Incorporation Of ZnO Research Articles

Photocatalytic degradation of diclofenac using hybrid MIL‐53(Al)@TiO2 and MIL‐53(Al)@ZnO catalysts

AbstractIn this work, TiO2 and ZnO were incorporated successfully into a MIL‐53(Al) metal–organic framework (MOF) to form nanocomposites via a facile post‐modification technique. The hybrid MIL‐53(Al)@TiO2 and MIL‐53(Al)@ZnO were characterized by several characterization tests. The X‐ray diffraction (XRD), Fourier‐transform infrared (FTIR), and field‐emission scanning electron microscopy (FE‐SEM) analyses showed evidence of the successful incorporation of TiO2 and ZnO within the MIL‐53(Al) framework. The thermal gravimetric analysis (TGA) analysis demonstrated the excellent thermal stability of MIL‐53(Al)@TiO2 and MIL‐53(Al)@ZnO, while diffuse reflectance spectroscopy (DRS) determined the direct optical band gaps of MIL‐53(Al)@ZnO and MIL‐53(Al)@TiO2 to be 3.24 and 3.34 eV, respectively. The composites were also tested for the photocatalytic degradation of diclofenac (DCF) as a micropollutant. The DCF degradation efficiency of the photocatalysts was ranked in the following order: MIL‐53(Al)@TiO2 > MIL‐53(Al) > TiO2 > ZnO > MIL‐53(Al)@ZnO. The incorporation of TiO2 enhanced the optical properties of MIL‐53 (Al), which was confirmed with the superior photodegradation efficiency of MIL‐53(Al)@TiO2 (>85% in 2 h) as compared to the pristine MIL‐53(Al) (around 80% in 2 h). The improvement in the photodegradation of the hybrid‐MOF is mostly associated with the possible dual function of the adsorption and photodegradation mechanisms. The reusability of MIL‐53(Al) and its composites was inspected over 3 cycles of photodegradation experiments with DCF. The photocatalytic activity of MIL‐53(Al)@TiO2 remained unchanged (>90%), while for MIL‐53(Al) and MIL‐53(Al)@ZnO a slight drop was observed over three cyclic degradation experiments. Fluorescence measurements revealed that the hydroxyl radical is an important reactive oxygen species produced by all the photocatalysts that aid in the photodegradation of DCF. Furthermore, the kinetic modelling of the photoreaction identified a second‐order kinetics for all catalysts. Experiments with scavengers showed that hydroxyl radicals played a major role in the photocatalytic process, and it was found that only 2 h of treatment was sufficient to obtain a considerable chemical oxygen demand (COD) reduction of 58%.

Preparation and catalytic properties of ZnO/ Na0.5Bi0.5TiO3 composites

ZnO/Na0.5Bi0.5TiO3 composites were prepared by chemical hydrothermal deposition and hydrothermal method and the effects of ZnO adding on the properties of Na0.5Bi0.5TiO3 were investigated. The results show that the ZnO/Na0.5Bi0.5TiO3 composite with 5% ZnO content has the best photocatalytic performance and good cycling stability. Under simulated sunlight irradiation, the degradation rate for MB (10 mg/L) by ZnO/Na0.5Bi0.5TiO3 composites reached 100% within 20 minutes, and the reaction rate constant was 0.07427min−1, which were 27.51 and 6.00 times higher than those of Na0.5Bi0.5TiO3 (NBT, 0.0027 min−1) and ZnO (0.01237min−1), respectively. The incorporation of ZnO on the Na0.5Bi0.5TiO3 can form Z-scheme heterostructure ZnO/Na0.5Bi0.5TiO3 and increase the specific surface area, inhibiting the recombination of electron and hole and improving separation and transfer carriers efficiency. ZnO/Na0.5Bi0.5TiO3 composites have potential applications in high-efficiency and high-activity photocatalysts to degrade organic pollutants.

A novel synergistic effect of TiO2 and ZnO incorporation in PES-based thin-film nanocomposite nanofiltration membrane for treatment of textile wastewater.

