Zinc Oxide Nanoflowers Research Articles

Toxicological evaluation of therapeutically active zinc oxide nanoflowers in pre-clinical mouse model

Our earlier reports established that zinc oxide nanoflowers (ZONF) show significant pro-angiogenic properties, where reactive oxygen species, nitric oxide and MAPK-AKT-eNOS cell signaling axis play an essential task. Considering the significance of angiogenesis in healthcare, our research group has recently demonstrated the in vivo therapeutic application of ZONF (10 mg/kg b.w.) for treating peripheral artery disease. Moreover, based on the angio-neural crosstalk between vascular and neuronal systems, we have further demonstrated the neuritogenic and neuroprotective characteristics of pro-angiogenic nanoflowers (10 mg/kg b.w.) for the treatment of cerebral ischemia. However, it is crucial for a therapeutic material to be non-toxic for its practical clinical applications and therefore assessment of its in vivo toxicity and adverse effect is highly important. Herein, for the first time, we investigate a detailed nanotoxicology of therapeutically active ZONF in Swiss albino mice to evaluate their safety profile and comprehend their aspects for future clinical applications. The maximum tolerated dose (MTD) of ZONF was found to be 512.5 mg/kg b.w. which was employed for acute exposure (2 weeks), showing slight toxicity. However, sub-chronic (4 weeks) and long term chronic (8–12 weeks) studies of nanoflowers exhibited their non-toxic nature particularly at lower therapeutic doses (1–10 mg/kg b.w.). Additionally, in depth genotoxicity study revealed that lower therapeutic dose of ZONF (10 mg/kg b.w.) did not exhibit significant toxicity even in genetic level. Overall, the present nanotoxicology of ZONF suggests their high biocompatible nature at therapeutic dose, offering the basis of their future clinical applications in ischemic and other vascular diseases.

3D ZnO/Activated Carbon Alginate Beads for the Removal of Antibiotic-Resistant Bacteria and Antibiotic Resistance Genes.

The worldwide prevalence of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have become one of the most urgent issues for public health. Thus, it is critical to explore more sustainable methods with less toxicity for the long-term removal of both ARB and ARGs. In this study, we fabricated a novel material by encapsulating zinc oxide (ZnO) nanoflowers and activated carbon (AC) in an alginate biopolymer. When the dosage of ZnO was 1.0 g (≈2 g/L), the composite beads exhibited higher removal efficiency and a slight release of Zn2+ in water treatment. Fixed bed column experiments demonstrated that ZnO/AC alginate beads had excellent removal capacities. When the flow rate was 1 mL/min, and the initial concentration was 107 CFU/mL, the removal efficiency of ARB was 5.69-log, and the absolute abundance of ARGs was decreased by 2.44-2.74-log. Moreover, the mechanism demonstrated that ZnO significantly caused cell lysis, cytoplasmic leakage, and the increase of reactive oxygen species induced subsequent oxidative stress state. These findings suggested that ZnO/AC alginate beads can be a promising material for removing ARB and ARGs from wastewater with eco-friendly and sustainable properties.

Characterization of laser dye concentrations in ZnO nanostructures for optimization of random laser emission performance

Many nanoforms of zinc oxide (ZnO) structures can be synthesized, such as spheres, rods, flowers, disks and walls, as scatter centers in random laser. However, nanoflower and nanowire shapes in this work have received particular interest due to their wide range of applications, including biological, medical cancer cell detection, gas sensors, and biosensors. In this paper, we investigate the optical and morphological properties of two-shaped nanoparticles as scatter centers in the laser active medium on the performance emission of a random laser. Fluorescence and absorption spectra show that 10[Formula: see text][Formula: see text]M for R6G dye and [Formula: see text][Formula: see text]cm[Formula: see text] ZnO NPs are the optimal nanocomposite film concentrations for R6G dye. With excitation energies ranging from 3.44[Formula: see text]mJ to 28.34[Formula: see text]mJ and a repetition rate of 2[Formula: see text]Hz, second-harmonic generation Nd: YAG laser Amplified spontaneous emission (ASE) spectra of the nanocomposite films were observed. The results indicated a minimum bandwidth (Full width at half maximum (FWHM)) of 13[Formula: see text]nm at a threshold energy of 8.65[Formula: see text]mJ for ZnO NW (nanowire) nanocomposite films at [Formula: see text][Formula: see text]cm[Formula: see text] with R6G dye at 10[Formula: see text][Formula: see text]M and Poly(methyl methacrylate) (PMMA). The ZnO NF (nanoflower) nanocomposite film had an FWHM of 11[Formula: see text]nm and a threshold energy of 4.8[Formula: see text]mJ at the same concentrations of R6G dye on PMMA.

