb(Mg1/3Nb2/3)0.9Ti0.1O3 (PMNT) ceramics. Different contents of ZnO (0, 0.4, 2.0, 4.0 and 11.0 mol%) were added into PMNT ceramics. The local structures of the samples were characterized by synchrotron X-ray absorption spectroscopy (XAS). X-ray absorption near-edge structure (XANES) spectra of both Zn and Ti K-edges were displayed. The Zn K-edge energy values of all samples were in the range of 9660–9666 eV. The Zn ions incorporated in all ceramics were in the form of Zn2+. The value of Ti K-edge energy, which was equal to 4979 eV, did not change with ZnO modifications. Comparing the experimental Zn K-edge XANES spectra to the spectra simulated via FTFF program confirmed the substitution of the Zn ions for B-site ions. The intensity and the area under curve of the pre-edge peak of Ti K-edge gradually increased with increasing ZnO content up to 4.0 mol%. This suggested a gradual change in the displacement out from octahedral centers of Ti ions. This could be an evidence of the enhancement in ferroelectric order of ZnO-modified PMNT ceramics.

Influence of ZnO on the crystal phase and properties of lithium disilicate glass-ceramic doped with Ag2O

The purpose of this paper was to investigate the influence of ZnO on antibacterial properties, flexural strength and translucency of a novel dental lithium disilicate glass-ceramic doped with Ag2O by changing crystal phase composition and microstructure. Investigations were carried out by means of differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, antibacterial test, toxicity test, flexural strength and translucency test, respectively. Research showed that the introduction of ZnO increased the antibacterial activities of the lithium disilicate glass-ceramic doped with Ag2O. But with the increasing of the ZnO content, the translucency and flexural strength reduced, because the introduction of ZnO hampered the transition from Li2SiO3 to Li2Si2O5 and formed the crystal phase of Li3Zn0.5SiO4. The flexural strength values of glass ceramic were above 300MPa when the content of ZnO was below 4wt%. The lithium disilicate glass-ceramic doped with 0.2wt% Ag2O and different content of ZnO had a large range of translucency. This material can be better applied to dental restoration.

Preparation of One-dimensional ZnO/Bi2O3 Heterostructures Nanomaterial for Visible Light Photocatalysis

We use a simple route to prepare ZnO@Bi2O3 heterostructures at room temperature by the solid-state reaction method. The paper discussed morphology and photocatalytic properties of different content of ZnO@ Bi2O3 composite nanomaterials. The as-prepared different content of ZnO@ Bi2O3 composite with different content were characterized by SEM, TEM, XRD and Uv-vis spectrometry. We find that the Bi2O3 nanoparticles are well dispersed on the ZnO Nano rods. The result shows that we can the absorption of solar light can be enhanced by coating Bi2O3 and zinc oxide /bismuth oxide sample in sunlight irradiation shows the best photocatalytic activity under sunlight irradiation

Effect of replacement of B2O3 by ZnO on preparation and properties of transparent cordierite-based glass-ceramics

The effect of B2O3 replacement by different contents of ZnO on the preparation and various properties of transparent cordierite-based glass-ceramics was deeply investigated. With ZnO addition, the glass transition temperature (Tg) changed slightly, while the crystallization temperature (Tc) decreased greatly, which was confirmed by the DSC results. According to the X-ray diffraction and TEM analysis, ZnO affected the type of the crystal phases, as well as increased the crystallinity and changed the grain size. In addition, the transmittance, thermal expansion coefficient, Vickers hardness and bending strength of glass-ceramics were greatly influenced by the content of ZnO. Transparent glass-ceramics with excellent optical, thermal and physical properties were prepared by nucleating the sample with 2mol% ZnO content at 820°C for 6h and then crystallizing it at 1000°C for 6h.