A novel synergistic effect of TiO2 and ZnO incorporation in the PES-based thin-film nanocomposite nanofiltration membranes was developed for the treatment of common effluent treatment plant (CETP) textile wastewater. PES@TiO2 membranes were developed by phase inversion via the immersion precipitation method followed by the addition of zinc oxide nanoparticles prepared by the rapid microwave-assisted hydrothermal process via interfacial polymerization. p-Phenylenediamine was used as a monomer for the IP process that was coated on the PES@TiO2 support layer. Various techniques have been applied to characterize the developed thin-film nanocomposite membranes such as Fourier transform infrared (FTIR) microscopy, field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), and contact angle measurement to examine the presence of vibrational modes, surface morphology, the crystal structure of nanoparticles, and hydrophilicity of the membrane, respectively. Membrane properties include porosity, salt rejection, mean pore radius, pure water flux, and industrial effluent rejection efficiency that were studied. The thin-film nanocomposite membrane T5-PES@TiO2(2%)-ZnO(0.3%) was prepared with a combination of 17 wt% PES, 78 wt% DMF, 3 wt% PVP K30, 2% TiO2, 2.5 wt% PPD, 0.3 wt% ZnO, and 1.0 wt% TMC that exhibited high water permeability, porosity, higher industrial effluent rejection, and salt rejection efficiency compared to the neat PES membrane.

Changes in the structural and optical properties due to the incorporation of ZnO into cerium−cupric sodium borate glasses

Changes in the structural and optical properties due to the incorporation of ZnO into cerium−cupric sodium borate glasses

Siliceous termite hill supported ZnO-TiO2 as a solar light responsive photocatalyst: Synthesis, characterization and performance in degradation of methylene blue dye

Colored contaminants in wastewater need to be removed prior to discharge due to their negative impacts on public health and the environment. Herein, immobilized TiO2 on termite hill (TiO2/TH) and ZnO-promoted TiO2/TH (ZnO-TiO2/TH) were synthesized, evaluated by different characterization techniques (XRF, XRD, FTIR, UV-Vis DRS, N2 adsorption-desorption analysis and SEM), and the possibility of using them as photocatalysts for methylene blue (MB) degradation under solar irradiation investigated. The influence of photocatalytic reaction parameters (initial MB concentration, photocatalyst dosage and solution pH) was studied at fixed irradiation time. XRD and SEM results, among other analyses revealed successful incorporation of ZnO and TiO2 on structured support (TH), while UV-Vis analysis affirmed reduction in band gap energy due to immobilizing effect. The optimized photocatalytic degradation variables were 50 mg/L dye concentration, 1.2 g/L photocatalyst dosage and 6.0 pH. The ZnO-TiO2/TH showed better photoactivity for MB degradation than TiO2/TH under the same conditions which could be attributed to a reduction in band gap energy from 2.94 eV to 2.85 eV upon addition of ZnO. More than 80% degradation efficiency was achieved after the 7th cycle, depicting better stability. A pseudo-first-order Langmuir-Hinshelwood model with a rate constant of 0.0774 min−1 and R2 of 0.9971 at optimum dye concentration (50 mg/L) appeared to best describe the photocatalytic degradation kinetic data. The UV-Vis spectra changes and decrease in total organic carbon indicated that ZnO-TiO2/TH photocatalyst has the prospect to degrade organic pollutants in industrial effluent completely.

Preparation of a biodegradable chitosan packaging film based on zinc oxide, calcium chloride, nano clay and poly ethylene glycol incorporated with thyme oil for shelf-life prolongation of sweet cherry

This study includes development of chitosan-based films with incorporated essential thyme oil and different combinations of cross-linkers viz., ZnO, CaCl2, NC, and PEG for the safe storage of sweet cherries. The resulting films stored with sweet cherries were analyzed for different physicochemical and antimicrobial properties. Incorporation of ZnO, CaCl2, NC, and PEG in chitosan-based films maintained fruit quality by conserving higher total soluble solids, titratable acidity, and reduced weight loss. The combined ZnO + CaCl2 + NC + PEG in chitosan-based films also suppressed microbial activity. The sensorial quality of fruits stored with CH + ZnO + CaCl2 + NC + PEG treatment was also stable during storage. In conclusion, the combined CH + ZnO + CaCl2 + NC + PEG with added thyme oil application is an effective approach to maintain the postharvest quality and could be an alternative to increase the shelf life of sweet cherries, besides decreasing environmental impacts of non-biodegradable packages.