A Wearable Self‐Powered Multi‐Parameter Respiration Sensor

AbstractRespiratory disease can be early warned by many respiratory parameters such as intensity, rhythm, temperature, and breath molecules like acetone. It requires a complex process to measure these respiratory parameters simultaneously in clinical practice. Therefore, it is a hot topic to design portable devices especially wearable electronics to monitor respiratory conditions continually in daily life. Here, a flexible self‐powered multi‐parameter respiration sensor based on poly(vinylidene fluoride) (PVDF) thin film and flexible interdigital electrodes that is bonding with sodium‐doped zinc oxide nanoflowers is demonstrated , which can detect airflow, temperature, and acetone during breathing. The respiration sensor may provide some reference ways for the fabrication of miniaturized respiratory disease monitoring devices.

Development and DoE-ANN based optimization of novel swellable matrix-diffusible doxorubicin loaded zinc oxide nanoflowers using sonochemical-precipitation method

This research aimed to acquire doxorubicin loaded zinc oxide nanoflowers (DOX-ZnO-NFs) for intracellular drug cargo possessing a synergistic in-vitro anticancer activity with minimal toxicity. Zinc is the main inorganic metallic component of various enzyme systems and has the possibility of fabrication into the diverse nano-structural forms. An easy absorption and extensive tissue distribution of zinc have made it unique candidate for drug delivery system. Hence, the zinc oxide nanoflowers were prepared with sonochemical-precipitation. The developed system was characterized using the reported methods and was optimized employing design of experiment, coupled with artificial neural network approach. The optimized nanoflowers (DOX-ZnO-NFV) were anionic with particle size of 24 ± 0.05 nm, polydispersity index of <0.5, a zeta potential of −25.68 ± 0.16 mV, yield of 87.40% and encapsulation efficiency of 85.25%. DOX-ZNO-NFV depicted sustained DOX release, around 65.413% release in 30 h at pH 7.4 and assumed Weibull model with its derived parameters, a and b of 22.77 and 0.918, respectively. DOX-ZnO-NFV remained stable on storage for 3 months at 4° C/50% RH and 25° C/60% RH. DOX-ZnO-NFV displayed a zone of inhibition of 13.50 ± 1.25 mm and 25.50 ± 0.98 mm, respectively against gram-positive Staphylococcus aureus and gram-negative Escherichia coli strains, presenting the nanoflowers as self-preservative. DOX-ZnO-NFV exhibited higher in-vitro anticancer activity in Henrietta Lacks cell line, with least hemolysis compared to the free DOX and ZnO-NF. Thus, doxorubicin loaded zinc oxide nanoflowers envisioned to act as better chemotherapeutic cargos with the maximize anticancer activity and minimal toxicity.

Synthesis and gas-sensing properties of ZnO nanoflowers for hydrogen sulphide (H2S) detection

Herein, we report the synthesis, characterization, and gas sensing properties of zinc oxide (ZnO) nanoflowers grown by facile simple solution process. The synthesized ZnO nanoflowers were examined by various techniques to explore their structural, morphological, optical, compositional and gas sensing properties. The details morphological and structural characterizations revealed that the synthesized material possessed flower-shaped morphologies in the nanoscale range with a wurtzite hexagonal crystal structure of ZnO. The high-intense peaks of the synthesized ZnO nanoflowers confirmed high crystallinity. Furthermore, the synthesized ZnO nanoflowers were used as an electrode material to fabricate a facile and low-cost gas sensor to detect hydrogen sulphide (H2S). At an ideal working temperature of 150 °C, the ZnO nanoflowers electrode-based gas sensor displayed remarkable selectivity, good response (48 s), and recovery (97 s) time. Moreover, the fabricated gas sensor exhibited a maximum gas response of 139 (Rg/Ra) towards 50 ppm hydrogen sulphide gas at 150 °C. The unique performance of the ZnO nanoflowers-based gas sensor was attributed to the large surface area of the ZnO nanoflowers, which enabled the fabricated sensor to be a contender for the detection of H2S gas among the wide variety of reported sensors.

