Synthesis Of ZnO NPs Research Articles

Mycosynthesis, Characterization of Zinc Oxide Nanoparticles, and Its Assessment in Various Biological Activities

In recent years, nanotechnology has become one of the emerging fields of nanoparticle synthesis using biological processes. The use of mushroom extract is one of the most important methods for biological synthesis due to the presence of abundant biologically active compounds. In this study, Zinc Oxide nanoparticles (ZnO NPs) were synthesized using Daedalea sp. mushroom extract. The nanoparticles had an average size of 14.58 nm and irregular morphology, which shows its prominent character. Various analytical techniques including FTIR, X-ray diffraction, EDX, and UV-Vis spectrum showed a broad absorption between 350 and 380 nm, which indicates the synthesis of ZnO NPs. The characterized NPs were exploited for a wide range of biomedical applications including biocompatibility, antifungal, antileishmanial, and antibacterial studies. The ZnO nanoparticles showed a strong antibacterial effect against gram-positive (Klesbsilla pneumonia and Staphylococcus aureus) and gram-negative (Eschericia coli and Pseudomonas aeruginosa) bacteria. Furthermore, the ZnO nanoparticles also showed a high antifungal effect against Aspergillus niger fungus.

Facile Green Synthesis of ZnO NPs and Plasmonic Ag-Supported ZnO Nanocomposite for Photocatalytic Degradation of Methylene Blue

Removing organic pollutants, textile dyes, and pharmaceutical wastes from the water bodies has become an essential requirement for a safe environment. Therefore, the present study aimed to prepare semiconductor zinc oxide nanoparticles (ZnO NPs) and plasmonic Ag-supported ZnO nanocomposite (ZnO–Ag) using an environmentally friendly bio-approach as an alternative to hazardous synthesis approaches. ZnO NPs and ZnO–Ag nanocomposite were characterized by using UV–Vis diffuse reflectance spectroscopy (UV–DRS) (the Ag-supported ZnO nanocomposite exhibited an absorption band between 450–550 nm, attributed to the Ag NPs surface plasmon resonance (SPR)), Photoluminescence (PL) spectral investigation, which revealed the PL emission intensity of ZnO–Ag NPs was lower than pure ZnO NPs, describing an extended electron-hole pair (e--h+) lifespan of photogenerated charge carriers, Fourier transform infrared spectroscopy (FTIR), FT-Raman, and X-ray diffraction (XRD) analyses were deduced. In addition, energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) were performed and further ascertained the successful biosynthesis and thermally stable ZnO Nps and ZnO–Ag nanocomposite. The as-prepared ZnO–Ag nanocomposite displayed increased photocatalytic characteristics due to the decline in the bandgap energy from 3.02 eV (ZnO NPs) to 2.90 eV (ZnO–Ag nanocomposite). The photocatalytic activity of the developed nanocomposite for the degradation of methylene blue (MB) dye, a primary textile industry released water-pollutant, was conducted under UV light irradiation. Meanwhile, the maximum % degradation of MB dye molecules was attained by 98.0 % after 60 min exposure of UV-light irradiation. Increased photocatalytic activity of ZnO–Ag nanocomposites and a faster rate of MB degradation were achieved by the deposition of plasmonic Ag NPs and the surface plasmon resonance (SPR) effect possessed by Ag NPs. The primary oxidative route that resulted in MB degradation was the production of hydroxyl radicals (OH•). The SPR effect of the photocatalyst induced the synergistic enhancement of the optical response and separation of the photo-induced charge carriers. The combined study gives comprehensive information and directions for future research on noble metal-modified nanocatalysts for direct applications in the photocatalytic degradation of textile and organic wastes in water.

Biosynthesis and Antimicrobial Evaluation of Zinc Oxide Nanoparticles Using Chlorella vulgaris Biomass against Multidrug-Resistant Pathogens.