The Effect of Zinc Oxide Supported on Gelatin Mesoporous Silica (GSBA-15) on Structural Character and Their Methylene Blue Photodegradation Performance

Gelatin mesoporous silica SBA-15 (GSBA-15) with rod-like morphology has been successfully synthesized by hydrothermal method using P-123:gelatin, then aged at 90 °C for 24 h and calcined at 550 °C for 5 h. GSBA-15 was impregnated with ZnO amounts of 1; 5; and 10 wt% to obtain Zn/GSBA-15. Samples were characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller (BET). The efficiency of methylene blue photodegradation was determined by a UV-Vis spectrophotometer. The FTIR result is functional groups of ZnO/GSBA-15, those were Si−O−Si, −OH, Zn−OH, and Zn−O. The morphology of ZnO/GSBA-15 was rod-like, and it consisted of silica, oxygen, and Zn. The surface area and pore volume of GSBA-15 declined (surface area from 520.8 to 351.9 m2/g and pore volume from 0.707 to 0.564 cm3/g) after ZnO impregnation due to pore blocking. At the same time, increasing pore diameter (from 2.82 nm to 3.19 nm) and crystallite size (from 5.1 nm to 12.6 nm) were observed due to the overlapping of ZnO-Silica particles. The increasing incorporation of ZnO on the silica GSBA-15 framework increases the photodegradation performance from 88.76% to 94.90% due to the high surface area, functional group rich, and dispersion of ZnO active sites. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Removal of Cr(VI) from aqueous solution by a novel ZnO-sludge biochar composite.

The incorporation of ZnO into biochar has become a promising way to obtain adsorbents with enhanced adsorption capacity. In this study, a low-cost ZnO-sludge biochar composite (ZBC) was prepared by a simply in situ method using sewage sludge biochar (SBC) and zinc acetate, as well as employed for Cr(VI) adsorption in water. The results of XPS and FT-IR suggested that the ZBC surface had more functional groups such as -COOH, -OH, -C-O, ZnO, etc. Compared with SBC, the BET-specific surface area of the ZBC increased from 8.82 to 41.24 m2·g-1, which provides potential advantages for Cr(VI) uptake. Benefiting from ZnO incorporation, about an 18% increase in Cr(VI) removal efficiency was obtained. The maximum removal efficiency and equilibrium adsorption amount of ZBC for Cr(VI) reached 98.4% and 33.87 mg·g-1, respectively. The adsorption was spontaneous and endothermic nature, and coincided nicely with pseudo-second-order kinetics and Langmuir isotherm. The analyses indicated that Cr(VI) removal by ZBC was predominantly via electrostatic attraction, surface complexation, ion exchange, and reduction. This study provided valuable insights into the problem of sludge disposal and provided a new and effective method for Cr(VI) removal.

A simple method to improve antibacterial properties in commercial face masks via incorporation of ZnO and CuO nanoparticles through chitosan matrix

In this research, generic surgical face masks were sprayed with a solution of chitosan (CHT) containing ZnO or CuO nanoparticles to improve its performance against pathogens. The modified face masks were studied by infrared spectroscopy, UV–vis and electronic microscopy. The analysis confirmed the face masks are made of polypropylene, and the formation of microfilms of CHT containing either ZnO or CuO over the fibers was also observed. The modified face masks were immersed in water, and the extracts were analyzed by means of inductively coupled plasma optical emission spectrometry. Traces of metallic ions were not detected, showing thus that the interaction nanoparticle/polymeric matrix-fiber is stable as the generated microfilms remain over the fiber even in highly humid environment. The ZnO/CHT and CuO/CHT exhibited good performance against Staphylococcus aureus and Escherichia coli, with CuO/CHT being the most promising additive. Finally, the modification of face masks did not produce any adverse effect in the biocompatibility of face masks. Therefore, this method is easy and can be applied to commercial face masks to improve the performance against pathogens.

A Research on Delayed Thermal Depolarization, Electric Properties, and Stress in (Bi0.5Na0.5)TiO3-Based Ceramic Composites.

Depolarization behavior is one of the main shortcomings of (Bi0.5Na0.5)TiO3-based ceramics. Considering the undesirable efficiency of traditional modification methods, in this paper a series of 0–3 type ceramic composites 0.85(Bi0.5Na0.5)TiO3-0.11(Bi0.5K0.5)TiO3-0.04BaTiO3-x mol% ZnO (BNKT-BT-xZnO)) were synthesized by introducing ZnO nanoparticles. The results of the X-ray diffraction pattern (XRD) and energy dispersive spectroscopy (EDS) demonstrate that the majority of ZnO nanoparticles grow together to form enrichment regions, and the other Zn2+ ions diffuse into the matrix after sintering. With ZnO incorporated, the ferroelectric–ergodic relaxor transition temperature, TF-R, and depolarization temperature, Td, increase to above 120 °C and 110 °C, respectively. The research on temperature-dependent P–E loops verifies an attenuated ergodic degree induced by ZnO incorporation. For this reason, piezoelectric properties can be well-maintained below 110 °C. The electron backscatter diffraction (EBSD) was employed to investigate the stress effect. Orientation maps reveal the random orientation of all grains, excluding the impact of texture on depolarization. The local misorientation image shows that more pronounced strain appears near the boundaries, implying stress is more concentrated there. This phenomenon supports the hypothesis that potential stress suppresses depolarization. These results demonstrate that the depolarization behavior is significantly improved by the introduction of ZnO. The composites BNKT-BT-xZnO are promising candidates of lead-free ceramics for practical application in the future.

