ZnO Products Research Articles

Synthesis and Catalytic Performance of Bimetallic Oxide-Derived CuO-ZnO Electrocatalysts for CO2 Reduction.

Steering the selectivity of electrocatalysts toward the desired product is crucial in the electrochemical reduction of CO2. A promising approach is the electronic modification of the catalyst's active phase. In this work, we report on the electronic modification effects on CuO-ZnO-derived electrocatalysts synthesized via hydrothermal synthesis. Although the synthesis method yields spatially separated ZnO nanorods and distinct CuO particles, strong restructuring and intimate atomic mixing occur under the reaction conditions. This leads to interactions that have a profound effect on the catalytic performance. Specifically, all of the bimetallic electrodes outperformed the monometallic ones (ZnO and CuO) in terms of activity for CO production. Surprisingly, on the other hand, the presence of ZnO suppresses the formation of ethylene on Cu, while the presence of Cu improves CO production of ZnO. In situ X-ray absorption spectroscopy studies revealed that this catalytic effect is due to enhanced reducibility of ZnO by Cu and stabilization of cationic Cu species by the intimate contact with partially reduced ZnO. This suppresses ethylene formation while favoring the production of H2 and CO on Cu. These results show that using mixed metal oxides with different reducibilities is a promising approach to alter the electronic properties of electrocatalysts (via stabilization of cationic species), thereby tuning the electrocatalytic CO2 reduction reaction performance.

Trichoderma and Mycosynthesis of Metal Nanoparticles: Role of Their Secondary Metabolites.

Nanocompounds are widely used in many fields such as environmental, medicine, or agriculture. Nowadays, these nanocompounds are mainly synthesized by chemical methods, causing environmental pollution and potential health problems. Thus, microorganisms have been investigated as potential nanoparticle green biosynthesizers. The main research is focused on the synthesis of nanoparticles (NPs) using algae, yeast, bacteria, and fungi. Among them, fungi have been the most used, due to their simple and effective mycosynthesis. Fungi as well as other organisms involved in green synthesis of NPs use their secondary metabolites (SMs) to mediate and catalyze the reactions to produce metal nanoparticles (MNPs) as well as being able to act as capping agents producing different physicochemical characteristics and biological activities in the MNPs. Among the various fungi used for mycosynthesis are Trichoderma species, which mediate the production of Ag, Cu, CuO, Zn, ZnO, and other MNPs. Here, we review the main SMs from Trichoderma that have been reported or suggested to contribute to synthesize or act as capping agents and their applications, as well as present the main challenges faced by this type of synthesis.

Effect of volume ratios on the novel Solanum lycopersicum leaf extract-mediated production of ZnO and Co3O4 nanoparticles for potential antifungal applications

ABSTRACT Antimicrobial infectious disease has become a major problem in the world. It has been found as its continual distribution is at extremely frightening rate. The most curable technique is the design and synthesis of effective nano-based drugs as green alternative. In this study, ZnO and Co3O4 nanoparticles (NPs) were produced from their precursor salts in the volume ratios of 1:3, 1:1, and 3:1 with Solanum lycopersicum leaf as a capping and reducing agent. Characterizations were performed using TGA/DTA, XRD, SEM, TEM, HRTEM, SAED, UV-Vis, and FTIR techniques. After 450°C and 500°C, ZnO and Co3O4 NPs were found to be thermally stable, respectively. For the ZnO and Co3O4 NPs in 1:3, 1:1, and 3:1 volume ratios, respectively, their average crystalline sizes were 51, 20, 29 and 26, 21 and 28 nm. The degree of crystallinity is confirmed by SEM in conjunction with TEM-HRTEM, and SAED. Among the numerous volume ratios, Co3O4 (1:3) and Co3O4 (1:1) showed 100% promised activity against Alternaria solani pathogen. Antimicrobial infectious disease has become a major serious problem in the modern world. It has been found as its continual distribution is at an extremely frightening rate. The most curable technique for this worldwide issue is the design and synthesis of effective nano-based drugs as green alternative solutions. In this study, ZnO and Co3O4 nanoparticles (NPs) were produced from their respective precursor salts in the volume ratios of 1:3, 1:1, and 3:1 with Solanum lycopersicum leaf as a capping and reducing agent. Characterizations were performed using TGA/DTA, XRD, SEM, TEM, HRTEM, SAED, UV-Vis, and FTIR techniques. After 450°C and 500°C, greenly synthesized ZnO and Co3O4 NPs were found to be thermally stable, respectively. For the ZnO and Co3O4 synthesized in 1:3, 1:1, and 3:1 volume ratios, respectively, their average crystalline sizes were 51, 20, 29 and 26, 21 and 28 nm. The degree of crystallinity is confirmed by SEM examination in conjunction with TEM-HRTEM, and SAED. Among the numerous volume ratios, Co3O4 (1:3) and Co3O4 (1:1) showed 100% promised activity against Alternaria solani pathogen.