The rampant increase in antibiotic resistance has created a global barrier to the treatment of multidrug-resistant infections. Biogenic synthesis of nanomaterials is a novel approach to producing nanostructures with biological resources. Algae are known to be clean, nontoxic, cost-beneficial, and environmentally acceptable. Chlorella vulgaris is a popular microalga for its broad applications in food, supplements, pharmaceuticals, and cosmetics. In this study, we used Chlorella vulgaris biomass lyophilized powder as our green resource for the biosynthesis ZnONPs. Chlorella vulgaris culture was harvested at the end of the logarithmic phase, and the biomass was lyophilized. ZnONPs were synthesized using lyophilized biomass and 20 mM zinc acetate dihydrate at a temperature of 70 °C and continuous stirring in a water bath overnight. At the end of the reaction, UV-Vis absorption of colloidal suspension proved the synthesis of ZnONPs. The physicochemical characteristics of nanoparticles were analyzed using FTIR, DLS, TEM, and XRD. Based on FTIR spectra. The antibacterial activity of green synthesized nanostructures was evaluated against methicillin-resistant staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The synthesized ZnONPs have oxygen-containing groups on the surface that show the synthesized nanoparticles' stabilization. The Zeta potential was -27.4 mV, and the mean particle size was measured as 33.4 nanometers. Biogenic ZnONPs produced in this method have a notable size distribution and excellent surface energy, which can have vast applications like antimicrobial potential in pharmaceuticals as topical forms. Additionally, in order to evaluate the antimicrobial activity of ZnO nanoparticles, we used MRSA and VRE strains and the results showed the anti-MRSA activity at 400 and 625 μg mL-1, respectively. Thus, these biogenic ZnO nanoparticles revealed a substantial antibacterial effect against multidrug-resistant pathogens, associated with several serious systemic infections, and have the potential as an antimicrobial agent for further study.

Green Fabrication, Characterization of Zinc Oxide Nanoparticles Using Plant Extract of Momordica charantia and Curcuma zedoaria and Their Antibacterial and Antioxidant Activities.

In recent years, the rapid increase in the resistance of microorganisms to antibiotics has produced major health issues. Novel applications for these compounds have been developed by integrating modern technologies such as nanotechnology and material science with the innate antibacterial activity of metals. The current study demonstrated the synthesis of zinc oxide nanoparticles (ZnO NPs) from Momordica charantia and Curcuma zedoaria plant extracts, as well as their antibacterial properties. The synthesis of ZnO NPs was confirmed via UV-visible spectroscopy, showing clear peaks at 375 and 350nm for M. charantia and C. zedoaria, respectively. Scanning electron microscopy (SEM) analysis revealed crystals of irregular shapes for the majority of the nanoparticles synthesized from both plants. The existence of ZnO NPs was confirmed using X-ray diffraction while the particle size was calculated using Scherrer's equation, which was 19.65 for C. zedoaria and 17.02 for M. charantia. Different functional groups were detected through Fourier transform infrared spectroscopy analysis. The antibacterial activity of the ZnO NPs at three different concentrations (250, 500, and 1000µg/ml) was assessed against three different bacterial strains, i.e., Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa), using disc diffusion methods. The ZnO nanoparticles showed promising antibacterial activity against bacterial strains. For C. zedoaria, the highest growth inhibition was observed at a concentration of 1000µg/ml, which was 18, 19, and 18mm as compared to antibiotics (15, 11, and 15.6mm) against E. coli, P. aeruginosa, and S. aureus, respectively. Similarly, at 1000µg/ml of NPs, M. charantia showed the highest growth inhibition (18, 15, and 17mm) as compared to antibiotics (15, 11, and 14.6mm) against E. coli, P. aeruginosa, and S. aureus, respectively. In conclusion, compared to pure plant extract and antibiotics, ZnO NPs at a higher concentration (1000µg/ml) exhibited a significant difference in zone of inhibition against all the bacterial strains. Different concentrations of ZnO using M. charantia and C. zedoaria caused increments in the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The nanoparticles extracted using C. zedoaria exhibited higher antioxidant activity than M. charantia. Greenly synthesized ZnO nanoparticles have remarkable antibacterial properties and antioxidant activity, making them a promising contender for future pharmaceutical application.