Single Solid Precursor-Derived Three-Dimensional Nanowire Networks of CuZn-Silicate for CO2 Hydrogenation to Methanol

Hydrogenation of CO2 to MeOH is one of the most promising technologies in mitigating the emissions of CO2 and tackling the challenge of climate change. In this work, we present a synthetic protocol for preparing a Cu–ZnO-based heterogeneous catalyst supported by siliceous nanowire networks from a single solid precursor with a tunable composition. The resulting Si–Cu–Zn catalysts were evaluated with the MeOH synthesis from the CO2 hydrogenation reaction operated at moderate conditions (30 barg and 200–280 °C). A specific MeOH yield of 402 mgMeOH·gCu–1·h–1 and a MeOH selectivity of 51% were obtained at 240 °C. Such a performance was attributed to several structural and compositional merits, granted through the attentively engineered synthetic procedures. Small Cu nanoparticle (NP) size was achieved and maintained by the high dispersion of Cu to the atomic level in the precatalyst and the incorporation of ZnO as a structural promoter. Moreover, the desirable Cu–ZnO synergistic effect can be further attained from the strong metal–support interaction (SMSI) between the Cu NPs and the partially reduced ZnO phase. Lastly, the robust siliceous nanowire networks provided decent spatial confinement to contain the growth of Cu NPs while offering high accessibility with the macroscopic porous morphology. The catalyst exhibited stable performance over a week’s long stability test while keeping its structural integrity intact. Overall, this study may offer an alternative design and synthesis strategy for the well-received Cu–ZnO system to approach its high performance in CO2 hydrogenation.

Supercapacitive properties, optical band gap, and photoluminescence of CeO2–ZnO nanocomposites prepared by eco-friendly green and citrate sol-gel methods: A comparative study

CeO2–ZnO nanocomposite was synthesized using a cost-effective and environmentally friendly green method utilizing a natural extract of Hibiscus Sabdariffa L. The structural parameters, morphology, optical, and supercapacitive properties of a novel green sol-gel synthesized CeO2–ZnO nanocomposite (CZO-g) were compared with those of a citrate sol-gel auto-combustion derived nanocomposite (CZO-s). XRD confirmed the formation of cubic and wurtzite hexagonal binary phases, and CZO-g exhibited better crystallinity than CZO-s. ZnO incorporation inhibits the accumulation of CeO2 semispherical NPs, as demonstrated by FESEM images. DRS and PL emission measurements confirmed that the optical band gap of nanocomposites was widened. CV, GCD and EIS measurements were used to determine the electrochemical supercapacitive behavior of nanomaterials deposited on Ni Foams in a 3 M KOH electrolyte. At a current density of 1 A g−1, CZO-g exhibited significantly greater specific capacitance (431 F g−1) than CZO-s and CeO2-g. Furthermore, CZO-g retained 89.4% of its initial capacitance after 3000 cycles at a high current density of 7 A g−1, indicating that it could be a promising candidate for a high-performance supercapacitor.

Biocompatibility and antibacterial behavior of electrochemically deposited Hydroxyapatite/ZnO porous nanocomposite on NiTi biomedical alloy

In this article, Hydroxyapatite (HA) and its composite with ZnO nanoparticles were electrochemically deposited on NiTi superelastic alloy to evaluate the effect of nanoparticles on its various properties. Morphological observations revealed that the addition of 400 mg/L ZnO nanoparticles created an HA layer with a porous network structure. FTIR and GIXRD results pointed out that the nanoparticles contributed to pure HA synthesis. Given AFM topography parameters, a significant rise was detected in roughness values as ZnO entered the HA matrix. The rough surface with a larger volume of porosity improved the wettability of the composite coating by reducing the contact angle to approximately half of its initial value (14.57°). Furthermore, ZnO incorporation proved to be quite helpful in contact with living species. Cell culture assessments disclosed the considerable impact of ZnO nanoparticles on MG-63 osteoblast-like cells’ attachment and proliferation on the composite coating. They also improved cell viability reported by the MTT assay. The antibacterial resistance of HA and HA/ZnO coatings was investigated against E. Coli and S. Aureus bacteria colonies by the disk diffusion method. For the first time, the pure HA matrix showed antibacterial activity, though insignificant. The addition of ZnO nanoparticles promoted this behavior which was more vigorous in the case of S. Aureus bacteria.

