Synthesis Of Metal Oxide Nanoparticles Research Articles

Synthesis and characterization of phytochemical fabricated Ag doped ZnO nanoparticles with Ficus benghalensis and their enhanced antibacterial and photocatalytic applications

The use of various plant materials for the bio synthesis of metal oxide nanoparticles follows the principles of green chemistry since it minimizes the amount of chemicals used. In the present work, ZnO and Ag doped ZnO nanoparticles were synthesized utilizing aqueous leaf extract of Ficus benghalensis. The aqueous leaf extract was screened qualitatively for the presence of chemical constituents. The nanoparticles ZnO, green modified ZnO and Ag doped ZnO were characterized by X-ray diffraction (XRD), FT-IR, EDAX and Scanning Electron Microscope (SEM). The optical properties were studied using UV-Vis-DRS spectroscopy and a bathochromic shift is observed in the band gap energy of synthesized Ag doped ZnO. From XRD, the particle size of the ZnO, green modified ZnO and Ag doped ZnO nanoparticles was found to be 36, 39 and 53 nm respectively. Photodegradation of crystal violet dye was studied by UV-Visible spectroscopy. The degradation ability of the surface modified ZnO was found to be more efficient than that of bare ZnO and green modified ZnO nanoparticles. The photocatalytic reactions obeyed pseudo-first-order kinetics according to Langmuir- Hinshelwood model. The reuse of nanoparticles for photocatalytic activity was also studied.

Supercritical Hydrothermal Reactions for Material Synthesis

Abstract Since the early 1990s, Adschiri and his colleagues have performed research on the use of supercritical water in diverse applications, including heavy oil reforming, waste polymer decomposition and chemical raw materials recovery, cellulose hydrolysis and sugar recovery, lignin decomposition and chemical raw materials recovery, and nanoparticle synthesis. Regarding inorganic materials synthesis, they invented supercritical hydrothermal synthesis for the continuous flow synthesis of metal oxide nanoparticles, which has already found worldwide industrial applications. They proposed a two-fluid mixing flow system where an aqueous metal salt solution is mixed with supercritical water to heat the solution to the supercritical state within a very short time, that is not attainable by conventional reactor systems. Organic-inorganic hybrid nanoparticles synthesis was demonstrated in the supercritical state, realizing homogeneous phase formation of organic molecules at high loadings. By optimizing the reaction conditions, small facet-controlled nanoparticles with narrow particle size distribution can be obtained. Organic modification of nanoparticles is shown to be effective for fabricating highly concentrated nanohybrid polymers or nano inks. Furthermore, these synthesized facet-controlled nanoparticles show high catalytic activities. Indeed, it is demonstrated that steam reforming of heavy oils or biomass wastes (black liquor) can occur in water even at low temperatures.

Electroanalytical sensors-based biogenic synthesized metal oxide nanoparticles for potentiometric assay of pantoprazole sodium

ABSTRACT Two modified coated membrane sensors were designed and tested. Pantoprazole-phosphotungstate was prepared by a reaction of pantoprazole with phosphotungstic acid in the solvent mediator o-nitrophenyloctyl ether. Two metal oxide nanoparticles nickel oxide and iron oxide nanoparticles, were synthesized from green sources Matricaria recutita flowers and Salvia officinalis leaves extracts, respectively. These nanoparticles were used for the potentiometric assay of pantoprazole sodium in the authentic sample and commercial products. The results showed that the improved nickel oxide and iron oxide nanosensors exhibited linearity using the concentration range of 1.0 × 10−9–1.0 × 10−2 and 1.0 × 10−10–1.0 × 10−2 mol L−1, respectively compared with 1.0 × 10−6–1.0 × 10−2 mol L−1 for the normally coated sensor. The lower limits of detection (7.6 × 10−6, 2.3 × 10−10, 2.8 × 10−11 mol L−1) and quantification (1.0 × 10−6, 1.0 × 10−9, 1.0 × 10−10 mol L−1) were determined for each of the three proposed sensors. Least squares calculations gave EmV = (27.266 ± 0.5) log (pantoprazole) + 433.37, EmV = (30.967 ± 0.3) log (pantoprazole) + 432.24 for the enriched nano-metal oxides, and EmV = (26.642 ± 0.6) log (pantoprazole) + 443.69 for the conventional type, respectively with correlation coefficients around 0.999 for the proposed sensors. The accuracy and precision of the modified potentiometric systems were estimated and the results showed excellent validity and suitability for the determination of pantoprazole in an authentic sample.