Green, Water-Based Synthesis of ZnO Nanostructures

We report on the synthesis of zinc oxide (ZnO) nanostructures using a simple, green, waterbased process, without the aid of any chemical precursor or external energy source. Zinc plates were immersed in deionized water and kept at ambient conditions in a dark cabinet for up to 21 days. After immersion, the reaction products were analyzed using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, photoluminescence spectroscopy and Raman spectroscopy. After short immersion times (1-3 days), ZnO agglomerates with a high concentration of oxygen defects were formed, which overlapped along the c axis to form ZnO nanoflowers. After long immersion times (21 days), ZnO microswords with smooth surfaces, well-defined tips, and less oxygen defects were formed. This low-cost, low-energy synthesis process is an attractive alternative to produce ZnO nanostructures with low impact on the environment.

Nitrogen-doped carbon quantum dots supported zinc oxide (ZnO/N-CQD) nanoflower photocatalyst for methylene blue photodegradation

This research highlights the three-step hydrothermal synthesis of N-CQD and its effect on the physical properties and photocatalytic activity of ZnO/N-CQD compared to ZnO commercial and the prepared ZnO nanoflower. The physical and optical properties of photocatalysts were conducted to investigate the correlation with photodegradation of Methylene Blue (MB) under visible light. During 30 min, MB concentration decreased to 80% by the prepared ZnO/N-CQD. This result showed superior activity compared to ZnO commercial and ZnO nanoflowers. Considering the high photocatalytic performance of ZnO/N-CQD, it can be further used as an efficient photocatalyst for organic pollutant removal from aqueous.

Influence of Structure and Base Modification of Zinc Oxide Nanostructures on Kinetic Parameters of the Transesterification of Rice Bran Oil to Biodiesel

Biodiesel is an alternative to biofuel that could help to reduce the use of fossil fuels and protect the environment. Evaluation of reaction kinetics provides information on reaction rates and mechanism which is necessary in evaluating catalyst’s effectiveness. In this research, zinc oxide (ZnO) nanostructures, nanoparticles, nanoflowers and nanotubes were base-modified with potassium to enhance their active sites and used in the transesterification process for study of kinetic parameters. The nanocatalysts were characterized with FESEM and biodiesel conversion monitored with 1H NMR. The result shows that both structure and base modification have influence on the kinetics parameters. In all the catalysts, activation energy falls within 26-82 kJmol-1indicating that the process was kinetically controlled and nanotubes has the highest rate constant of 0.0287 min-1, lowest activation energy of 59.40 kJmol-1and highest turnover frequency (TOF) of 0.026s-1. The results show that kinetic parameters of transesterification are not only defendant on catalysts’ basic or acid active sites but can also be influenced by structural modification. Therefore, the structural and K-modified ZnO nanoparticles have effect on the kinetic parameters of the tranesterification of rice bran oil (RBO) to biodiel and thus significantly reduce the use of fossil fuels in the environment

One-pot greener synthesis of zinc oxide nanoflowers using potato, cauliflower, and pea peel extract with antibacterial application