OPTIMIZATION SYNTHESIS OF ZINC OXIDE NANOPARTICLES USING FACTORIAL DESIGN AND ITS ANTIBACTERIAL ACTIVITY

Due to their chemical stability, potent antibacterial activity, and comparatively low hazardous profile, inorganic metal oxides may be used as efficient antibacterial. Zinc oxide nanoparticles (ZnO NPs) significantly slow down the growth of various bacteria. This study aimed to determine the effect and interaction of pH, calcination temperature, and pectin (capping agent) on the synthesis and antibacterial activity of ZnO NPs. The synthesis was carried out by the precipitation method. Synthesis optimization using Design Expert software (factorial design) with parameters including yield, particle size, polydispersity index, zeta potential, particle shape, and inhibition zone of bacteria (P.acnes, S.aureus, and S.epidermidis). This study proves that the synthesis of ZnO NPs is influenced by pH, calcination temperature, and pectin. Various characteristics of the synthesized ZnO NPs have different antibacterial activity. The results of Design Expert analysis with 3 g of precursor obtained the optimum combination at pH 8.8, calcination temperature of 600°C, and pectin 0.76%.

Investigation of the antibacterial efficacy of Zinc Oxide Nanoparticles (ZnO NPs) based Irrigant against Enterococcus faecalis Concerning Root Canal Disinfection

The present study is aimed to investigate the antibacterial efficacy of Zinc Oxide Nanoparticles (ZnO NPs) based irrigants for root canal disinfection. The ZnO NPs-based irrigant was tested in-vitro on Enterococcus faecalis (ATCC: 29212) with NaOCl as a positive control. In this direction, ZnO NPs are very important as they are biocompatible, non-cytotoxic, cheap and easy to produce. The synthesis of ZnO NPs was carried out by facile semi-solvo thermal route using zinc acetate and urea as precursors and a mixture of deionized water and ethylene glycol as solvent. The optical, structural and morphological analyses were carried out by UV-Vis spectroscopy, XRD, SEM and TEM. The qualitative and quantitative antimicrobial activity of ZnO NPs were tested against Enterococcus faecalis containing 1/*105 CFU/ml. The structural and morphological analysis of ZnO NPs reveals the formation of a hexagonal crystal structure having flowerlike morphology where each flower is made up of petals with a thickness of 10-50 nm. The absorption edge was found to be shifted to the lower wavelength at 340 nm which can be due to the size quantization effect. The band gap value was calculated to be 3.65 eV. The inhibition zones were observed in all concentrations with positive control. The MIC and MBC of ZnO NPs were found to be 250 μg/ml and 1000 μg/ml, respectively. Overall, ZnO NPs synthesized by the semi-solvo thermal method were found to be an effective antibacterial agent against E. faecalis. Therefore, ZnO NPs can be used in irrigant solutions for better protection of the oral canal from E. faecalis.

Plant Mediated Green Synthesis of ZnO NPs and Their Potential Regenerative Applications: A Review

Plant Mediated Green Synthesis of ZnO NPs and Their Potential Regenerative Applications: A Review

The effect of reaction and annealing temperatures on physicochemical properties of highly stable ZnO nanoparticles synthesized via a green route using Plumeria obtusa L.

Green synthesis of ZnO NPs and its properties.

Comparative study of zinc oxide nanoparticles synthesized through biogenic and chemical route with reference to antibacterial, antibiofilm and anticancer activities

The present focused on comparative study on synthesis of ZnO nanoparticles (ZnO NPs) using chemical method via alkaline precipitation method (ZnO(A) NPs) using NaOH and biogenic method using termite mound extract (ZnO(B) NPs). GC-MS analysis revealed that D-limonene present in termite mound extract might be responsible for the synthesis of ZnO(B) NPs. XRD patterns confirmed hexagonal crystalline structure of ZnO(A) and (B) NPs. Results of antibacterial activity illustrated that ZnO(B) NPs showed its potential against Pseudomonas aeruginosa, ESBL-1, ESBL-2 and EBSL-3. Antibiofilm studies revealed that ZnO(B) NPs exhibited optimum decline in MRSA biofilm formation than ZnO(A) NPs. In addition, ZnO(B) NPs showed potent cytotoxic effect against lung cancer cell lines A549 with IC50 of 35.16 ± 0.10 μg/mL in comparison with ZnO(A) NPs (IC50- 55.09 ± 0.30 μg/mL). Overall, the results revealed that biogenic synthesis of ZnO NPs ensures its biosafety level and enhanced biological activity when compared to chemical synthesis method.

