Synthesis Of Metal Oxide Nanoparticles Research Articles

Comparative analysis of the antimicrobial activity and dye degradation of metal oxides (TiO2, CdO, Mn2O3, and ZnO) nanoparticles using a green approach.

A tremendous amount of recent work has been done on different metal oxide nanomaterials for biological activities and photocatalytic dye degradation. This work used the Cissus quadrangularis leaf extract to prepare TiO2, CdO, Mn2O3, and ZnO nanoparticles using a green synthesis approach. To ascertain the physicochemical characteristics of the generated metal oxide nanoparticles, various characterisation techniques were used. The X-ray diffraction technique was used to determine the composition of the crystal and phase. Metal oxide nanoparticles have been proven to be present through surface morphological investigations using a scanning electron microscope and energy dispersive spectroscopy analysis. UV-Vis and Fourier transform infrared spectra were used for spectroscopic analysis. X-ray photoelectron spectroscopy can determine a material's elemental composition in addition to the electronicand chemicalstates of its atoms. The nanomaterial's distinct morphology, which resembles rods, rose petals, platelets, and spheres, was discovered by scanning electron microscope. Synthesized metal oxide nanoparticles have demonstrated a remarkable efficiency of 87.5-90.6% when utilized as a catalyst towards the removal of the malachite green dye under UV light irradiation. Additionally, we use the disc diffusion method to assess antibiotic efficacy against Bacillus subtilis, Candida tropicalis, and Escherichia coli. ZnO nanoparticles had the greatest zones of inhibition for 80 μL doses, measuring 26.99mm for Bacillus subtilis, 27.57mm for Escherichia coli, and 25.28mm for Candida tropicalis. The antimicrobial activity was strongly impacted by the size of the nanoparticles and increased with decreasing particle size. Overall, our research demonstrates that metal oxide nanoparticles are a promising photocatalytic agent for wastewater treatment and biological applications.

Synthesis and Characterization of Zirconia-Based Ceramics: A Comprehensive Exploration of Film Formation and Mixed Metal Oxide Nanoparticle Synthesis

Due to its strong ionic conductivity and superior mechanical qualities, zirconia-based ceramics are frequently used in electrochemical devices. Today, zirconium oxychloride octahydrate and ethanol have been developed for the purpose of reducing zirconium thin films on glass, single-crystal silicon p-type, substrates. The phase composition and properties of the films, as well as the physicochemical processes involved in film formation, have all been investigated. Zirconia mixed metal oxide nanoparticles with various physicochemical properties can be created using a variety of synthetic processes in conjunction with additional variables like concentration, PH, type of precursor utilized, etc. In order to create zirconia mixed metal oxide nanoparticles, many synthetic techniques, including sol-gel, hydrothermal, and coprecipitation methods are discussed in this article.

Bioefficacy of Zinc oxide nanoparticle synthesis and their Biological, Environmental applications from Eranthemum roseum

Synthesis of metal oxide nanoparticles using medicinal plants increasing rapidly due to its eco-friendly to environment. In this study Zinc oxide nanoparticle is synthesized using the leaf extract of plant E. roseum. Synthesized NPs was characterized using UV- Vis Spectroscopy analysis where the peak observed at 374 nm with band gap of 2.5 eV, FTIR and XRD analysis validate pure hexagonal structure, Spherical shape of NPs was confirmed by SEM with EDX analysis and main compounds are zinc 75 % and oxygen 22 %. Transmission Electron Microscopy Analysis confirms the oval shaped ZnO NPs Biological activity of E. roseum ZnO NPs such as antioxidant assay DPPH, ABTS, hydroxyl radical activity shows good inhibition against free radicals. The In-vitro Hypoglycemic effects has maximum inhibition of 96 % on α- amylase activity and 87 % on α- Glycosidase activity. Anti-inflammatory activity recorded 93 % maximum inhibition at Albumin denaturation assay and 75 % at Membrane stabilization assay. E. roseum ZnO NPs shows 67.79 % on HepG2 Anti-proliferative cells line. AO/EtBr staining assays confirms the apoptosis effect. Larvicidal activity shows highest mortality of 98.44 % on species C. quinquefasciatus. Photocatalytic dyedegradation of Methylene blue dye shows 65 % of dye degradation.