Green synthesis of various metal oxide nanoparticles for the environmental remediation-An overview

In the recent days the word “Green” is taking revolutionary rounds in the field of research to save the earth planet from environmental pollution. Green synthetic reactions help in reducing the unwanted and hazardous byproducts formation during the reaction. Using ideal solvents and nontoxic chemicals can uplift the environment friendliness in terms of pollution. Since the existing inorganic methods are not effectively removing pollutants, Bioremediation with bacteria, Fungi, plants, fungi etc are found to be the efficient approach methods in removing pollutants. Hence in this paper we would like to summarize the green synthesis of metal oxide nanoparticles from various plant tissues for the effective environmental remediation. From the literature it is found that iron based nanoparticles has many potential applications for the environmental remediation.

Green synthesis of multifunctional MgO@AgO/Ag2O nanocomposite for photocatalytic degradation of methylene blue and toluidine blue.

Introduction: In this paper, MgO@AgO/Ag2O nanoparticles were greenly synthesized, the current idea is to replace the harmful chemical technique with an ecofriendly synthesis of metal oxide nanoparticles (NPs) utilizing biogenic sources. Methods: The current investigation was conducted to create silver oxide NPs decorated by MgO NPs (namely, MgO@AgO/Ag2O nanocom-posite) using the leaves extract of Purslane (Portulaca Oleracea) as the reducing and capping agent. The nanopowder was investigated by means of X-ray diffraction, scanning electron mi-croscope, BET surface area, Fourier transform infrared, and UV-vis spectrophotom-eter studies. XRD studies reveal the monophasic nature of these highly crystalline silver nano-particles. SEM studies the shape and morphology of the synthesis AgO/Ag2O and MgO@AgO/Ag2O NPs. The presence of magnesium and oxygen was further confirmed by EDS profile. Results and discussion: The surface area was found to be 9.1787 m2/g and 7.7166 m2/g, respectively. FTIR analysis showed the presence of specific functional groups. UV-vis spectrophotometer studies show the absorption band at 450nm due to surface plasmon resonance. The results have also indicated the high performance of the greenly synthesized AgO/Ag2O NPs and MgO@AgO/Ag2O NPs for photocatalytic activity dye degradation (methylene blue and toluidine blue).

Anticancer activity of pure and silver doped copper oxide nanoparticles against A549 Cell line

In day-to-day life, green synthesis of metal oxide nanoparticles has still now achieved excellent heed in the field of anticancer activity. In this present study, Moringa oleifera leaf extract functions as reducing, capping, and stabilizing agents for the preparation of pure and silver doped copper oxide nanoparticles of various (5%, 10%, 15%, and 20%) concentrations. The synthesized materials were subjected to various characterization techniques. XRD, reveals that nanoparticles are in the monoclinic phase and the mean crystallite size for pure and Ag-doped CuO nanoparticles of various concentrations is found to be in the range of 15.22–3.67 nm. SEM images show that nanoparticles are relieved from particle size enlargement and EDAX analysis confirmed the existence of elements like Cu, O, and Ag. The biomolecules present in the leaf extract that helps for the bio-reduction of CuO nanoparticles were identified by FT-IR spectrometer. From UV–vis absorption spectra, peaks from 210 to 240 nm were observed. Furthermore, it also exhibits that if the concentration of silver doping increases there will be an increase in the energy bandgap. By MTT assay, the powerful cytotoxic activity for the synthesized pure and Ag-doped CuO nanoparticles of different concentrations has been probed against human lung cancer A549 cells. Among that, 20% of Ag-doped CuO nanoparticles showed a decrease in cell viability with an IC50 value of 15 µg/mL. After treatment with green synthesized nanoparticles, the cell death was assessed through three types of assessments which include AO/EB dual staining, Hoechst staining, and DCFH-DA staining assays in the cell line. The results betrayed that through apoptosis induction, the tested samples treated against human lung cancer A549 cells showed inhibition in cell proliferation and enhances morphological, and cytological alterations via an increased level of ROS accumulation in the NSCLC cell line.

