Fabricated ZnO Nanoparticles Research Articles

Synergistic bifunctionality of ZnO nanowalls: Antibacterial activity and photocatalysis through integrated in silico and in vitro approaches

This research investigation delves into the versatile attributes of ZnO nanowalls, specifically probing into their dual functionality encompassing antibacterial and photocatalytic properties. The synthesis of ZnO was achieved by employing a microwave-mediated co-precipitation technique. The resulting sample underwent thorough characterization through diverse analytical methodologies. X-ray diffraction analysis disclosed the prevalence of the hexagonal wurtzite phase, as confirmed by JCPDS card No. 36–1451, with an average crystallite size determined as 23.48 nm. Tauc plot extrapolation method was applied to the UV absorption spectrum to ascertain the bandgap energy. The ZnO nanostructure morphology, featuring multi-directional nano-walls, was unveiled through scanning electron microscopy (SEM). The BET nitrogen adsorption technique quantified the surface area of the ZnO sample as 6.69 m2/g. In antibacterial evaluation, the in vitro (disk diffusion) method showcased the remarkable efficacy of ZnO against both gram-positive Staphylococcus sp. and gram-negative E. coli bacteria. Complementing these experimental findings, in silico molecular docking studies exposed both nano ZnO ligands with standard and corrected lattice parameter values exhibiting favorable binding energy. Moreover, the synthesized ZnO nanoparticles exhibited remarkable photocatalytic activity, particularly demonstrated in the decolorisation of Azure A and Azure B dyes, following the first-order Langmuir–Hinshelwood kinetic model. The collective findings underscored a synergistic effect within the fabricated ZnO nanoparticles, showcasing their dual prowess in both antibacterial and photocatalytic activities. The observed phenomenon can be chiefly ascribed to the presence of lattice strain and dislocation density. This intriguing dual functionality positions them as promising candidates for potential applications in wastewater treatment.

Green method for preparation ZnO nanoparticles using red peony leaves extracts

The source of clean, dry red peony leaves has been carefully packaged and preserved. Then the red peony leaves were extracted to get the extracts solution at the optimum extraction temperature, extraction time and leaves sample weight. The precursor material used to prepare ZnO nanoparticles with spherical wurtzite structure was zinc acetate dihydrate salt (Zn(O2CCH3)2.2H2O) with the reducing and stabilized agent being flavonoid extraction from red peony leaves. The structure and characterizations of the fabricated ZnO nanoparticles were studied by measurement methods such as XRD, SEM, EDX, reflectance spectra. The study results showed that the extraction parameters of peony leaves to obtain the optimal flavonoid extraction yield were red peony leaves weight of 20 grams extracted in 100 ml of distilled water, extraction time of 60 minutes and extraction temperature of 70 °C. ZnO spherical wurtzite nanoparticles were prepared by wet chemical method at low temperature of 110 oC, with particle size according to SEM were about of 200-400 nm. The band gap was determined by the Kubelka-Munk method to achieve Eg» 3.05-3.17 eV. The ZnO spherical wurtzite nanoparticles were prepared in this our study with further purposes will be modified to reduce the Eg bandgap energy for applications as highly effective absorbents, photocatalysts in the visible light region.

Bacillus sp. extract used to fabricate ZnO nanoparticles for their antagonist effect against phytopathogens.