Enhancing the efficiency of the organic-inorganic hybrid perovskite cells using Al-doped ZnO as an Electron Transport Layer and CNTs as a Hole Transport Layer: An experimental and numerical study

Perovskite solar cells (PSCs) have become the subject of much discussion in the photovoltaic field due to their excellent performance over the past few years. This study presents the production, characterization, and simulation of Al-doped ZnO (AZO) as an electron transport layer (ETL) at a concentration of 1% in organic-inorganic hybrid perovskite solar cells (PSC). We experimentally elaborate the AZO thin films using the sol-gel dip-coating method. We further examined the resulting film for structural, morphological, and optical properties for use in solar cells (SCs), using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and UV–visible spectroscopy. Furthermore, this work presents an optimization process led by simulation that generates high performance using CNTs, CH3NH3PbI3, and AZO as a hole transport layer (HTL), absorber layer, and ETL respectively in solar cells using SCAPS 1D software. We have carefully examined the impact of several parameters, including the layer thicknesses, temperature, defect density of the absorber layer, defect density at interfaces between AZO and perovskite and perovskite and CNTs, and series and shunt resistances (Rs and Rsh). An optimized PSC of ITO/AZO/MAPbI3/CNTs/Au is designed here with an efficiency of 25.62%, open-circuit voltage (Voc) of 1.3955 V, fill factor (FF) of 72.32%, and current density (Jsc) of 25.382 mA/cm2. Our findings provide a remarkable efficiency using the proposed model; nevertheless, as researchers, we still need to simulate and conduct experiments to increase the cell's efficiency to potentially use it in solar cells(SCs).

Synthesis, characterization of Gd-doped ZnO nanocrystals and their photocatalytic activity in the degradation of C.I. Acid Red 18

In this study, ZnO and Gd doped ZnO with various weight percentages (1, 2, 3, and 4 wt% Gd calcined at 450 °C and 2 wt% Gd doped ZnO calcined at 450, 550, 650, and 750 °C) have been prepared. XRD, TEM, DRS, PL measurements, EDX, and FTIR were used for the characterization of the as-prepared photocatalysts. The photocatalytic activity of the as-synthesized ZnO and Gd-doped ZnO products was assessed by AR18 as a model of textile contaminants degraded in water under UV radiation. The effect of operating parameters such as pH, contact time, the initial dye concentration, and the influence of different contents of gadolinium doping and analysis were estimated. We use some active species such as ethanol, K2Cr2O7, KI, and Oxalate to find the photocatalyst and the formation of the electron-hole mechanism of Gd-doped ZnO. After 40 min, the catalyst calcined at 450°C (at pH = 5.0, [AR18] = 1.0 × 10−5M)showed the highest efficiency (98.28 %). The amount of COD decrease after 40 min of irradiation is 98.6 %.