Microwave assisted hydrothermal synthesis and characterization of ZnO–TNT composites

TiO2 nanotubes with different contents of ZnO (3–40 wt.% ZnO) have been successfully synthesized by microwave assisted hydrothermal process by using commercial TiO2-P25 as a precursor. The phase and crystallinity of the obtained ZnO–TNT were analyzed by X-ray Diffraction (XRD). The surface area of the ZnO–TNT was determined by BET method. The effect of the different contents of ZnO on morphology of TiO2 nanotubes was investigated by SEM and TEM. Optical properties and band gap energy of ZnO–TNT were calculated by using UV–vis DRS spectroscopy and modified Kubelka–Munk equation. Photocatalytic performance of ZnO–TNT was investigated by degradation of rhodamine B (RhB) dye under UV and visible light irradiation. Increasing ZnO content in TNT gradually decreased the diameter and length of nanotubes. Furthermore, addition of 40 wt.% ZnO into the TNT exceeded the saturation limit of ion exchangeability of Zn2+ and Na+ ions and aggregation of finely dispersed ZnO particles on the surface of TNT were observed. The ZnO–TNT has shown relatively larger band gap energies than that of TiO2-P25. However, ZnO–TNT has shown considerable increase in photo-activity for degradation of RhB dye in visible light as compared to UV light irradiation.

Facile Synthesis of Graphene/ZnO Composite as an Anode with Enhanced Performance for Lithium Ion Batteries

Graphene/ZnO composites with different contents of ZnO have been successfully synthesized via a liquid phase route. The structure, morphology, and electrochemical performances of the composites are investigated by XRD, Raman, SEM, TEM, AFM, and electrochemical measurement. The results reveal that ZnO nanoparticles wedged on the surface of the graphene nanosheets. The initial capacity of graphene/ZnO (1 : 1) reached 1155.27 mAh g−1, which increased 162.87 mAh g−1 compared with the initial capacity of graphene. This could be attributed to the unique structure of the prepared composite and synergies of graphene and ZnO in the lithium ion storage.

Raman and Impedance Spectroscopy of Blend Polycarbonate and Zinc Oxide Layers Grown by Sol-Gel Method

Confocal Raman spectroscopy has been applied to investigate blend polycarbonate and ZnO thin layers with different thicknesses and different content of ZnO. The admittance spectroscopy have been applied to correlation of optical and electrical properties of these layers used in electroluminescence diodes and photovoltaic cells. The I-V (DC and AC) characteristics and thermally stimulated current (TSC) have been applied to the study of the deep levels in ZnO thin films grown by sol-gel method onto Si substrates. The surface spectroscopy morphology of the samples were investigated by scanning microscopy and X ray diffraction.

Preparation and Research on Luminescent Properties of Eu-Doped TiO<sub>2</sub>-ZnO Composite Powders

The Eu-doped TiO2 nanocrystals with different content of Eu3+ and the Eu-doped TiO2-ZnO composite powders with different content of ZnO were prepared by sol-gel method. The X-ray diffraction (XRD) spectra and photoluminescence(PL) spectra indicated that all of the Eu-doped TiO2 have anatase structure. It indicated that the incorporation of Eu3+ can inhibit the transformation of TiO2 from anatase to rutile phase. With the increase of the content of Eu3+, the luminous intensity first increased and then decreased, and luminescent properties were best when the content of Eu3+ is 1.1%. Considering the Eu-doped TiO2-ZnO composite powders, with the increasing of the proportion of ZnO, a Zn2TiO4 phase has been gradually generated. When the content of ZnO up to 40%, the luminescent properties are the best.

Solution blowing of ZnO nanoflake-encapsulated carbon nanofibers as electrodes for supercapacitors