In order to achieve the food demand of a growing population, agricultural productivity needs to be increased by employing safe strategies. In the present study we have evaluated ZnONPs that were synthesized from the culture supernatant of Bacillus subtilis. Bio mimetically synthesized ZnONPs showed a surface resonance peak of 355nm corresponding to NPs formation. Further, NPs were examined for their size, shape and element confirmation by DLS, AFM, SEM, TEM and EDAX, which confirmed the synthesized NPs were nearly spherical in size with average diameter of 32nm by TEM. Surface charge of + 34.3 mV was observed for NPs with a low poly-dispersity index of 0.21. In vitro efficacy studies against fungi Colletotrichum capsici, Sclerotium rolfsii, Alternaria solani and Fusarium oxysporumf. sp. cicero showed up to 99% mycelial growth inhibition at 0.125% ZnONPs. Further, in-vitro disk-diffusion assay showed inhibition zones of 23 ± 0.4mm and 12.67 ± 0.24mm forXanthomonasaxonopodis pv. punicae (Xap) and Xanthomonas oryzae pv. oryzae (Xoo) bacterial cultures. Plant toxicity study was observed that ≤ 0.14% NPs concentration was safe under greenhouse conditions. Overall, the present study emphasizes the potential effect of ZnONPs against agricultural pathogens which play an important role in agriculture production.

ZnO nanoparticles and their properties as surface coating materials against coronavirus: viewpoint

A pandemic of coronavirus infection is causing a significant public health hazard globally, putting millions of people at risk in an increasing amount of countries. Nanostructured materials have been recognized to be highly efficient against coronaviruses. ZnO nanoparticles possess unique features that enable to act as anti-bacterial and anti-viral. Hence, the aim of the current investigation is to produce zinc oxide nanoparticles and utilized as surface coating materials against COVID-19. Thermal decomposition has been utilized in this investigation to fabricate ZnO nanoparticles with crystallite of 41 and 55 nm. The study outcomes demonstrated that Zinc nanoparticles is a favorable material for future usage as an anti-coronavirus surface due to their ecologically friendly features and exceptional physical and chemical functionality.

Livistona jekinsiana fabricated ZnO nanoparticles and their detrimental effect towards anthropogenic organic pollutants and human pathogenic bacteria

An environment-friendly and economically sound method was developed to achieve a multi-functional ZnO nanoparticles (ZnO NPs) using water extract of Livistona jekinsiana. The ZnO NPs absorbed maximum wavelength of light at 332 nm in UV–Visible spectroscopy (UV/Vis). X-Ray Diffraction (XRD) pattern revealed the crystallinity of the nanoparticles with the crystallite size around 22.45 nm. The geometry, shape, size, and elemental composition were determined by Transmission Electron Microscope (TEM) and Energy Dispersive Spectroscopy (EDS). The presence of phytochemicals and the typical zinc-oxygen group in the ZnO NPs was implied by Fourier Transform Infrared spectroscopy (FTIR). Photo luminescence spectroscopy (PL), and Dynamic Light Scattering (DLS) techniques were also used to characterize and study the different features of ZnO NPs. The multifunctional ZnO NPs showed an efficient photodegradative effect towards the degradation of two anthropogenic dyes, methyl orange (MO) and methylene blue (MB) under solar radiation. The degradation reaction of MO and MB was compliantwithzero-order kinetics and first-order kinetics respectively. Also, Livistona jekinsiana fabricated ZnO NPs showed potential Antibacterial activity against S. aureus, B. subtilis, E. coli and K. pneumonia bacteria and effective antioxidant activity using DPPH scavenging assay. The mechanism of the antibacterial activity was established by estimating the ROS generation and percentage of DNA in K. pneumonia cell. The study illustrated the reducing and stabilizing property of the Livistona jekinsiana extract as a novel source and potential photodegradative and therapeutic effects of the ZnO NPs.

Synthesis and characterization of phytochemical fabricated zinc oxide nanoparticles with enhanced antibacterial and catalytic applications