Degradation of Malachite Green Dye by Solar Irradiation Assisted by TiO2 Biogenic Nanoparticles Using Vaccinium corymbosum Extract

The green synthesis of metal oxide nanoparticles (NPs) offers an alternative to chemical procedures, which can be harmful to human health due to exposure to hazardous substances and harsh synthesis conditions. The following work synthesized titanium dioxide nanoparticles (TiO2 NPs) using a green synthesis method. As a precursor, food-grade TiO2 was used with blueberry extract. This approach makes the process safer, cheaper, and simpler, requiring minimal effort to achieve effective TiO2 NP synthesis. The TiO2 NP characterization was performed by solid-state techniques, such as Ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). According to the XRD diffractograms, TiO2 NPs were obtained in the anatase phase with incidence peaks of 25.28 (101). TEM confirmed their pseudo-spherical shape with an average size of 170 nm. The 3.2 eV bandgap of TiO2 NPs enables UV absorption, making them ideal for efficient photocatalytic degradation under sunlight. On the other hand, the photocatalytic activity of TiO2 NPs was examined using malachite green (MG) dye as a pollutant model under direct sunlight. After 30 min, a degradation of 94% was achieved. The kinetic analysis identified parabolic diffusion and modified-Freundlich kinetics as primary mechanisms, emphasizing diffusion and adsorption in electron transfer. The main reactive oxygen species (ROS) involved in the photodegradation of MG dye were h+ and OH•.

Dendrophthoe falcata extract mediated Fe3O4 nanoparticles: A functional agent for dye degradation and inflammation mitigation

The synthesis of metal oxide nanoparticles through green methods using plant extracts has garnered significant interest for their sustainable and multifunctional applications. In this study, the leaf extracts of Dendrophthoe falcata (D'falcata), a medicinal plant known for its rich phytochemical composition was successfully utilized as a reducing and stabilizing agent to synthesize Fe3O4 nanoparticles through a co-precipitation method. The D'falcata-mediated Fe3O4 nanoparticles were characterized using XRD, FTIR, UV–vis, SEM, EDAX, and TEM. The prepared nanoproduct was employed to decompose Congo red dye molecules through photocatalysis. XRD and FTIR analyses confirmed the cubic spinel phase of Fe3O4 nanoparticles and the Fe-O peak around 600 cm-1, while the UV–vis spectrum exhibited an absorption peak around 350 nm. Morphological studies revealed that the synthesized D'Fe3O4 nanoparticles were slightly agglomerated and ranged in size from 25 to 35 nm. The EDAX profile confirmed the presence of expected elements like Fe, O, and N in the final product. VSM studies indicated that D'Fe3O4 displayed paramagnetic behavior. Moreover, the anti-inflammatory assay demonstrated its potential for tumor therapy, with a percentage inhibition of 95 %, surpassing the standard diclofenac sodium (89 %). The smaller size of the D'falcata-mediated Fe3O4 nanoparticles also makes them a viable option for magnetic resonance imaging. Furthermore, photocatalytic studies showed the increase in dye degradation efficiency over the time. The findings from XRD, SEM, FTIR, and VSM analyses were well corroborated, highlighting the enhanced photocatalytic and anti-inflammatory activities of the synthesized D'Fe3O4 sample.

Green-synthesized CuO and ZnO nanoparticles derived from Calotropis gigantea (Apple of Sodom): enhancing plant growth, efficient dye removal, and potent antibacterial applications.

Nanoparticles, owing to their unique physicochemical properties, have garnered significant attention in various scientific disciplines, including materials science, chemistry, biology, and environmental engineering. In recent years, the synthesis of metal oxide nanoparticles, such as NiO, Fe2O3, ZnO, SnO2, and CuO via green routes, has gained attraction due to their diverse applications in fields ranging from catalysis and electronics to medicine and environmental remediation. This study focuses on the green synthesis of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles using Calotropis gigantea (Apple of Sodom) leaf extract as a reducing agent and stabilizer, with zinc nitrate (ZnNO3.6H2O) and copper nitrate (CuNO3.3H2O) as precursors. The hexagonal phase of ZnO and monoclinic plan structure of CuO with high crystallinity was confirmed by XRD and elemental composition by EDX analysis. With the help of an SEM image, particle size measured for CuO and ZnO using ImageJ software was found to be 56.08nm and 46.49nm, respectively. This study investigates the efficacy of nanoparticles in wastewater treatment, particularly focusing on methylene blue dye decolorization using the statistical processing of response surface methodology (RSM) using the Box-Behnken method. Additionally, it explores the impact of synthesized nanoparticles on seed growth enhancement, using Vigna radiata (green gram) seeds immersed in various doses of nanoparticles (0, 0.5, 1, 1.5, 2mg/30mL). Furthermore, the antibacterial activity of the nanoparticles against both gram-positive and gram-negative bacteria is evaluated. The results confirm the effectiveness of the materials for methylene blue dye removal, achieving 80.53% with CuO and 78.25% with ZnO. Significant seed growth was observed with a low nanoparticle dosage of 1.5mg/30mL, resulting in the highest seedling vigour index and germination percentage. This reduces the need for fertilizers and lessens environmental impact.