Antibacterial and Photodegradation of Organic Dyes Using Lamiaceae-Mediated ZnO Nanoparticles: A Review.

The green synthesis of zinc oxide nanoparticles (ZnO NPs) using plant extracts has been receiving tremendous attention as an alternative to conventional physical and chemical methods. The Lamiaceae plant family is one of the largest herbal families in the world and is famous for its aromatic and polyphenolic biomolecules that can be utilised as reducing and stabilising agents during the synthesis of ZnO NPs. This review will go over the synthesis and how synthesis parameters affect the Lamiaceae-derived ZnO NPs. The Lamiaceae-mediated ZnO NPs have been utilised in a variety of applications, including photocatalysis, antimicrobial, anticancer, antioxidant, solar cells, and so on. Owing to their optical properties, ZnO NPs have emerged as potential catalysts for the photodegradation of organic dyes from wastewater. Furthermore, the low toxicity, biocompatibility, and antibacterial activity of ZnO against various bacteria have led to the application of ZnO NPs as antibacterial agents. Thus, this review will focus on the application of Lamiaceae-mediated ZnO NPs for the photodegradation of organic dyes and antibacterial applications.

In Vitro Antimicrobial and Anticancer Peculiarities of Ytterbium and Cerium Co-Doped Zinc Oxide Nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) are a promising platform for their use in biomedical research, especially given their anticancer and antimicrobial activities. This work presents the synthesis of ZnO NPs doped with different amounts of rare-earth ions of ytterbium (Yb) and cerium (Ce) and the assessment of their anticancer and antimicrobial activities. The structural investigations indicated a hexagonal wurtzite structure for all prepared NPs. The particle size was reduced by raising the amount of Ce and Yb in ZnO. The anticancer capabilities of the samples were examined by the cell viability MTT assay. Post 48-h treatment showed a reduction in the cancer cell viability, which was x = 0.00 (68%), x = 0.01 (58.70%), x = 0.03 (80.94%) and x = 0.05 (64.91%), respectively. We found that samples doped with x = 0.01 and x = 0.05 of Yb and Ce showed a better inhibitory effect on HCT-116 cancer cells than unadded ZnO (x = 0.00). The IC50 for HCT-116 cells of Ce and Yb co-doped ZnO nanoparticles was calculated and the IC50 values were x = 0.01 (3.50 µg/mL), x = 0.05 (8.25 µg/mL), x = 0.00 (11.75 µg/mL), and x = 0.03 (21.50 µg/mL). The treatment-doped ZnO NPs caused apoptotic cell death in the HCT-116 cells. The nanoparticles showed inhibitory action on both C. albicans and E. coli. It can be concluded that doping ZnO NPs with Yb and Ce improves their apoptotic effects on cancer and microbial cells.

Sol-Gel Synthesis of ZnO Nanoparticles Using Different Chitosan Sources: Effects on Antibacterial Activity and Photocatalytic Degradation of AZO Dye

Chitosan was used in the sol-gel synthesis of zinc oxide nanoparticles (ZnO NPs) as a capping agent in order to control the size, morphology, optical bandgap, photocatalytic efficiency, and antimicrobial activity. Different chitosan sources were used for the sol-gel synthesis of ZnO NPs, namely chitosan of shrimp shells, crab shells, and Streptomyces griseus bacteria. The photocatalytic efficiency was studied by using the methylene blue (MB) photodegradation test, and the antibacterial activity of the different types of ZnO NPs was investigated by the agar well diffusion technique. The particle size of ZnO NPs varied between 20 and 80 nm, and the band gap energy ranged between 2.7 and 3.2 eV. Due to the different chitosan sources, the ZnO NPs showed different antibacterial activity against Listeria innocua, Bacillus Subtiliis, Staphylococcus Aureus, Salmonella Typhimurium and Pseudomonas Aeruginosa. The ZnO NPs with lower band gap values showed better antibacterial results compared to ZnO NPs with higher band gap values. The MB dye removal of ZnO (shrimp shells), ZnO (crab shells), and ZnO (Streptomyces griseus) reached 60%, 56%, and 44%, respectively, at a contact time of 60 min, a low initial MB dye concentration of 6 × 10−5 M, a solution temperature of 25 °C, and a pH = 7.