A “green route” to fabricate nanoparticles has emerged as a revolutionary approach. The reported work presents a green approach to synthesize ZnO nanoparticles using Conyza canadensis plant leaves extract. The synthesis of ZnO was conducted at two different temperatures i.e. 30 °C and 80 °C. ZnO nanoparticles prepared at 80 °C were smaller in size and exhibited spherical morphology. The prepared nanomaterials were examined for the reduction of organic dyes i.e. methylene blue and methyl orange. The fabricated ZnO nanoparticles synthesized at 80 °C were found to be highly active for the reduction of aforementioned dyes with 94.5% reduction of MO and 85.3% reduction of MB in 45 min and 20 min respectively. The rate constant (k) for this reduction of MO was found to be 5.781 × 10−3 s−1 in the absence of a catalyst and 5.843 × 10−2 s−1 in the presence of ZnO NPs catalyst. The rate constant (k) for the reduction of MB was found to be 4.7 × 10−3 s−1 in the absence of a catalyst and 9.936 × 10−3 s−1 in the presence of ZnO NPs catalyst. ZnO nanoparticles synthesized at 80 °C were examined for their antibacterial activity. The biogenic ZnO nanoparticles exhibited strong antibacterial activity against E. coli and S. aureus with a zone of inhibition (16 mm) and (14 mm) respectively. This high antibacterial and catalytic activity of biogenic ZnO nanoparticles can be attributed to its small size, good dispersion, and well-defined morphology.

ZnO nanoparticles as sensing materials with high gas response for detection of n-butanol gas

The high crystallinity ZnO nanoparticles with an average particle diameter 30 nm have been successfully synthesized with a surfactant-mediated method. The cationic surfactant (cetyltrimethylammonium bromide, CTAB) and the hydrous metal chlorides (ZnCl2⋅2H2O) appear to be the good candidates for obtaining a high yield of nanoparticles. The structural and morphological characterizations were carried out by X-ray powder diffraction, scanning electron microscope and transmission electron microscopy, respectively. The resulting powders are highly crystalline and largely monodisperse ZnO nanoparticles. When used as a sensing material in gas sensor, it exhibits the high-performance gas sensing performances including high gas response, good selectivity, fast response/recovery time, good repeatability as well as stability towards low-ppm-level (10 to 100 ppm) n-butanol gas. At the optimal operating temperature (260 oC), its gas response toward 100 ppm butanol is 174.8. The response and recovery time are 18 and 11 seconds, respectively. Theses findings not only provide a novel approach to fabricate ZnO nanoparticles via a surfactant-mediated method, but also explore a promising gas sensor towards n-butanol.

Green photoluminescence from highly oriented ZnO thin film for photovoltaic application

We report here the fabrication of ZnO nanoparticles embedded on glass substrate by sol–gel and spin coating technique. Transmission electron microscope images revealed that the thin film is composed of ZnO nanoparticles. X-ray diffraction data confirms that the fabricated ZnO nanoparticles have hexagonal unit cell structure. The ZnO nanocrystals of the thin film are oriented along the c-axis of the hexagonal unit cell. UV–vis absorption spectroscopy shows that the absorption occurring at 373nm in the ZnO thin film. The band gap was calculated from the absorption data and found to be 3.76eV. This band gap enhancement occurs due to size effect in the nanoscale regime. Room temperature photoluminescence spectrum shows strong green emission at 530nm owing to the singly ionized oxygen vacancy. This green emission was further investigated by annealing the thin film at different temperature. This singular green emission will be very useful in optoelectronic and nanophotonic devices.

Fabrication of ZnO nanoparticles by solution-combustion method for the photocatalytic degradation of organic dye