NiO nanoparticles by thermal decomposition of complex and evaluation of the structural, morphological, and optical properties

An efficient method for the synthesis of metal oxide nanoparticles (NPs) involves the solid-state thermal decomposition of precursor complexes. This study reports on the preparation of nanocrystalline nickel oxide (NiO) through a solid-state thermal decomposition of nickel(II) bis(N-methyl-N-paramethoxyphenyl dithiocarbamate) in a furnace. The novel Ni(II) complex was characterized using various analytical techniques. The single-crystal X-ray structure of the new nickel dithiocarbamate complex, C18H20N2NiO2S4, was determined and it showed a square-planar nickel coordination environment. The CH⋯S intramolecular hydrogen bond in this complex contributes to the planarity of the Nickel coordination environment. The complex underwent thermal decomposition in the air at about 750 °C for varying times of 90, 120, 150, and 180 min, resulting in the production of the oxide. Subsequently, the study explored how varying calcination times influenced the structural, morphological, and optical characteristics of the formed NiO nanoparticles. Face-centered cubic (FCC) structure of NiO NPs was confirmed whose crystallite size increased with an increase in the dwelling time of calcination and has been attributed to the possible coalescence of smaller crystallites to form larger ones. The confirmation of the face-centered cubic (FCC) structure of NiO nanoparticles was established, with the crystallite size observed to increase alongside longer calcination periods. This phenomenon has been linked to the potential amalgamation of smaller crystallites into larger ones. The optical energy bandgap decreased from 4.35 to 3.40 eV with an increase in the calcination time due to the increase in crystallite size occasioned by a longer reaction time from 90 to 180 min. These NPs will be useful as photocatalysts due to their high crystallinity and the capability to absorb within the visible region of the solar spectrum.

“Efficacy of datura metel leaf extract on MnSrO2 NPs synthesized using a green method in terms of pollutant reduction and antimicrobial activity.”

In this work, we prepared both chemical and biogenic synthesis of MnSrO2 (0, 5, 20 ml DLE) nanoparticles using datura metel leaf extraction by co-precipitation method and also prepared Sulfadiazine dye for catalytic activity. The applications and properties of green MnSrO2 nanoparticles have compared and they were characterized via XRD, SEM, FT-IR, EDX, UV–visible, and PL techniques. These nanoparticles showed an 18–8 nm diameter range, which was arranged in a spherical form combined randomly. The evidence from FTIR spectra showed peaks around 492, 487, 483, 655, 606, and 603 cm−1 for the creation of SrMnO2 NPs. Antibacterial activity of MnSrO2 (0, 5, 20 ml DLE) was measured by the well-diffusion method against pathogens, Staphylococcus aureus and Klebsiella pneumonia. The photocatalytic activity of the synthesized metal oxide nanoparticles was investigated by UV–visible spectroscopy for Sulfadiazine dye degradation with bare MnSrO2 NPs, g-MnSrO2 NPs [5 ml DLE], and g-MnSrO2 NPs [20 ml DLE] in presence of visible light irradiation.