A facile spinning-based strategy is developed to fabricate zinc oxide nanoflake-encapsulated carbon nanofibers (ZnO/CNFs) as electrodes for supercapacitors. The zinc oxide/carbon nanofiber mats were solution blown with zinc acetate (Zn(Ac)2) and polyacrylonitrile (PAN) as the metal and carbon precursor to get Zn(Ac)2 core-enriched precursor nanofibers. After annealing under nitrogen, the precursor nanofibers were converted to ZnO/CNFs with ZnO nanoflakes encapsulated in the core of carbon nanofibers. In the constructed architecture, carbon nanofibers can avoid the direct exposure of ZnO to the electrolyte and preserve the structural and interfacial stabilization of ZnO nanoflakes. Meanwhile, the flexible entangled carbon nanofibers can accommodate temperate porosities thus providing the pore channel for electrolyte ions and maintain the structural and electrical integrity of the ZnO/CNF electrode during the charge–discharge processes. By loading different contents of ZnO, the microstructures of CNFs were changed, and the textural parameters significantly affected their electrochemical properties as electrodes. As a result, the ZnO/CNF electrodes exhibit high specific capacitance (216.3, 212.7, 208.8 and 172.5 F g−1 at 1, 5, 10, and 50 A g−1, respectively) and extremely excellent cycling performance at high current density (only 5.41% capacitance loss after 2000 cycles at a high rate of 10 A g−1), with promising energy densities of 29.76 kW h kg−1, over a power density range of 2.5–30 kW kg−1. The ZnO/CNFs simultaneously exhibit excellent capacity retention. These encouraging results indicate great potential applications of ZnO/CNFs in developing energy storage devices with high energy and power densities.

Effects of ZnO and CeO2 additions on the microstructure and dielectric properties of Mn-modified (Bi0.5Na0.5)0.88Ca0.12TiO3 ceramics

The effects of ZnO and CeO2 on the microstructure and dielectric temperature characteristics of the Mn-modified (Bi0.5Na0.5)0.88Ca0.12TiO3 ceramics were investigated to develop temperature-stable dielectric ceramics. By adding 1–2 wt% ZnO, the overall dielectric constant increased. With further increasing the amount of ZnO, the dielectric constant at temperatures lower than 25 °C decreased, whereas the dielectric constant at temperatures higher than 75 °C increased. The temperature characteristic of capacitance became flatter when more than 4 wt% ZnO was doped. By adding CeO2, the dielectric constant decreased and a flat temperature characteristic of permittivity was obtained. X-ray diffraction analysis revealed that the perovskite BNT phase formed for all the compositions and the secondary phases Zn2TiO4 and Bi2Ti2O7 occurred, respectively when ZnO and CeO2 was added. Scanning electron microscope indicated that an inhomogeneous microstructure comprising fine and rectangle grains was observed in the ZnO-free sample. ZnO less than 2 wt% could inhibit the grain growth and decrease long grains. However, the grain growth was promoted as more than 8 wt% ZnO was added. The dielectric loss with different contents of ZnO and CeO2 were characterized as the function of temperatures for potential use at high temperature. The dielectric loss at 25 °C was independent of the amounts of ZnO and CeO2. However, the dielectric loss at 250 °C decreased by adding 1 wt% ZnO and then increased with increasing ZnO. This system is considered to be a potential material for high-temperature capacitors.

Preparation and ethanol sensing properties of the superstructure SnO2/ZnO composite via alcohol-assisted hydrothermal route

Self-assembled superstructure of SnO2/ZnO composite was synthesized by using alcohol-assisted hydrothermal method gas sensing properties of the material were investigated by using a static test system. The structure and morphology of the products were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM). The diameter of the SnO2 nanorods was about 40 nm with a length of about 300 nm, SnO2 nanorods and ZnO nanosheets interconnect each other to form a superstructure. The gas sensing properties of superstructure SnO2/ZnO composite with different content of ZnO were investigated. Furthermore, the superstructure SnO2/ZnO composite sensor is characterized at different operating temperatures and its long-term stability in response to ethanol vapor is tested over a period of 3 months.

Influence of ZnO and P2O5 Content on Modified HZSM-5 on Aromatization of FCC Gasoline

Catalytic properties of different content of ZnO and P2O5 supported on HZSM-5 zeolites were studied in the conversion of FCC gasoline (75°C–120°C) into aromatic hydrocarbons with a temperature of 430°C, a liquid hourly space velocity of 1.0 hr−1, and a pressure of 0.1 MPa. In the reaction, when the contents of ZnO and P2O5 are 2% and 4%, respectively, Zn-P/HZSM-5 showed the highest selectivity and activity to aromatic hydrocarbons and conversion of olefins. The content of aromatics in the liquid product and the yield of aromatics reached as high as 94.53%, 68.87%, and 51.74%, respectively.