The greener synthesis of nanoparticles gives alternatives to conventional methods and holds the advantage of cost and economy with controlled toxicity. In this research work, we have reported the synthesis of zinc oxide (ZnO) nanoflowers (NFs) by using aqueous peels extract of Solanum tuberosum (potato), Brassica oleracea (cauliflower), and Pisum sativum (pea). Magnificent colorful NFs of nearly the same size and morphology were developed from all tested bio-extracts. The average particle size of ZnO NFs tailored from cauliflower, potato and pea were 37.91 nm, 42.37 nm, and 28.6 nm, respectively. The maximum absorption peak for NFs was at 390 nm, and the bandgap calculated through the Kubelka-Munk function for ZnO NFs was between 3.28 and 3.29 eV. ZnO NFs were found thermally stable till 200 °C, and 50% mass loss was between 200 and 400 °C. Antimicrobial efficacy of synthesized NFs was evaluated. They were identified as a robust antibacterial agent, and the inhibitory action at 45 µg/mL was figured out as B. subtilis (25.2 mm) > E. coli (24.1 mm) > S. aureus (21.2 mm) > P. aeruginosa (17.3 mm). The results showed that ZnO NFs could be effectively utilized against Gram-positive and Gram-negative bacteria. Nanoflowers were discovered unrivaled for bactericidal action than precursor material against control. Moreover, comparing this work with published articles about greener synthesis of ZnO NPs displays them as more toxic and versatile.

ZnO-nanoflower thin film photoanodes for photoelectrochemical water splitting: Effect of pH and gallium doping

• Morphology and film formation properties of ZnONF have been manipulated via tailoring the pH. • The optimum pH value to produce a ZnONF-based photoanode is determined as 5.4. • Incident photon-to-current efficiency (IPCE) of ZnONF-based photoanode is 39% at 367 nm. • IPCE of ZnONF thin-film electrodes has been improved to 51% at 367 nm by gallium doping. Utilizing sunlight for energy conversion and storage through photoelectrochemical (PEC) water splitting has been regarded as one of the most featured ways in renewable energy applications. Herein, zinc oxide nanoflower (ZnONF) thin-film photoelectrodes have been prepared using different pH of the reaction solution. Additionally, gallium doping has been applied on the ZnONF thin-film having the highest performance to enhance the PEC efficiency. Consequently, ∼0.8 mA.cm −2 of photocurrent density generated on ZnONF photoanode has been enhanced to ∼1.3 mA.cm −2 (at 0.4 V vs. Ag/AgCl), while maximum IPCE% reached to 51% at 367 nm via gallium doping.

Fabrication of Electrochemical Biosensor Using Zinc Oxide Nanoflowers for the Detection of Uric Acid

A label-free electrochemical biosensor has been developed using zinc oxide nanoflowers (ZnONFs) for the detection of uric acid concentration in human blood serum. ZnONFs have been synthesized by a hydrothermal process and characterized with several techniques such as ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR) studies, X-ray diffraction (XRD) study, Raman spectroscopy, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) and electrochemical analyzer to confirm the formation of nanoflowers and fabrication of electrode and bio-electrodes for uric acid detection. Zinc Oxide nanoflowers have been deposited onto indium–tin oxide (ITO) substrate through electrophoretic deposition technique, and the biosensor has been fabricated by immobilizing urate oxidase (UOx) enzyme onto ZnONFs/ITO electrode surfaces. Further, electrochemical studies have been performed with immobilized UOx/ZnONFs/ITO bio-electrode as a function of uric acid concentrations. It has been found that the fabricated uric acid biosensor shows a high sensitivity (10.38 μA/mM/cm2) and a limit of detection of 0.13 mM in the range of 0.005 to 1.0 mM. This study demonstrates the potential use of ZnONFs for the construction of sensitive biosensors for uric acid detection.

Hexagonal boron nitride nanosheets incorporated photocatalytic polyvinylidene fluoride mixed matrix membranes for textile wastewater treatment via vacuum-assisted distillation