Effect of Ag Doping on ZnO/V2O5 Nanoparticles as a Photo Catalyst for the Removal of Maxillion Blue (GRL) Dye

In this research, the photo catalytic degradation of textile dyes as a model Maxillion Blue (GRL) dye by using Ag/ZnO/V2O5 nanocomposites synthesised via hydrothermal method. The physical properties of the as-synthesised nanocomposites were examined using characterisation techniques such as scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), TEM, and UV-vis spectroscopy. the production of pure ZnO, V2O5 nanoparticles and the discovery, by XRD analysis, of diffraction peaks related to the hexagonal phase of ZnO, V2O5, UV-vis spectroscopic calculations of the nanocomposite’s energy bandgap (2.63 eV) indicated that it might function as a photo catalyst when exposed to UV-visible light. XRD also supported the fabrication of the ZnO/V2O5 nanocomposite. FE-SEM images showed that the object was spherical and somewhat hexagonal in form. EDX analysis reveals the presence of Zn, V, and O in the nanocomposite; its photocatalytic activity was evaluated through the degradation of GRL dye under exposure to solar light. The results showed that the optimum mass nanocomposite for efficient photo degradation was 0.4 g/L, with a degradation efficiency of 91.6%.

Mucor sp. (Fungal Philospheric) of Gambir (Uncaria) Leaf surface as a biosynthetic Mg doped ZnO Nanorods media for antibacterial applications

The antibacterial activity of ZnO nanorods (NRs) has been tested for its ability to inhibit the cells of pathogenic bacteria such as Staphylococcus aureus and Salmonella sp. This study aims to increase the antibacterial activity through modification of Mg2+ doped ZnO morphology under sol-gel-hydrothermal synthesis conditions at pH 10. The mechanism of biosynthetic reactions was using enzymatic grooves of the cell phyllosphere isolate of gambir (Uncaria) leaves as a reducing compound and capping agent. The X-ray diffraction (XRD) analysis showed that ZnO and Mg doped ZnO products were wurtzite structures based on intensities 2θ = 31.78°, 34.43°, 36.27° correlated to hkl (100), (002), (101), respectively (ICSD standard −157724). Mg doped ZnO has the same intensity as the control and no impurity intensity was obtained. Scanning electron microscope (SEM) analysis showed nanospheric morphological patterns, while nanorods have a more dominant size distribution in the range of 125–175 nm. Infrared (FT-IR) analysis at wave numbers 401–584 cm−1 showed a Zn-O stretch. Furthermore, powder ultraviolet (UV-DRS) analysis indicated optical properties based on the uptake on blue-shift regions with λmax ≤ 400 nm and had a change in the bandgap (Eg) of 3.37 eV after conversion using Tauc-plot. The results also showed that the greater the concentration of Mg+2 ions, the smaller the bandgap will be, i.e., of 3.13, eV, 3.10, eV, 3.11 eV, and 3.12 eV for 0, 1, 2, and 3%, respectively. On the antibacterial activity against bacteria Gram (+) Staphylococcus aureus and Gram (–) Salmonella typhi., the largest inhibitory zone was found on Gram (–) bacteria at 24 mm.

Tuning the morphologies of ZnO for enhanced photocatalytic activity

Facile one-pot method to prepare three-dimensional hierarchical nanostructures of ZnO with good control over their morphologies and enhanced photocatalytic activity was developed by proper selection of template, base and microwave irradiation conditions in pure water. Synthesized ZnO products were characterized by XRD, SEM, BET, and TGA. The effect of morphology on the decolorization of rhodamine B solution under UV light irradiation was investigated. The ZnO nanorods originating from the center (Tetrapods) exhibits enhanced photocatalytic activity in the degradation of Rhodamine B under UV light irradiation. This high degradation efficiency (98.86 %) can be attributed to the large percentage of the exposed [1 0 1] facet, (facet dependent) even though surface area is relatively lower. Photocatalytic study reveals that the decomposition of Rhodamine B follows a first order kinetics regardless of the morphology of ZnO particles. The rate constant for nano tetrapods of ZnO particles is the highest (0.036 min−1), while the rate constant for nano coral reefs is lowest (0.003 min−1). Moreover, the photocatalyst exhibits excellent durability, allowing it to be utilized for at least five consecutive cycles without losing its efficiency. Based on the results obtained from two separate synthesis and characterization experiments performed under identical reaction conditions, we can conclude that our material and synthesis protocol exhibit a high degree of reproducibility. This study signifies the dependence of enhanced photocatalytic activity on morphology but not the surface area of material.