Study of biogenic fabrication of zinc oxide nanoparticles and their applications: A review

• Focus on the advantages of biogenic synthesis of ZnO nanoparticles. • Characterization of biogenic synthesized ZnO nanoparticles. • Photocatalytic efficacy of biogenic synthesized ZnO nanoparticles. • Antimicrobial efficiency of synthesized ZnO NPs towards bacterial and fungal strain. Nanotechnology offers the synthesis and utilization of matter with Nano-scale size. The Nanoscale dimension gives nanoparticles a high SA/V (Surface area to Volume) proportion and because of this, it shows remarkable properties. Nowadays tremendous research is carried out on zinc oxide nanoparticles (ZnO NPs) because of their high bandwidth and maximum binding energy. ZnO NPs have different biological applications such as antimicrobial, antioxidant, photocatalytic, anti-diabetic, anti-inflammatory, wound healing, and optic properties. In the physical and chemical method of synthesis of ZnO NPs, there is the use of different toxic chemicals which is harmful and also causes deterioration of the environment over these conventional methods, green synthesis approach utilizes bacteria, algae, fungus, and plants. This review is a complete investigation of the use of different biological sources utilized for the synthesis of ZnO NPs and characterization studies of ZnO NPs and their potential applications.

Synthesis of zinc oxide nanoparticles mediated by Dictyota dichotoma endophytic fungi and its photocatalytic degradation of fast green dye and antibacterial applications

• Seaweed was collected from Ramanathapuram coastal area and the endophytic fungus was isolated. • ZnO nanoparticle was synthesized by utilizing extra cellular products of fungal endophytes is not yet predicted. • ZnO NPs show the high efficacy of antimicrobial and antibiofilm activity. • Excellent photocatalytic dye degradation was observed in the ZnO NPs treated samples. Biosynthesis of nanoparticles has received considerable importance because of their ecofriendly, cost effective and wide applications in biological fields. Aim of this study is to synthesis zinc oxide nanoparticle (ZnO NPs) using extra cellular product from isolated marine ( Dictyota dichotoma ) endophytic fungi Aspergillus sp (Accession number - MZ467123) . The properties of synthesized ZnO NPs have been characterized by UV–Vis spectrophotometer, FTIR, Field Emission Scanning Electron Microscope (FE-SEM), and Energy Dispersive X-Ray (EDX). The UV photoluminescence study exhibited the absorbance peak at the resonance of 270 nm which confirms the presence of ZnO NPs in the aqueous solution. The perfect sphere shape with ∼80–100 µm in size of ZnO NPs has been observed under FESEM and confirmed the presence of elemental composition of nanoparticles by EDX. The synthesized nanoparticles showed potential dye degradation efficiency (∼90%) under photo illumination. In addition, ZnO NPs have shown significant antibacterial effects in terms of zone of inhibition and antibiofilm activity against pathogenic bacteria. Fig. Schematic representation of ZnO NPs synthesis, characterization and its biological activities.

A review on biogenic green synthesis of ZnO nanoparticles by plant biomass and their applications

Nanobiotechnology has recently gained prominence as a fundamental branch of modern science and a novel epoch in the field of material researches. Due to a wide range of applications it attracts attention of many scientists from all over the world. Bionanomaterials are prepared using a variety of physical, chemical, and biological techniques and methods. Many different metal and metal oxide nanoparticles are reported to be produced by biological systems, including bacteria, fungi, actinomycetes, yeasts, viruses, and plants. Among all of them, biocompatible zinc oxide nanoparticles (ZnO NPs), obtained through biosynthesis with the aid of plant-derived materials, appears to be a highly successful way to create a fast, clean, non-toxic, and environmentally friendly platform for the production and application of these bionanomaterials. This review focuses on the plant extract-derived ZnO NPs synthesis, with a special emphasis on the recent advances and applications of these nanomaterials.