ZnO nanoparticles (NPs) were successfully fabricated by simple combustion process, in which Zn(CH3COO)2 precursors migrated with the aid of alcoholic fuel to the top of a burning lampwick and the chemical reactions occurred at the solvent-air interface of the ignited lampwick, yielding ZnO NPs. Ultraviolet-visible spectroscopic analysis and energy-dispersive spectroscopic elemental analysis revealed that the fabricated ZnO NPs are comprised mainly of Zn and O atoms. It was observed that most of the ZnO NPs exhibited an ellipsoidal shape having a particle size of 100 to 200 nm for short-length axes and 100 to 400 nm for long-length axes. To see the effectiveness of the fabricated ZnO NPs, it was employed as photocatalytic agent to degrade the organic dye, viz. Rhodamine B, and catalytic activities under both sunlight and UV light were analyzed and compared with respect to the commercially available ZnO (Fluka). The initial degradation rate in fabricated ZnO NPs was almost double than that of ZnO (Fluka). Furthermore, by exposing to sunlight for 1 h, the fabricated ZnO NPs degraded Rhodamine B dye more than 80%, whereas it was only approximately 35% for ZnO (Fluka). Photocatalytic activities might be attributed to porous structures with larger active surface area of the nanosized ZnO particles. With this advantage, 96% of organic contaminants were degraded by the fabricated ZnO NPs upon exposure to sunlight for 2 h.

Polyol mediated synthesis of ZnO nanoparticles templated by bacterial cellulose

Zinc oxide nanoparticles have been successfully synthesized through a facile polyol method using bacterial cellulose (BC) as a template. BC membrane was used as a host matrix to introduce quantitatively Zn2+ ions and then as nanoreactors to fabricate ZnO nanoparticles by hydrolysis of zinc acetate in a polyol medium. The influence of the concentration of zinc acetate and hydrolytic time on the morphologies and size of ZnO nanoparticles were investigated. The results indicated that the uniform spherical ZnO nanoparticles were incorporated into BC fibers. The resulting nanocomposites show good mechanical properties and high photocatalytic activity in the degradation of methyl orange.

Femtosecond laser ablation of ZnO nanorods for two-photon-pumped random lasing and optical data storage

Femtosecond laser ablation based on two-photon absorption was employed to cut ZnO nanorods into uniform ZnO nanoparticles of deep subwavelength size. The fabricated ZnO nanoparticles possess a shorter mean transport length for photons at the emission wavelength and a much smaller scattering cross section at the pump wavelength, leading to highly efficient two-photon-pumped random lasing with a low threshold of ∼8 mJ/cm2. It was demonstrated that the significant enhancement in two-photon luminescence after the irradiation of femtosecond laser pulses could also be utilized for realizing optical data storage.

Photoconductivity characteristics of ZnO nanoparticles assembled in nanogap electrodes for portable photodetector applications

In the present report, ZnO nanoparticles of size ∼9 nm have been assembled by optimized dielectrophoresis process on the pre-fabricated nanogap (60 nm) electrodes. The fabricated ZnO nanoparticles based nano-device was studied for its I– V characteristic and typical non-linear semiconducting behavior was observed. When illuminated with ultraviolet (UV) radiation of wavelength 365 nm, a tremendous change in conductivity of almost one order of magnitude was observed indicating a high sensitivity of the fabricated nano-device. Temporal photoresponse characteristics were studied at a fixed level of UV illumination intensity (1.0 mW/cm 2) and the response time under 10 ms was recorded. The photoresponse curve exhibited a perfect rise and recovery without any slow component. Absence of slow component in the photoresponse characteristic suggested that shallow trapping centers were inactive and the photoconductivity could be due to the true quantum yield of photogenerated charge carriers through interband and deep trapping centers transitions.

Fabrication and characterization of anodic ZnO nanoparticles

We have successfully fabricated ZnO nanoparticles by anodizing Zn sheet in 0.1 M sodium hydroxide solution. Morphology observations demonstrate that the sizes of the ZnO nanoparticles have a tendency to increase with rising anodic voltage. Detailed structural characterizations illuminate that oxygen vacancies exist in the anodic ZnO nanoparticles with wurtzite structure. Photoluminescence from the ZnO nanoparticles exhibits a very broad visible emission band, which can be Gaussian divided into three subbands around 2.4, 2.8, and 3.0 eV. Spectral examinations and analyses reveal that the three subbands are connected with oxygen vacancies, interstitial zinc sites, and the ZnOx matrix, respectively. Our results improve the understanding of the light-emitting mechanism in ZnO nanomaterials.