One-step cladding metal oxide nanowires with a carbon-dots-embedded ZnO amorphous layer toward boosted photoelectrochemical water oxidation

An effective method was proposed for constructing carbon dots (CDs)-sensitized multijunction composite photoelectrodes via one-step cladding a CDs-embedded ZnO amorphous overlayer on vertically aligned metal oxide nanowires. This strategy involved the double role of hexamethylenetetramine (HMTA) in the ethylene glycol (EG) solvent mixed with a controllable trace amount of water. In the water-deficient synthetic system, a limited portion of HMTA served as the pH buffer and hydroxyl source to force the hydrolytic process of zinc ions for the production of ZnO. The precipitated ZnO clusters were instantly capped by EG molecules through the activated alkoxidation reaction, and further crosslinked into an amorphous network surrounding the individual nanowires. Meanwhile, the excess HMTA was simultaneously depleted as the precursor for producing CDs in the EG solution through thermal condensation, which were packed in the gradually formed aggregates. We revealed that a CDs-embedded amorphous ZnO overlayer with an appropriate proportion of ingredient could be tailored through an optimal tradeoff between hydrolysis and condensation of HMTA. Benefiting from the synergy of the amorphous ZnO layer and the embedded CDs, the multijunction composite photoanodes exhibited significantly improved PEC performance and stability for water oxidation.

PH-Effect in the Fabrication of ZnO Nanostructured Thin Films by Chemical Bath Deposition for Increasing the Efficiency of Solar Cells.

In this study, the impact of pH on the production of ZnO nanostructured thin films using chemical bath deposition was investigated for the purpose of enhancing the efficiency of solar cells. The ZnO films were directly deposited onto glass substrates at various pH levels during the synthesis process. The results indicate that the crystallinity and overall quality of the material were not affected by the pH solution, as observed through X-ray diffraction patterns. However, scanning electron microscopy revealed that surface morphology improved with increasing pH values, leading to changes in the size of the nanoflowers between pH 9 and 11 values. Furthermore, the ZnO nanostructured thin films synthesized at pH levels of 9, 10, and 11 were utilized in the fabrication of dye-sensitized solar cells. The ZnO films synthesized at pH 11 exhibited superior characteristics in short-circuit current density and open-circuit photo-voltage compared with those produced at lower pH values.

Nickel-Doped ZnO Porous Sea Urchin Nanostructures with Various Amounts of Oxygen Defects for Volatile Organic Compound Detection

Porous sea urchin-like nickel-doped ZnO with various nickel contents and high specific surface area were synthesized using a solution method followed by calcination. The nickel-doped ZnO products consisted of numerous porous nanoleaves. The Ni content in these products ranged from 5% to 20%. The Ni dopants in the ZnO lattice were verified by X-ray diffraction and X-ray photoelectron spectroscopy. The sensors based on nickel-doped ZnO sea urchins showed superior sensing performance for some volatile organic compounds (VOCs). ZnO sea urchins with 10% nickel doping exhibited the best gas-sensing performance, including a low working temperature, short response/recovery time, and high sensor response. In particular, the 10% Ni-doped ZnO sea urchin sensor exhibited a response of 84.4 with response/recovery times of 17/20 s towards 100 ppm formaldehyde vapor. These superior sensing behaviors were attributed mainly to a suitable Ni content with high content of oxygen defects, small nanocrystals, and a porous hierarchical structure with a high specific surface area.