Green synthesis of zinc oxide nanoparticles using Sea Lavender (Limonium pruinosum L. Chaz.) extract: characterization, evaluation of anti-skin cancer, antimicrobial and antioxidant potentials

In the present study, a green, sustainable, simple and low-cost method was adopted for the synthesis of ZnO NPs, for the first time, using the aqueous extract of sea lavender, Limonium pruinosum (L.) Chaz., as a reducing, capping, and stabilizing agent. The obtained ZnO NPs were characterized using ultraviolet–visible spectroscopy (UV–VIS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The UV–Vis spectra of the green synthesized ZnO NPs showed a strong absorption peak at about 370 nm. Both electron microscopy and XRD confirmed the hexagonal/cubic crystalline structure of ZnO NPs with an average size ~ 41 nm. It is worth noting that the cytotoxic effect of the ZnO NPs on the investigated cancer cells is dose-dependent. The IC50 of skin cancer was obtained at 409.7 µg/ml ZnO NPs. Also, the phyto-synthesized nanoparticles exhibited potent antibacterial and antifungal activity particularly against Gram negative bacteria Escherichia coli (ATCC 8739) and the pathogenic fungus Candida albicans (ATCC 10221). Furthermore, they showed considerable antioxidant potential. Thus, making them a promising biocompatible candidate for pharmacological and therapeutic applications.

Bryophyllum pinnatum leaf extract mediated ZnO nanoparticles with prodigious potential for solar driven photocatalytic degradation of industrial contaminants

In an era of environment-friendly development plant extract-based biological techniques for synthesizing nanoparticles have gained a lot of attention over traditionally famous chemical and physical synthesis techniques. In the present study we have synthesized biogenic zinc oxide nanoparticles (BPLE-ZnO NPs) using Bryophyllum pinnatum leaf extract, compared its native properties and solar-driven photocatalytic activity with chemically prepared ZnO nanoparticles (Chem-ZnO NPs). In order to characterize and compare the Chem-ZnO and BPLE-ZnO, various techniques were used, including UV–visible spectroscopy, x-ray diffractrometry, photoluminescence spectroscopy, field emission scanning electron microscopy, electron dispersive x-ray spectroscopy, fourier transform infrared spectroscopy, and zeta potential analyzer. The results revealed the formation of hexagonal wurtzite ZnO, with no significant difference between the two methods; however, the use of Bryophyllum pinnatum leaf extract in ZnO NPs synthesis resulted in reduced size, presence of biomolecules on its surface and better monodispersity than purely chemical synthesis. Further, the BPLE-ZnO NPs showed better efficiency in the solar-driven photocatalytic degradation of methylene blue (MB) dye compared to Chem-ZnO NPs. Under solar exposure at a dose of 0.50 mg/mL BPLE-ZnO, resulted in 97.31% photodegradation with a rate constant of 0.06 min−1 of 20 mg/L MB solution within just 60 min which was 9.51% higher compared to the Chem-ZnO NPs. The BPLE-ZnO NPs were also employed to investigate their solar-driven photocatalytic performance for degrading the pharmaceutical (Metronidazole and Amoxycillin) and textile pollutants (Methyl orange dye) under sunlight. The results show that Bryophyllum pinnatum leaf extract-mediated ZnO NPs have an excellent potential in solar-based photocatalytic applications.

Sustainable synthetic approach and applications of ZnO/r-GO in the adsorption of toxic Pb2+ and Cr6+ ions