NaHCO3 assisted multifunctional Co3O4, CuO and Mn2O3 nanoparticles for tartrazine removal from synthetic wastewater and biological activities

Wastewater treatment as well as biological activities require efficient and cost-effective alternative materials which motivates the interest of scientists for different types of nanomaterials. Nanomaterials are the best class of materials which can be used as adsorbents to treat wastewater and equally can be utilized as antioxidant, antimicrobial agents. The present study involves the synthesis of metal oxide nanoparticles (Co 3 O 4 , CuO and Mn 2 O 3 NPs) by hydrothermal approach followed by thermal decomposition of their respective metal carbonates at their scrupulous decomposition temperature. The prepared NPs were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The porous, spherical/irregular texture of prepared NPs was confirmed by SEM. Further, XRD analysis validated the formation of smaller size crystals of pure Co 3 O 4 , CuO and Mn 2 O 3 NPs. Thermal stability of as prepared Co 3 O 4 , CuO and Mn 2 O 3 NPs was investigated by TGA. The adsorptive behaviour of all the three NPs was investigated against the removal of an azo dye tartrazine (TZ). The optimum conditions for TZ removal were investigated using well established adsorption parameter like pH, shaking speed, temperature, initial TZ concentration and contact time. The maximum Langmuir adsorption capacity of TZ onto Co 3 O 4 , CuO and Mn 2 O 3 NPs was found to be 204.3, 184.7 and 177.6 mg/g respectively. Langmuir, Freundlich and Temkin adsorption isotherms were applied to TZ adsorption data and results indicated that the Freundlich model was best fitted having higher correlation factor (r 2 ) indicating multilayer adsorption. Kinetic studies revealed that TZ adsorption onto all three NPs was better descried by pseudo-second-order (PSO) kinetic model. Antimicrobial nature of Co 3 O 4 , CuO and Mn 2 O 3 NPs was studied against fungal and bacterial strains via disk diffusion method and CuO NPs were found with highest inhibition (31 mm and 20 mm) against Staphylococcus aureus and Candida albicans . Antioxidant behaviour of Co 3 O 4 , CuO and Mn 2 O 3 NPs was observed against DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical and highest inhibition (66%) of Co 3 O 4 was observed as compared to Mn 2 O 3 , CuO. In short, these multifunctional NPs can be used for pollutant removal and equally can be utilised for biological activities.

Fabrication of novel buckypaper metal oxide nano-catalysis glycerol carbonate/MWCNTs membrane for efficient removal of heavy metals

This study describes the fabrication of novel buckypaper membranes through the dispersion of multi-walled carbon nanotubes (MWCNTs) in the presence of surfactants metal oxide nano-catalysis Zinc oxide and magnesium oxide (ZnO and MgO) glycerol carbonate separately. Following vacuum filtration of the scattered solutions, self-supporting membranes known as buckypapers (BPs) were produced. The suggested membranes were employed for the efficient removal of heavy metals. The obtained data indicated that the incorporation of both glycerol carbonates prepared by two different nano metal oxides enhanced the permeability of MWCNTs membranes rejection efficiency. The characterization of the synthesized metal oxide nanoparticles, as well as the physicochemical and morphological properties of the membranes, were investigated. The rejection capabilities of membranes for the heavy metal ions were examined. Moreover, the suggested MWCNTs/ZnO nano-catalyst glycerol carbonate BP membrane displayed high rejection efficiency for heavy metals (Cd2+, Cu2+, Co2+, Ni2+, and Pb2+) than that prepared from the MgO nano-catalyst one.