Synthesis and optical properties of phosphorus doped ZnO: X-ray absorption, X-ray emission, and X-ray excited optical luminescence studies

Abstract Over the past decades, zinc oxide semiconductor and its derivatives have been extensively developed because of its optoelectronic properties. Since ZnO is an intrinsic n-type semiconductor, how to synthesize high-quality p-type ZnO semiconductors and investigate their optoelectronic properties and local chemical structures are important and necessary. In this article, two studies of synthesizing both undoped and phosphorus-doped ZnO nanostructures by hydrothermal method and chemical vapor deposition (CVD) technique are presented. Scanning electron microscopy (SEM) and laboratory X-ray diffraction (XRD) are used to track the surface morphology and the crystalline structure of both undoped and phosphorus doped ZnO nanostructures, respectively. X-ray absorption near edge structures (XANES), X-ray emission spectroscopy (XES) and X-ray excited optical luminescence (XEOL) are also used to determine the local chemical information of both undoped and phosphorus-doped ZnO nano/microstructures such as local symmetry and optical properties. It is found that the phosphorus is successfully doped into the surface of ZnO and substituted the Zn. The phosphorus-doped ZnO products have better crystallinity and less oxygen vacancies on the surface. These two are correlated as one leads to the other. The XEOL results suggest that the average bandgap for undoped and phosphorus doped ZnO is the same, 3.24 eV. The second derivative of the absorption-emission spectra yields the fundamental bandgap for undoped ZnO and phosphorus-doped ZnO is 3.25 eV. The implication of this observation is discussed.

Synthesis and Characterization of ZnO Doped TiO2 Nanocomposites for Their Potential Photocatalytic and Antimicrobial Applications

As a result of the sol-gel method, we were able to produce pure ZnO and ZnO-doped TiO2 nanocomposites. The hexagonal wurtzite phase in ZnO products was discovered by powder X-ray diffraction (XRD). ZnO products are typically hexagonal wurtzite crystallites, formed according to the Debye Scherrer formula. Nanocomposites with significant morphological changes were created using the sol-gel process, including those that resembled rocks. To determine the composition of Zn, O, and Ti atoms in the samples, a multidimensional X-ray analysis was performed. There is an energy gap between 3.61 eV, as determined by UV-vis spectroscopy. In this study, pure ZnO and ZnO-doped TiO2 nanocomposites were used to study the degradation of methylene blue (MB) under visible light irradiation. Over an irradiation course of 6 h, a ZnO-doped TiO2 composite (84%) were studied. As determined by the kinetic analysis, nanocomposites made from pure ZnO and ZnO-doped TiO2 followed pseudo-first-order kinetics. In the presence of ZnO-doped TiO2 nanocomposites, antibacterial activity was significantly improved. This was shown to be effective against Gram-positive and Gram-negative bacteria (Escherichia coli and B. sublittus). There is evidence that the metal oxide nanocomposites that are produced can be used as an appropriate antimicrobial and disinfection alternative, particularly in biomedical settings, as reported in more detail.

Green synthesis of dual-spinneret electrospun polyacrylonitrile–ZnO@β-cyclodextrin–chitosan nanofibrous nanocomposite as a novel nano-biosorbent