Highlights • Tectona grandis leaves extract based synthesis of ZnO NPs. • Sono-chemical preparation of ZnO/r-GO and its characterisation using several analytical methods. • Utilisation of ZnO/r-GO in the removal of toxic Pb 2+ and Cr 6+ ions from contaminated water via adsorption. • Isothermal and kinetic studies. The current work presents a sustainable method for the synthesis of ZnO/r-GO material using Tectona grandis leaf extract. Leaf extract was used to synthesise ZnO nanoparticles (ZnO NPs). To synthesise ZnO/r-GO, reduced graphene oxide (r-GO) and ZnO NPs were incorporated under ultrasonic conditions. The characteristic bonds onto ZnO/r-GO were identified as O H, C O, C-Zn, Zn-O, and others. The ZnO/r-GO was analysed using several analytical methods and has been used to eliminate hazardous Pb 2+ and Cr 6+ ions from contaminated water via adsorption. Maximum decontamination has been achieved through optimization. The removal of 68.3 and 60.9 % at 60 min, 67.9 and 63.9 % at 100 mg dosage, and 98 and 88.5 % at optimal pH was recorded for Pb 2+ and Cr 6+ ions. The adsorption equilibrium findings were validated using various isotherm and kinetic models. Pb 2+ and Cr 6+ had the highest adsorption capacities of 16.261 and 10.718 mg/g, respectively. The pseudo second order rate constants (k 2 ) were found to be 2.738 and 3.415 g/mg/min for Pb 2+ and Cr 6+ ions. The regeneration study also revealed the potential of the ZnO/r-GO and, after the first cycle, the % removal has been found to be 77.9 and 73.2 % for Pb 2+ and Cr 6+ ions, respectively.

Green synthesis of ZnO nanoparticles by pineapple peel extract from various alkali sources

ABSTRACT Zinc oxide nanoparticles (ZnO NPs) are concerned as potential materials due to their wide-ranging applications. The green synthesis of ZnO NPs using of plant extract as capping agent has been attracted much of interest of reserachers. Pineapple peel wastes are aboundance in Thailand and its extract contained high levels of phytochemical compounds (flavonoids and their derivatives). In this study, pineapple extract was used as a capping agent in ZnO NP synthesis, and KOH and a lye solution were used as reducing agents for comparison. The XRD patterns exhibit pure-phase ZnO with high crystallinity. The averages of the most petite crystalline sizes obtained from the Scherrer equation calculation of the prepared ZnO powder are 64.61 and 65.41 nm for KOH solution and lye use, respectively. Fourier transform infrared (FTIR) spectroscopy confirmed the presence of ZnO particles and pineapple extract residue in the as-received powder. Scanning electron microscope (SEM) images and transmission electron microscope (TEM) images showed the nano-size of the synthesized particles. The flower-like ZnO-NPs from a 0.06 M zinc precursor and KOH solution exhibited fascinating optical properties. Finally, all the results showed that lye from wood ash could be applied in ZnO nanoparticle synthesis using pineapple peel extract.

Antioxidant and photocatalytic properties of zinc oxide nanoparticles phyto-fabricated using the aqueous leaf extract of Sida acuta

Abstract Nanoparticles have gained considerable attention during the present millennium due to its unique properties and usage of same in all the scientific fields. The present study was aimed to phyto-fabricate zinc oxide nanoparticles (ZnO NPs) from Sida acuta and evaluate its antioxidant and photocatalytic activity against the dye victoria blue (VB). The phyto-fabricated ZnO NPs when subjected for physico-chemical characterization showed an absorbance peak at 373 nm and was spherical in nature. Strong and well-distinguished sharp peaks were noticed in X-ray diffraction analysis with an average size of ∼32.82 nm calculated through Scherrer’s formula. The size was also authenticated through dynamic light scattering analysis and transmission electron microscopy. The Fourier transform-infrared spectroscopy confirmed that the phyto-constituents of the plant extract served as capping/stabilizing agents during the synthesis of ZnO NPs. The atomic force microscopy studies on morphology and geometrics of the synthesized particles indicated that particles were monodispersed with colour difference. In addition, the surface area of ZnO NPs measured by Braunauer–Emmett–Teller experimental studies for adsorption isotherms was found to be 7.364 m2·g−1. The antioxidant efficacy of the phyto-fabricated ZnO NPs offered concentration-dependent antioxidant activity with an IC50 value of 0.74 mg·mL−1. Further, the VB (9 mM) dye degradation studies using the phyto-fabricated ZnO NPs (0.75 g·L−1) resulted in dye degradation of 93% at 40 min in natural sunlight. Further, the reuse and recycling of the photocatalyst for dye degradation offered 70.25% dye degradation ability within 40 min exposure to sunlight at the fifth cycle of reusability thereby indicating effective dye degradation ability of the phyto-fabricated ZnO NPs from the aqueous leaf extract of S. acuta.