Mesoporous silica encapsulating ZnS nanoparticles doped Cu or Mn ions for warning clothes

Mesoporous nanocapsules originated from silica encapsulated ZnS doped with metal oxide (Cu or Mn) were assembled and characterized. The morphological characterization was performed using Fourier-transform infrared spectroscopy (FTIR), UV–visible absorption spectra, and transmission electron microscopy (TEM). The analyses findings proved the structures of the synthesized metal oxide nanoparticles. It was verified that those metal nanoparticles are doped in the silica mesopores with an average particle size of 10–50, 30, 40, and 200 nm for ZnS, Zn doped Cu+2, Zn doped Mn+2, and silica, respectively. The morphological characterization of the cotton fabrics treated with the prepared mesoporous nanocapsules has been carried out by scanning electron microscopy (SEM). The mechanical and physical properties, antibacterial activity, and UPF measurements were also explored. The analyses results confirmed that the silica-encapsulated ZnS doped with metal ions imparts excellent antibacterial activity and ultraviolet protection to the cotton fabric that is distracted by physical or mechanical properties.

What is the role of phytochemical compounds as capping agents for the inhibition of aggregation in the green synthesis of metal oxide nanoparticles? A DFT molecular level response

To control the size of metal oxide nanoparticles, capping agents are often employed in the green synthesis of metal oxide nanoparticles. To guide the role of phytochemical-based capping agents, the interactions between the phytochemicals and nanoparticles have been investigated by DFT method. For this purpose, aucubin, an iridoid glycoside compound, was selected as a model. In this work, an in-depth analysis of the interactions between aucubin and ZnO nanoparticles with different sizes were conducted in gas and water phases. The adsorption Gibbs free energies of all bio-nanocomposites with different sizes were observed to be negative, which indicates the spontaneous nature of the adsorption process. The Eg and Gibbs free energy values of aucubin was found to depend on the size of ZnO nanoparticles. The bio-nanocomposite aucubin-(ZnO)6 has the most negative Gibbs free energy due to the formation of four hydrogen bonds between the aucubin and the nanoparticles. The evaluation of charge decomposition analysis showed that the direction of charge transfer is from aucubin to ZnO. Indeed, we found that both the vdW and electrostatic interactions are present in ZnO-aucubin bio-nanocomposites. The molecular level information provided in this work can be considered as a model for using phytochemicals as capping agents in green synthesis of nanoparticles.

Characterization of green route synthesized zinc oxide nanoparticles using Cyperus rotundus rhizome extract: Antioxidant, antibacterial, anticancer and photocatalytic potential

Cyperus rotundus rhizome has been employed in traditional Chinese and Indian Ayurvedic herbal formulations. Green synthesis of metal oxide nanoparticles has gained significant attention due to its economic, biocompatibility, non-toxicity and eco-friendliness. The current study confirmed the biosynthesized zinc oxide nanoparticles (ZnONPs) by an ultraviolet–visible absorption spectrum of 353 nm. Fourier transform infrared spectroscopy analysis demonstrated that bioactive functional groups served as reducing and stabilizing agents for ZnONPs. Further, X-ray powder diffraction (XRD) patterns showed crystalline nature with a hexagonal phase and strongly correlated with JCPDS file number 36-1451. The electron microscopic studies revealed irregular spherical particles with a size range of 17–100 nm and EDAX analysis validated the crystalline purity of ZnONPs. The average size of the ZnONPs determined by dynamic light scattering was 95.89 nm and the zeta potential was −12.1 mV, indicating stability of the particles. Moreover, the ZnONPs exhibited noticeable antioxidant potential by scavenging free radicals on DPPH (59.74%), ABTs (66.35%), nitric oxide (65.75%) and reducing power (63.94%) in a dose-dependent manner. The bacterial cell damages were observed through FESEM, confirming the antibacterial efficacy of ZnONPs. Further, the ZnONPs exhibited remarkable cytotoxic effect (62.34 μg/mL) against breast cancer cells and subsequent fluorescence staining demonstrated apoptotic and necrotic features in damaged cells. The photocatalytic effectiveness of ZnONPs demonstrated increased eco-bioremediation capabilities by degrading crystal violet (80.69%) and methylene blue (88.93%) dyes. Thus, this is the first report on ZnONPs synthesized using C. rotundus could be explored as a promising material for biological and photocatalytic applications.