A significant range of intriguing nanomaterials includes photocatalytic and antibacterial nanocomposites, which exhibit great efficacy in water treatment. In this work, Euphorbia hebecarpa extract was used as a novel natural reducing agent to investigate the environmentally friendly production of ZnO@β-cyclodextrin (CD) nanoparticles (NPs). In the following, polyacrylonitrile, ZnO@β-CD and chitosan nanofibers were electrospun concurrently using a dual-electrospinning process to create a unique nano-biosorbent made of polyacrylonitrile (PAN)–ZnO@β-CD–chitosan (CS) nanofibrous nanocomposite. Additionally, this nanocomposite’s effectiveness as a novel photocatalyst and antibacterial agent for eliminating organic dyes like methylene blue was evaluated. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) analysis, Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy (RS) were used to analyze the structure of the nanocomposite. The outcomes verified the production of ZnO@β-CD, which had evenly shaped particles with an average size of 45 nm on the nanofibrous matrix. This nanocomposite exhibited removal efficiency of methylene blue of ~90% after 105 min at pH 7 and 2.5 g L−1 nanocomposite concentration. Furthermore, an antibacterial test revealed that PAN–ZnO@β-CD–CS nanofibrous nanocomposite with 6% ZnO showed over 80% reduction in colony-forming units per millilitre against Bacillus cereus, Staphylococcus epidermidis and Streptococcus iniae.

In Situ Observation of ZnO Nanoparticle Formation by a Combination of Time-Resolved X-ray Absorption Spectroscopy and X-ray Diffraction.

The formation of ZnO nanomaterials from different Zn acetylacetonate precursor solutions was studied in situ by employing simultaneous, time-resolved X-ray diffraction (XRD) and X-ray absorption spectroscopy (EXAFS) at the Zn K-edge. The precursor solutions were heated from room temperature to the desired reaction temperatures in a hermetically sealed cell dedicated to X-ray experiments. In general, the first indications for the formation of hexagonal ZnO were found for elevated temperatures of about 80 °C both by XRD and EXAFS, and the contributions increase with temperature and time. However, no reaction intermediates could be proved in addition to the Zn precursors and the formed hexagonal ZnO materials. Furthermore, the results show that the efficiency of the reaction, i.e., the conversion of the precursor material to the ZnO product, strongly depends on the solvent used and the reaction temperature. ZnO formation is accelerated by an increased temperature of 165 °C and the use of 1-octanol, with a conversion to ZnO of more than 80% after only a ca. 35 min reaction time according to a detailed analysis of the EXAFS data. For comparison, an identical concentration of Zn acetylacetonate in water or dilute alkaline NaOH solutions and a reaction temperature of around 90 °C leads to a smaller conversion of approximately 50% only, even after several hours of reaction. The particle size determined from XRD for different orientations shows a preferred orientation along the c-direction of the hexagonal crystal system, as well in accordance with scanning electron microscopy. The LaMer model explained this highly non-uniform growth of needle-like ZnO crystallites.

PH Controlled Nanostructure and Optical Properties of ZnO and Al-Doped ZnO Nanorod Arrays Grown by Microwave-Assisted Hydrothermal Method.

The low-temperature microwave-assisted hydrothermal method was used to successfully grow pure and Al-doped ZnO (AZO) nanorod (NR) arrays on glass substrates. The combined effects of doping and pH on the structural properties, surface chemistry, and optical properties of all samples were investigated. Thermodynamic-based simulations of the growth solution were performed and a growth mechanism, that considers the effects of both the pH and Al-doping, is proposed, and discussed. Tuning the solution pH is key parameter to grow well-aligned, single crystal, highly packed, and high aspect ratio nanorod arrays. Moreover, the optical absorption in the visible range is enhanced by controlling the pH value. The PL spectra reveal a shift of the main radiative emission from the band-to-band into a transition involving deep defect levels of Zinc interstitial Zni. This shift is caused by an enhancement of the non-radiative components (phonon relaxation) at high pH values. The production of well-ordered ZnO and AZO nanorod arrays with visible-active absorption/emission centers would increase their potential use in various applications.