Textile wastewater poses a significant environmental threat, and its treatment is one of the most demanding and challenging problems. This study investigates the feasibility of vacuum membrane distillation (VMD) for colour removal from real textile industry wastewater. Hexagonal boron nitride (h-BN) nanosheets and Zinc oxide (ZnO) nanoflowers were synthesised using a facile single-step synthesis protocol. 1% w/v ZnO nanoflowers and a varied amount of h-BN nanosheets (0–2% w/v) were impregnated in a polyvinylidene fluoride (PVDF) matrix using the phase inversion technique. The h-BN nanosheets, ZnO nanoflowers and membranes were characterised using scanning electron microscopy (SEM), Fourier transform attenuated total reflectance (FT-ATR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The XRD and FT-ATR spectra of the mixed matrix membranes confirmed the successful impregnation of h-BN nanosheets and ZnO nanoflowers in the PVDF matrix. The effect of various process parameters (feed temperature, feed flow rate, and degree of vacuum) on membranes' permeate flux and colour removal efficiency was studied. The M-BZ2 mixed matrix membrane having 18% PVDF+ 2% h-BN nanosheets+ 1% ZnO nanoflowers composition showed the highest flux of 12.98 kg m−2 h−1 and colour removal efficiency of > 98%. Incorporating ZnO nanoflowers in the membrane, matrix provided the membrane with a UV cleaning property. More than 95% of the initial flux was recovered after the UV treatment of the membrane surface. The SEM images confirmed successful photocatalytic degradation of dye and organic molecules from the membrane surface. The UV-treated membranes retained all characteristic bands with no significant alterations. This study established that the M-BZ2 is suitable for treating real textile wastewater with high flux and colour removal efficiency.

Altering the Photoluminescence Emission Quenching and Energy Transfer for the Photocatalytic Behaviour of ZnO Nanostructures

Synthesis of nanoparticles (NPs) is gaining attention as a cost-effective and environmentally acceptable alternative to remove the pollutant by facile photocatalysis process. Role of hydrothermal treatment on Zinc-oxide (ZnO) nanostructures were investigated using non-ionic surfactant diethanolamine (DEA). Further, in order to investigate the effect of DEA on morphological variation different concentration of DEA was used. The samples were thoroughly characterized by XRD, Rietveld analysis, FESEM and TEM to get insight idea about the ZnO structural and morphological properties. Moreover, XPS spectra reveal the variation of surface oxygen defects as hydrothermal treatment induced more defects to ZnO material. BET measurement reveals the alteration of surface area and pore size of ZnO sample. The surface defect-states (mostly oxygen vacancies) of the catalyst nanoparticles can influence the photocatalytic degradation of MB dye activated by ZnO nanoflowers via a non-radiative energy transfer pathway. A steady-state photoluminescence analysis validated the photoinduced electron transport from ZnO to MB dye. Steady state photoluminesence emission spectra established one to one correlation between the defects and colour emission from ZnO. Spectral overlap between donor (ZnO) to acceptor (MB dye) also enhanced greatly after hydrothermal treatment ascribing more Förster resonance energy transfer (FRET) which accelerates photocatalytic degradation efficiency of methylene blue (MB) dye under UV light irradiation. The defect-engineered ZnO nanoparticles synthesized through facile hydrothermal treatment led to an efficient decolourization of MB dye which was strengthened by FRET based on a correlation of photocatalytic degradation and defect mediated colour emission.

Optoelectronic Enhancement of Perovskite Solar Cells through the Incorporation of Plasmonic Particles.

The optoelectronic advantages of anchoring plasmonic silver and copper particles and non-plasmonic titanium particles onto zinc oxide (ZnO) nanoflower (NF) scaffolds for the fabrication of perovskite solar cells (PSCs) are addressed in this article. The metallic particles were sputter-deposited as a function of sputtering time to vary their size on solution-grown ZnO NFs on which methylammonium lead iodide perovskite was crystallized in a controlled environment. Optical absorption measurements showed impressive improvements in the light-harvesting efficiency (LHE) of the devices using silver nanoparticles and some concentrations of copper, whereas the LHE was relatively lower in devices used titanium than in a control device without any metallic particles. Fully functional PSCs were fabricated using the plasmonic and non-plasmonic metallic film-decorated ZnO NFs. Several fold enhancements in photoconversion efficiency were achieved in the silver-containing devices compared with the control device, which was accompanied by an increase in the photocurrent density, photovoltage, and fill factor. To understand the plasmonic effects in the photoanode, the LHE, photo-current density, photovoltage, photoluminescence, incident photon-to-current conversion efficiency, and electrochemical impedance properties were thoroughly investigated. This research showcases the efficacy of the addition of plasmonic particles onto photo anodes, which leads to improved light scattering, better charge separation, and reduced electron–hole recombination rate.