Synthesis of metal oxide nanoparticles by facile thermal decomposition of new Co(II), Ni(II), and Zn(II) Schiff base complexes- optical properties and photocatalytic degradation of methylene blue dye

Three new Co(II), Ni(II), and Zn(II) complexes of tridentate ONN ligand were synthesized from the reaction of 2-amino-3-hydroxypyridine and pyrole-2-carboxyaldehyde and characterized using physio-chemical and analytical methods such as NMR, elemental analyzer, FT-IR, ESI-MS, and magnetic moment measurement. The collected data indicated that prepared complexes have metal:ligand ratio of 1:1 and octahedral geometry for Co(II) and Ni(II) while tetrahedral geometry for Zn(II) complex. The synthesized complexes are utilized as precursors for synthesizing Co3O4, NiO, and ZnO NPs by thermal decomposition at 600 °C, and their structures were defined by PXRD, SEM, UV-DRS, FT-IR, and EDAX. By using Scherrer equation, the average crystallite size calculated for Co3O4, NiO, and ZnO nanoparticles are 22, 18, and 24 nm, respectively. The energy band gap of Co3O4, NiO, and ZnO nanoparticles are 1.67, 3.34, and 3.12 eV, respectively, according to the Tauc baseline calculation, revealing their semiconducting nature. Co3O4, NiO, and ZnO nanoparticles were employed for photocatalytic degradation of methylene blue dye in sunlight. After 105 min., the maximum percentage of MB dye degradation for Co3O4, NiO, and ZnO was found to be 80 %, 81.2 %, and 86.68 %, respectively.

Synthesis of Metal Oxide Nanoparticles by Thermal Decomposition of a Ni(II) Complex and its Antimicrobial Activity

Synthesis of Metal Oxide Nanoparticles by Thermal Decomposition of a Ni(II) Complex and its Antimicrobial Activity

Green method for synthesis and characterization of copper oxide nanoparticles using Mulberry plant extract and their antibacterial, antioxidant and photocatalytic activity

The green synthesis of metal oxide nanoparticles is treated to be an eco-friendly path and cost-effective. Mulberry plant extract was used to synthesize CuO nanoparticles in this study. UV spectroscopy absorbance at 370 nm was used to analyze the resulting synthesized nanoparticles. The distribution of nanoparticles and particle sizes were discovered to be in the range of 40–60 nm using scanning electron microscopy. The polydisperse entity of CuO nanoparticles was revealed by TEM morphology and their SAED pattern rings. The plant bio-compounds and nanoparticles reaction involved functional groups were determined from FTIR analysis. Copper nanoparticles have characteristic diffraction peaks in the x-ray diffraction spectrum at 38.81°, and 66.35° which correspond to lattice planes (1 1 1) and (2 0 2), respectively. The organic dye pollutants of MB degraded in 90% at 40 min under visible light irradiation. The antioxidant and antibacterial activity of the CuO nanoparticles was tested against gram-positive and gram-negative microorganisms. The results support the hypothesis that green synthesized CuO nanoparticles could be a viable treatment option for diseases caused by microbial pathogens. This fact-finding result is that Mulberry plant extract-based green synthesized CuO nanoparticles destroyed or considerably inhibited pathogen activity, as well as having high antioxidant activity.

Antibacterial Assessment of Biofabricated Magnesium Oxide Nanoparticles (MgO NPs) using Conocarpus erectus Leaf Extract

Nanobiotechnology is a proficient technology that concers with nano scale materials in several scientific fields such as nanotechnology, chemistry, medicines and biotechnology. A swift and sustainable synthesis of metal oxide nanoparticles by exhausting natural sources is the present-day trend being used instead of lethal biochemical methods. This study prsent the first report for the use of medicinal plant of Conocarpus erectus as an ecofriendly regent in the synthesis of CuO NPs using copper sulphate as a starting material. Conocarpus erectus leaf extract was used as a bioreductor as wll as a capping agent in the manufacturing of MgO NPs. The structure and morphology of prepared MgO NPs were characterized byXRD, UV, FTIR, HRTEM, SEM and EDX analysis. The UV-Vis measurment confimrd the formation of MgO NPs by giving SPR peak at 261 nm. The attendance of various functional groups in Conocarpus erectus leaf extract liable for the development and stabilization of MgO NPs were confirmed by FTIR analysis. XRD measurement confirmed the crystaline f.c.c structure of MgO NPs. HRTEM and SEM studies exhibited the small size, spherical shape and uniformly dispersed magnesium oxide nanoparticles. EDX profile further authorized the elemental composition of the synthesized nanoparticles. The biosynthesized MgO NPs were assessed for the embarrassment of bacteria. Furthermore, plant capped MgO NPs have high inhibition efficiency against S. aureus and E. coli with inhibition zones of 17 mm and 16 mm respectively.