Synthesis and characterization of Co3O4, CuO and NiO and nanoparticles: Evaluation of structural, vibrational, morphology and thermal properties

Green synthesis of CuO, NiO, and Co3O4 nanoparticles used biowaste (Gomutra). The physicochemical properties of metal oxide nanoparticles have been studied using various methods. Green synthesised metal oxide nanoparticle crystal properties were calculated using X-ray diffraction. It shows that all metal oxide crystallite sizes are nanoscale (27–31 nm). XRD spectra of CuO nanoparticles confirm their monoclinic structure, which matches JCPDS data. FTIR spectra reveal the existence of functional groups and associated vibrational modes in NiO and Co3O4 nanoparticles, confirming a cubic crystal structure with lattice parameters of 4.175 Å and 8.054 The surface appearance and particle size of three metal oxide nanoparticles were examined by SEM and TEM. XRD matches the average particle sizes of three metal oxide nanoparticles, which are 33–40 nm. Thermal stability of synthesized metal oxide nanoparticles was measured from 0 to 1000 °C using TG-DTA. It shows that the nanoparticles are stable and suited for various applications. Their unique properties make these metal oxide nanoparticles excellent for gas detection, antibacterial activity, photocatalysis, and biosensing.

Investigations on the microbial activity and anti-corrosive efficiency of nickel oxide nanoparticles synthesised through green route

Abstract Researchers have shown considerable interest in the environmentally friendly synthesis of several nanoparticles particularly metal nano particles due to their multifaceted applications. The target of the current research includes the synthesis of nickel oxide nanoparticles (NiO-NPs) through the green route using the bark extract from Acacia Nilotica, and analyzed their chemical and surface morphological features using XRD, SEM, EDX, IR, UV–vis and photoluminescence spectroscopy. In addition, the corrosion inhibition ability and antimicrobial activity of the extract were also studied. The XRD analysis indicated that the NiO exist in the form of nanoparticles. It showed the formation of pure cubic NiO-NP with a prominent peak at 43.28° reflected from the plane (200). The crystallite size was found to be 15.83 nm. The SEM micrographs revealed that NiO-NPs appeared to be a bulk cluster-like structure on their surface.The EDX analysis displayed the presence of Ni and oxygen atoms. The photoluminescence spectrum demonstrated that the green synthesized metal oxide nanoparticles have a modified emission band due to the presence of oxygen deficiencies and induced surface imperfections. The Fourier transform infrared spectroscopy (FTIR) confirmed the association of peaks with the C–H and Ni–O bonds. The UV–vis study showed a maximum absorption at 264 nm. A study on the inhibition efficiency towards microbes confirmed that the prepared NiO-NPs have a good inhibition against selected microbes such as S. aureus, E. coli, Candida albicans, A. Niger. The mass loss system showed restraint 93.68 % effectiveness in the mild steel, and the electrochemical study supported the formation of a defensive protective layer on the cathodic locales of the carbon steel surface inhibiting corrosion.

Exploiting of Green Synthesized Metal Oxide Nanoparticles in the Potentiometric Determination of Metformin Hydrochloride in Pharmaceutical Products.

The advanced and highly functional properties of Al2O3 and NiO nanoparticles promote the widespread use of metal oxides as remarkable electroactive materials for sensing and electrochemical applications. The proposed study describes a comparison of the sensitivity and selectivity of two modified wire membrane sensors enriched with Al2O3 and NiO nanoparticles with conventional wire membranes for the quantification of the antidiabetic drug metformin hydrochloride (MTF). The results show linear relationships of the enriched Al2O3 and NiO nanosensors over the concentration ranges 1.0 × 10-10-1.0 × 10-2 mol L-1 and 1.0 × 10-6-1.0 × 10-2 M for both the modified sensors and the conventional coated wire membrane sensors. The regression equations were EmV = (52.1 ± 0.5) log (MTF) + 729 for enriched nanometallic oxides, EmV = (57.04 ± 0.4) log (MTF) + 890.66, and EmV = (58.27 ± 0.7) log (MTF) + 843.27 with correlation coefficients of 0.9991, 0.9997, and 0.9998 for the aforementioned sensors, respectively. The proposed method was fully validated with respect to the recommendations of the International Union of Pure and Applied Chemistry (IUPAC). The newly functionalized sensors have been successfully used for the determination of MTF in its commercial products.

Biosynthesis of Cissus rotundifolia Stem-Mediated Titanium Dioxide Nanoparticles and Their Anticariogenic Activity against Streptococcus mutans and Lactobacillus sp.