Characteristics and resource availability of Zinc-rich fly ash generated from medical waste through rotary and plasma thermal treatment

Fly ash from medical waste (MW) thermochemical treatment is disposed of in concrete landfills due to its well-known pollution property, while its recycling potential is ignored. This study is the first to explore the environmental characteristics, resource availability, and recovery method of medical waste incineration fly ash (MW-IFA) and medical waste plasma vitrification fly ash (MW-PFA) in China. Features of high chloride levels (28.27–42.89%) and richness in Zn (3.15–7.53%) were observed in all fly ash samples. Notably, low-calcium MW-IFA and MW-PFA may posed higher environmental risks due to much higher zinc leaching concentrations (1621.83–5163.97 mg/L) than high-calcium MW-IFA (2.58–5.02 mg/L). Moreover, the resource availability of Zn measured by water washing, acid leaching and thermal treatment was similar, with the range of 20.69–96.84%, 60.89–90.57%, 60.17–96.82%. Hence, considering avoiding excessive energy consumption, the MW fly ash dissolution and recovery (MWFADR) technology, combining water washing and acid leaching processes, was proposed for ZnO and crystal salt production. The results of this work highlight the recovery potential of Zn and Cl in MW fly ash and propose an environmentally and economically sound solution.

Understanding the role of ZnO as activator in SBR vulcanizates: Performance evaluation with active, nano, and functionalized ZnO

AbstractThis study investigates (ZnO)s with different surface features as vulcanization activators in unfilled SBR vulcanizates. ZnO is termed the best activator due to its fast reaction kinetics. A high release of ZnO into the environment harms marine ecosystems, and most ZnO production goes to the rubber sector; therefore, reducing ZnO amount is essential. Active, nano and functionalized ZnO compared to conventional ZnO in SBR matrix; concentration optimized based on curing, mechanical, physical, and dispersion analyses. The Arrhenius equation approximated the cure curve's kinetic constant and activation energy. Crosslink density measured by swelling experiment and solvent freezing point depression. Nano ZnO was used from 0.5 to 2phr, active ZnO from 1 to 4phr, and functionalized ZnO from 1 to 3phr compared to 5phr of conventional ZnO. The tensile strength of N1.5, F1.5, and A2 SBR increased by 5%, 26%, and 18% compared to C5SBR, whose elongation at break improved by 30%, 7%, and 23%. The data were analyzed using tukey HSD post hoc test. Regarding mechanical properties and curing characteristics, 2phr active, functionalized, and 1.5phr nano ZnO is analogous to 5phr conventional ZnO in an unfilled SBR matrix. The quantity of ZnO in rubber vulcanizates decreased successively by 60%, 60%, and 70%.

Facile preparation of porous ZnO microflowers with large surface area

ZnO microflowers (MFs) assembled by many porous nanosheets were prepared through an initial hydrothermal reaction with an extra annealing treatment at 300 °C. The samples were characterized by XRD, SEM, and TEM techniques, as well as the N2 adsorption–desorption test. The results indicated that the ZnO MFs possessed a size of about 6 µm and exhibited a large surface area of 58.6 m2/g, an average pore size of 14.1 nm with size distribution at 15.1 nm. The hydrothermal temperature was found to play an important role in determining the shape and size of ZnO products. Such ZnO MFs with porous structure and huge surface area may have application potential in the fields of gas sensors, photo-catalysis, electrochemical energy storage, and so on. The present synthetic method is simple and cost-effective, and can be extended to the preparation of other metal oxides with controlled structures.

Design of Improved Acetone Gas Sensors Based on ZnO Doped rGO Nanosheets

To meet future social and environmental objectives for diagnosis of human diseases has offered to develop the proficient gas sensors devices with higher selectivity and sensitivity. For the production of ZnO doped reduced graphene oxide (ZnO doped rGO) nanocomposite, a one-pot hydrothermal approach. The morphological, structural and composition of nanocomposite were investigated to confirm ZnO nanoparticle effectively doped on rGO nanosheets. The nanocomposite has exhibited a superior acetone sensing characteristics. Furthermore, the nanocomposite has a high selectivity for acetone vapour. These findings emphasise advantageous synergistic effects among ZnO and excellent rGO sheet substrate properties.