AND logic gate supported novel speckled phosphorus-doped carbon dots decorated ZrO2/CaO/MgO sonocatalysts for efficient MB dye decolorization

Textile dyes are significant contributors to aquatic pollution in developing nations, and also the current pace of human-caused contamination of worldwide freshwater bodies is frightening. Herein, we report the sonocatalytic decolorization of the methylene blue (MB) dye using a novel synthesis of composite materials of zirconium oxide (ZrO2), calcium oxide (CaO), and magnesium oxide (MgO) nanoparticles (NPs) decorated by phosphorus-doped carbon dots (PCDs). The monoclinic phase of ZrO2 has shown the highest catalytic activity, thus imparting greater decolorization efficiency (DE) in the synthesized metal oxide nanoparticles (MONPs) decorated with PCDs (MONPs@PCDs). The sonocatalytic efficiency of MONPs@PCDs was evaluated using MB as the analyte molecule. We report DE of up to 99.54% via speckled PCDs decoration and synergistic effect in a short time of 30 min at just 20 kHz frequency. The sonocatalytic activity of MONPs@PCDs is AND logic gate supported and was found as ZCMO@PCDs (99.54%) > ZMO@PCDs (96.47%) > ZO@PCDs (94.68%) > ZCO@PCDs (93.40%). However, the sonocatalytic activity of MONPs was only ZCMO (11.21%) > ZMO (9.26%) > ZO (3.79%) > ZCO (2.92%), under identical experimental conditions. The synergistic effect in polymetallic systems opens new pathways to be explored in sonocatalysis. We confirmed the synthesis of PCDs and their speckled decoration on the surface of MONPs using scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The speckled nanocomposites, i.e., MONPs@PCDs, showed an enhanced and faster decolorization efficiency than the bare MONPs, as demonstrated by the kinetics studies as 101 fold increase in k values and 101 fold decrease in t1/2 values. Novelty statementNovel nanocomposites have been developed for MB dye decolorization using a low frequency of just 20 kHz and possessing 99.54–93.40% DE in only 30 min, thus may aid in industrial dye decolorization and the reuse of wastewater for environmental sustainability.

Green Approach to the Synthesis of Metal Oxide Nanoparticles Used As Alternative Remedy to Multidrug Resistance

The introduction of nanotechnology into our world has ushered in a slew of changes and provided a wealth of knowledge that has fuelled progress in many sectors of existence. Recent advances in nanotechnology have shown the importance of metal oxide nanoparticles due to their potentials in different sectors, particularly in nanomedicine and related biomedical fields. Metal oxide nanoparticles (MOx-NPs) such as titanium dioxide nanoparticles (TiO2-NPs), copper oxide, silicon dioxide, zinc oxide and Iron oxide have gained a lot of prominence as a result of their unique properties. Metal and MOx-NPs based nanoparticles are being employed to create a novel antibacterial drug formulation, which is a revolutionary and ground breaking method to drug discovery and development. Different methods are employed for the synthesis of these nanoparticles of which green synthesis is found to be a better option. It involves the use of plant extracts which is a non-toxic solvent. Green materials offer a variety of advantages, such as low energy consumption and the capacity to operate under moderate operating conditions (such as pressure and high temperature) without the use of harmful chemicals or catalysts. Therefore, more research efforts should be geared toward the advancement of this important technology.