Single-burn clinkering of endodontic calcium silicate-based cements: Effects of ZnO in the C3S phase formation and hydration rate

Calcium silicate-based cements were synthesized with 1–4 wt% ZnO at 1300 and 1500 °C. Powder and in-situ XRD tests were conducted in anhydrous and hydrating samples. Results showed that ZnO addition significantly increased the alite (C3S) content into cements, thus allowing the single-burn clinkering of cement with over 80 wt% C3S. ZnO incorporation progressively reduced the relative content of triclinic C3S while increasing the monoclinic C3S content. No significant hydration delays were observed when ZnO was added up to 1 and 3 wt% for the cement synthesized at 1300 and 1500 °C, respectively. ZnO proved to be an efficient mineralizer even in a single-burn step and does not seem to retard the C3S hydration when incorporated into its structure.

Improved mechanical properties of AgTiB2 contact materials reinforced by the TiB2 loaded with ZnO nanorods

The TiB2 loaded with nano-sized ZnO rods were synthesized by sol-gel method, and the Ag-4wt.%TiB2-xwt.%ZnO (x = 0, 0.25, 0.5) contact materials were fabricated by spark plasma sintering (SPS). The results revealed that the ZnO nanorods with the dimensions of about Φ130 × 400 nm were uniformly loaded on the surface of TiB2 particles. The incorporation of ZnO can inhibit the aggregation of TiB2 reinforcements and promote the densification of AgTiB2 composites. As compared to Ag-4wt.%TiB2, the Ag-4wt.%TiB2-0.25wt.%ZnO contact material presents a larger increase on the yield strength and ultimate compressive strength, which is increased by 247.93% and 111.58%, respectively. It suggests that an appropriate ZnO content is more beneficial for the improvement on the mechanical properties of AgTiB2 contact materials.

Zinc Oxide and Copper Chitosan Composite Films with Antimicrobial Activity.

The role of the oral microbiome and its effect on dental diseases is gaining interest. Therefore, it has been sought to decrease the bacterial load to fight oral cavity diseases. In this study, composite materials based on chitosan, chitosan crosslinked with glutaraldehyde, chitosan with zinc oxide particles, and chitosan with copper nanoparticles were prepared in the form of thin films, to evaluate a new alternative with a more significant impact on the oral cavity bacteria. The chemical structures and physical properties of the films were characterized using by Fourier transform infrared spectroscopy (FTIR,) Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and contact angle measurements. Subsequently, the antimicrobial activity of each material was evaluated by agar diffusion tests. No differences were found in the hydrophilicity of the films with the incorporation of ZnO or copper particles. Antimicrobial activity was found against S. aureus in the chitosan film crosslinked with glutaraldehyde, but not in the other compositions. In contrast antimicrobial activity against S. typhimurium was found in all films. Based on the data of present investigation, chitosan composite films could be an option for the control of microorganisms with potential applications in various fields, such as medical and food industry.

Enhancing the visible-light photoactivity of silica-supported TiO2 for the photocatalytic treatment of pharmaceuticals in water.

Catalyst samples based on SiO2-supported TiO2 were prepared with the incorporation of Ag (metal), S (nonmetal), and ZnO@S (semiconductor and nonmetal). The materials were evaluated regarding their morphological, optical, and crystalline properties as well as their photoactivity under visible and ultraviolet light toward the degradation rate of a model emerging pollutant, acetaminophen (ACT). All modified materials exhibited improved performance over the undoped catalyst. The Ag-doped catalyst achieved the largest degradation under visible radiation (about 30% in 120 min), whereas under ultraviolet irradiation, the ZnO@S-doped sample exhibited the best performance (about 62% in 120 min). A Doehlert design was carried out to evaluate the influence of pH and temperature on the photoactivity of Ag-TiO2/SiO2. In addition, the role of each reactive species in the photodegradation reaction was investigated by radical scavenger experiments, and the superoxide radical anion O2•- was shown to be the predominant reactive species. The stability of the Ag-TiO2/SiO2 material under ultraviolet and visible light was confirmed after five successive operation cycles, showing a reasonable (about 50%) loss of activity under visible irradiation and a slight improvement (about 13%) under UV light, as a result of the photo-reduction of Ag+. Lastly, the effect of the initial pollutant concentration showed that ACT degradation using Ag-TiO2/SiO2 follows the Langmuir-Hinshelwood kinetics, with intrinsic reaction rate k = 2.71 × 10-4 mmol L-1 min-1under visible-light radiation.