Synthesis of two different zinc oxide nanoflowers and comparison of antioxidant and photocatalytic activity

Nanoflowers are a newly developed class of nanoparticles that show flower-like structures and attract much attention due to their simple preparation methods, high stability, and increased efficiency. The aim of the study is to investigate a strong alternative to reduce the severity of infection and increase the treatment of wastewater by exhibiting biofilm inhibition in medical and environmental applications of the ZnO-NFs with two different shapes. ZnO-NFs were synthesized by two different processes hydrothermal method (named ZnO–NF1) and the precipitation method (named ZnO–NF2). ZnO-NFs produced by two different synthesis methods were compared for the photocatalytic and antioxidant efficiency. The effects of Reactive Red 180 (RR180) and Basic Red 18 (BR18) dyes concentration, photocatalyst amount, and reaction time were investigated on dye removal efficiency for photocatalytic experiments. The color was completely removed for 25 mg/L BR18 and RR180 dyes for 75 min and 90 min, respectively, using 1.5 g/L photocatalyst amount using ZnO–NF1. However, 59.18% dye removal efficiency was obtained for 90 min by using a 1.5 g/L ZnO–NF2 photocatalyst for 25 mg/L BR18 dye removal, while a dye removal efficiency of 90.00% was detected for 90 min using 2 g/L ZnO–NF2 for 25 mg/L RR180 dye. Then, comparison of general properties such as antibacterial, antibiofilm, microbial cell viability, DNA fragmentation, antioxidant activities, and antimicrobial photodynamic therapy of ZnO-NFs were investigated. The antioxidant activity of ZnO–NF2 was found to be higher than ZnO–NF1 at each concentration (82.32% and 87.18% for ZnO–NF1 and ZnO–NF2, respectively, at 200 mg/mL).

Optical Properties of Hydrothermally Grown ZnO Nanoflowers

Abstract: A simple hydrothermal method has been successfully employed to synthesize flower-like ZnO nanostructure. X-ray diffraction data confirm the formation of ZnO with a Wurtzite structure. FESEM images show the flower-like morphology of the synthesized nanostructures. The energy dispersive X-ray spectroscopic analysis confirms the stoichiometric composition.. X-ray fluorescence spectrum shows no impurity element in the synthesized ZnO. The synthesized ZnO exhibits low absorption in the visible region of wavelength. Band gap enhancement was also observed owing to the quantum confinement effect. The synthesized ZnO nanoflowers exhibit strong room-temperature photoluminescence with a broad emission peak at 429 nm arising due to the recombination of electrons at zinc interstitials and holes in the valence band. This defect-related photoluminescence is very important in the context of understanding the defect dynamics in ZnO. Background: Zinc oxide (ZnO) is a well-known multifunctional material possessing unique structural, electrical, and optical properties that are very useful in various device applications. Being a high and direct band gap semiconductor, it is potentially being used in various UV light sources and detectors fabrication. However, the emission and absorption properties strongly depend on the size of the ZnO nanoparticles which in turn depends on the morphology of the nanostructure. Therefore, it is very much important to understand the structure-property relationship for a predictable device performance. Objectives: Our objective of this work is to synthesize flower-like ZnO nanostructures using a simple hydrothermal method. The flower-like ZnO morphology offers a large surface area that will be very suitable for designing gas and chemical sensor devices. Another objective of this work is to study the crystallography of ZnO. Next, the optical properties (emission and absorption) have been investigated to understand the defect-related photoluminescence mechanism. Method: A simple hydrothermal method has been deployed to synthesize flower-like ZnO nanostructures. A chloride decomposition scheme has been used to produce zinc hydroxide ions that will produce ZnO nuclide. At the onset of saturation, ZnO nanocrystals start to grow. The entire reaction was performed inside a Teflon cell stainless steel autoclave. The autoclave was placed in a horizontal tube furnace and maintained at 150 °C for 2 hr. resulting in the formation of white powder-like material. Results: The X-ray diffraction data confirm the formation of polycrystalline ZnO having a Wurtzite structure. Flower-like morphology was clearly observed in FESEM images. The EDS data confirm the composition of ZnO with proper stoichiometry. Gibb’s free energy calculation favors the reaction under the experimental condition. The absorption spectrum was used to calculate the band gap of the synthesized ZnO nanoflowers. The Tauc plot revealed the band gap of the synthesized ZnO to be~ 3.69 eV. This enhancement of band gap compared to bulk ZnO occurs due to the quantum confinement effect. The synthesized ZnO nanoflowers exhibit broad photoluminescence peaked at 429 nm owing to the presence of interstitial zinc. Conclusion: A hydrothermal method has been successfully used to synthesize well-crystalline ZnO nanoflowers of proper stoichiometry. The flower-like nanostructure exhibits band gap enhancement due to the quantum confinement effect. Room temperature visible photoluminescence was observed from the ZnO nanoflowers with a board emission peak at 429 nm. This emission arises due to the presence of deep-level zinc interstitial states. This finding will be very useful in understanding the role of defects in the visible emission from ZnO nanostructures.