A Review on Green Synthesis of Nanoparticles and Their Diverse Biomedical and Environmental Applications

In recent times, metal oxide nanoparticles (NPs) have been regarded as having important commercial utility. However, the potential toxicity of these nanomaterials has also been a crucial research concern. In this regard, an important solution for ensuring lower toxicity levels and thereby facilitating an unhindered application in human consumer products is the green synthesis of these particles. Although a naïve approach, the biological synthesis of metal oxide NPs using microorganisms and plant extracts opens up immense prospects for the production of biocompatible and cost-effective particles with potential applications in the healthcare sector. An important area that calls for attention is cancer therapy and the intervention of nanotechnology to improve existing therapeutic practices. Metal oxide NPs have been identified as therapeutic agents with an extended half-life and therapeutic index and have also been reported to have lesser immunogenic properties. Currently, biosynthesized metal oxide NPs are the subject of considerable research and analysis for the early detection and treatment of tumors, but their performance in clinical experiments is yet to be determined. The present review provides a comprehensive account of recent research on the biosynthesis of metal oxide NPs, including mechanistic insights into biological production machinery, the latest reports on biogenesis, the properties of biosynthesized NPs, and directions for further improvement. In particular, scientific reports on the properties and applications of nanoparticles of the oxides of titanium, cerium, selenium, zinc, iron, and copper have been highlighted. This review discusses the significance of the green synthesis of metal oxide nanoparticles, with respect to therapeutically based pharmaceutical applications as well as energy and environmental applications, using various novel approaches including one-minute sonochemical synthesis that are capable of responding to various stimuli such as radiation, heat, and pH. This study will provide new insight into novel methods that are cost-effective and pollution free, assisted by the biodegradation of biomass.

Green synthesis of magnesium oxide nanoparticles using leaves of Iresine herbstii for remediation of Reactive Brown 9 dye

<p>Nanotechnology is the newest and one of the most promising areas of research in modern medical sciences. Metal nanoparticles possess extraordinary optical, thermal, chemical properties and are being widely used in industrial, electronics, and biomedical fields. It has presented its potential to contribute to solving one of the greatest problems of the worldwide wastewater treatment issue. The approach of green synthesis of metal oxide nanoparticles seems to be a cost-efficient, eco-friendly, and easy alternative approach. The current study deals with the synthesis and characterization of Magnesium Oxide nanoparticles (MgO-NPs) using leaves extract of Iresine herbsti. The characterization was done by XRD and SEM. Then MgO-NPs were applied for the remediation of Reactive Brown 9 dye following the optimization of reaction parameters (conc. of dye, conc. of nanoparticles, pH, and temperature). The maximum decolorization (95.8%) was obtained at 0.02% dye conc., 0.003 mg/L conc. of MgO-NPs, at pH 4, and temperature 40 °C. TOC and COD were used for mineralization assessment of studied dye samples and their values were found to be 88.56% and 85.34%, respectively. The magnesium oxide nanoparticles could be applied successively for the treatment of other problematic dyes as well.</p>

Investigation on Metal Nanoparticles: Nickel Oxide, Cuprous Oxide and Tin Ferrite with Their Humidity Sensing at Room Temperature

This paper deals with the facile approach to the synthesis of different metal oxide nanoparticles and their comparative study for humidity sensing application at room temperature. The synthesis of these metal oxide nanoparticles is through co-precipitation method for nickel oxide and tin ferrite and hydrothermal route for cuprous oxide. The SEM and EDX reveal the porous morphology and confirmed composition of the synthesized metal oxides. FTIR detects the presence of functional groups like –OH and confirms the inverse spinal structure in tin ferrite. The optical band gap was determined by UV spectroscopy: 3.86[Formula: see text]eV for NiO, 4.13[Formula: see text]eV for Cu2O, and 4.07[Formula: see text]eV for SnFe2O4. XRD gives the information about the average crystallite size for tin ferrite 2.42[Formula: see text]nm, cuprous oxide 12.88[Formula: see text]nm and nickel oxide 22.51[Formula: see text]nm as the size comes to nano range the surface area increases, which is a good indication for humidity sensing. The humidity sensing of materials was detected by electrical modes. The deposited thin films were prepared by spin coater and observed sensitivity of these films was 0.72[Formula: see text]M[Formula: see text]/%RH for NiO, 1.59[Formula: see text]M[Formula: see text]/%RH for Cu2O, and 2.07[Formula: see text]M[Formula: see text]/%RH for SnFe2O4. The experiments were repeated after few weeks and the aging effects of samples were found negligible which makes the sensor stable.