Optimization of ZnO incorporation to αFe2O3 nanoparticles as an efficient catalyst for biodiesel production in a sonoreactor: Application on the CI engine

Pure αFe2O3 and αFe2O3 1-x/ZnO x (x = 0, 40 and 80 wt%) nanoparticles were synthesized using the sol-gel method and, then, tested for biodiesel production from canola oil with the sonochemical process. Characterization of nanocatalysts was carried out using XRD, BET-BJH, SEM, EDX, TEM, TGA, CO2-TPD, and Raman spectroscopy analyses. The results of CO2-TPD and Raman confirmed that the dispersion of ZnO is well incorporated in the structure of αFe2O3, increasing the basicity of the nanocatalyst via generating oxygen vacancy. The response surface methodology (RSM) and Box behnken design (BBD) were utilized to analyze the effect of parameters. The best incorporation of ZnO on catalytic performance was observed in x = 47.24 wt%. Besides, the size and shape of the optimized nanocatalyst were 40 nm and needle/hexagonal, respectively. The optimization of the reaction demonstrated the maximum biodiesel yield of 94.21%. Reusability investigation of the optimum catalysts even after seven consecutive cycles revealed that αFe2O3/ZnO nanoparticles have higher catalytic performance and are more stable than pure αFe2O3. The results of the engine test indicate that the rich oxygen amount of canola biodiesel leads to considerable improvements in fuel combustion conditions, particularly in B30 (30% biodiesel-70% diesel).

Auto combustion synthesis and characterization of Co doped ZnO nanoparticles with boosted photocatalytic performance

In this report, pure ZnO and Co doped ZnO (1, 2.5, 5, 7.5 wt% of Co) nanoparticles were synthesized by using one-pot flash combustion synthesis technique. Structural, morphological, optical and photocatalytic properties of the prepared samples were analyzed by using different characterization techniques. The X-ray diffraction results shows the pure ZnO and Co:ZnO samples exhibits hexagonal wurtzite structure having preferential growth along the (101) plane without the presence of secondary phase impurities. The crystalline size of the 7.5% Co:ZnO sample was found to be higher with a value of 27.14 nm with low dislocation density and strain values of 1.36 × 10−3 and 4.38 × 10−3, respectively compared to the other prepared samples. The morphology of the prepared samples were obtained using FESEM analysis which revealed a non-uniform spherical shaped nanoparticles for pure ZnO and the morphology becomes uniform with the incorporation of the Co dopants. The e-mapping and the EDX results confirms the presence of Zn, O and Co elements. UV–Vis. absorption spectrum revealed that the inclusion of Co dopants in ZnO incorporation leads to higher absorption and decrease in band gap. The band gap values of ZnO are noticed to be reduced from 3.27 eV 2.81 eV with Co doping from 0 to 7.5 wt%. Photocatalytic performance of the prepared samples was evaluated in the decolourization reaction of methyl green aqueous solution under the illumination. The prepared Co doped ZnO samples exhibited several times higher photocatalytic activity than bare ZnO. The kinetic model was proposed and the rate constant for the decolourization reactions was calculated. The best performed sample was 5 wt% Co, in which the rate constant was 2.6 times higher than that of bare ZnO.

Incorporation of ZnO–ZrO2 nanoparticles into TiO2 coatings obtained by PEO on Ti–6Al–4V substrate and evaluation of its corrosion behavior, microstructural and antibacterial effects exposed to SBF solution

In this research, Plasma Electrolytic Oxidation technique was used to incorporate ZnO–ZrO2 nanoparticles into TiO2 ceramic coating on Ti6–Al–4V using sodium phosphate as an electrolyte. The effect of adding these nanoparticles on corrosion, morphology, wettability and antibacterial properties in the simulated body fluid (SBF) solution was investigated. The results indicated nanoparticles modified the microstructure of coating, which increased corrosion resistance 12 times higher than that of substrate. Besides, ZrO2 nanoparticles had the most significant effect on increasing the contact angle. In addition, due to the compatibility of zirconium and zinc oxides with human body environment, the antibacterial properties of coatings were significantly improved.