Facile synthesis of Sm doped ZnO nanoflowers by Co-precipitation method for enhanced photocatalytic degradation of MB dye under sunlight irradiation

Rare earth (RE) metal doping into the metal oxide semiconductor (MOS) is considered an effective way to boost photocatalytic performance for its capability to decelerate the electron-hole pair recombination upon excitation. In the current work, Zinc oxide (ZnO) nanoflowers were synthesized via facile co-precipitation method with varying concentrations of samarium (Sm) ions. Several techniques were used to analyze the structural, morphological, optical, and elemental composition properties of the prepared photocatalyst. FE-SEM studies revealed the nanoflower-like morphology, whereas the structural properties confirm the wurtzite crystal structure of ZnO which is identified by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) analysis. Additionally, the observed shift in XRD planes toward lower theta values justifies the incorporation of Sm3+ ions into the Zinc Oxide lattice. The photo induced activity of Sm doped ZnO nanoflowers was studied by the degradation of methylene blue (MB) under sunlight irradiation, especially 5% Sm-ZnO shows the highest degradation efficiency with 96% within 90 min. The photocatalytic degradation mechanism and scavenger test towards MB using Sm doped ZnO NFs have also been discussed.

Biogenic ZnO Nanoflowers: As an Alternative Antibacterial Nanomedicine

Background: Zinc oxide (ZnO) nanoparticles have been widely investigated for the development of next-generation nano-antibiotics against a broad range of microorganisms including multi-drug resistance. The morphology of nanomaterials plays an important role in antibacterial activity. Objective: The research goal is focused on the development of a low-cost antibacterial agent. Method: The biosynthesis method was used to make ZnO nanoflowers. The antibacterial activity of these biogenic ZnO nanoflowers was analyzed by three methods: growth curve, well diffusion, and colony-forming unit count (CFU) assays. Results: The assay methods used in this study confirmed the antibacterial activity of ZnO nanoflowers. The growth curve shows that 0.5 mg/mL concentration of ZnO nanoflowers acted as an effective bactericide as no significant optical absorption and virtually bacterial growth were ob-served. The inhibition zone was found at 25 mm at 70 μg of ZnO nanoflowers. Conclusion: The unique, simplistic, environmental-friendly, and cost-effective biosynthesis method was established for the ZnO nanoflowers using biomass of Bacillus licheniformis. The resulted ZnO nanoflowers show excellent antibacterial activity which could be used as an alternative to antibiot-ics in therapeutic processes.

Biofunctionalized zinc oxide nanoflowers coated textiles for UV protection

The amount of UV radiation reaching the earth's surface increases day by day. Nanoparticle-coated textiles are an effective way to protect human skin against this radiation. Here, biofunctionalized zinc oxide nanoparticles synthesized in the presence of casein were applied to the cotton material to study the sunscreen action of the textiles. UV–visible photo spectrometry and ultraviolet protection factor analysis identify the effectiveness of UV protection provided by the prepared material. The coated fabrics are found to have 90% or above UV blocking properties and find potential applications in medical, cosmetic, or sports fabrics.