ABSTRACT Introduction: The green synthesis of metal oxide nanoparticles using plant extracts has emerged as an eco-friendly method. Titanium dioxide nanoparticles (TiO2NPs) were synthesized using Cissus rotundifolia in this study. Titanium dioxide nanoparticles were utilized in restorative medicine for enhanced medicinal properties and in dental composites for their antimicrobial activities. Cissus rotundifolia is recognized as a medicinal plant due to its diverse properties, including mild laxatives, anti-inflammatory, and hyperglycemic activities. Materials and Methods: The antimicrobial activity of the prepared nanoparticles against Lactobacillus Sp. and Streptococcus mutans was evaluated using agar well diffusion method. The bactericidal and bacteriostatic activity of the prepared TiO2NPs was examined using time-kill kinetic analysis. Results: The prepared nanoparticles exhibited potential antimicrobial activity against Lactobacillus sp. (12 mm) at the highest concentration of 100 µg/mL. The prepared nanoparticles also exhibited excellent bactericidal activity against Lactobacillus Sp. and mild bacteriostatic activity against Staphylococcus mutans at the highest concentration of 100 µg/mL. Conclusion: The synthesized TiO2NPs showed significant antimicrobial activity against dental pathogens. The observed anticariogenic activity shows the potential of nanoparticles for dental applications. Hence, the prepared nanoparticles can be used in the field of dentistry as an antimicrobial agent instead of synthetic drugs causing more side effects.

Cyanobacteria Based Nanoformulation of Biogenic CuO Nanoparticles for Plant Growth Promotion of Rice Under Hydroponics Conditions.

Synthesizing nanoparticles through a green synthesis approach is common nowadays. Cyanobacteria have attained great importance in the field of biosynthesis of nanoparticles as there is no use of toxic chemicals as reducing or capping agents for the synthesis of metal oxide nanoparticles. Micronutrient-based nano-formulations have become a topic of great interest in recent times due to their various advantageous properties and applications in agriculture. The current study aims to exploit the potential cyanobacterial strains isolated from different locations such as freshwater and soil ecosystems. The potential cyanobacterial isolates were screened based on their multiple plant growth promoting (PGP) attributes such as Indol acetic acid (IAA) production, siderophores, and phosphate solubilization. After the screening of cyanobacteria based on multiple PGP activities, the cyanobacterial strain was identified at the species level as Pseudanabaena foetida RJ1, based on microscopy and molecular characterization using 16S rRNA gene sequencing. The cyanobacterial biomass extract and cell-free extracts are utilized for the synthesis of CuO micronutrient Nanoparticles (NPs). The cyanobacterial strain Pseudanabaena foetida RJ1 possesses plant growth-promoting (PGP) attributes that provide reduction and capping for CuO NPs. The synthesized NPs were characterized and subjected to make a nano-formulation, utilizing the cyanobacteria-mediated CuO NPs along with low-cost zeolite as an adsorbent. The application of cyanobacterial biomass extract and cell-free extract provided an excellent comparative aspect in terms of micronutrient NP synthesis. The NPs in the form of formulations were applied to germinated paddy seeds (Pusa Basmati -1509) with varying concentrations (5, 10, 15mg/l). Effects of cyanobacteria based CuO NPs on hydroponically grown paddy crops were analyzed. The application of nano-formulations has shown a significant increase in plant growth promotion in rice plants under hydroponics conditions. There is no such type of comparative investigation reported earlier, and NPs of micronutrients can be utilized as a new economic nanofertilizer and can be applied to plants for their growth promotion.

Evaluation of magnetic and electrochemical performance of copper oxide nanoparticles using Myristica fragrans (mace) extract

Abstract The synthesis of metal oxide nanoparticles using natural extract encourages the futuristic design of an environmentally friendly system by getting rid of the dangerous, toxic substances. The food industry in India is paying a lot of attention to Myristica fragrans, often known as mace, due to its rich medicinal significance. In the current study, M. fragrans (Mace) aqueous extract was used to prepare copper oxide (CuO) nanoparticles. Phytochemical screening confirms the presence of bioactive substances such as alkaloids, sterols, glycosides, and flavonoids in the extract. XRD and SEM measurements show that the nanoparticles have a monoclinic structure with polyhedral shape. Using the Debye-Scherrer formula, the material’s average crystallite size was found to be 85 nm. Based on the Tauc plot, an optical band gap of the prepared CuO NPs was calculated as 2.6 eV. At room temperature, the material’s magnetic property was investigated using VSM analysis. Congo red was used to examine the photocatalytic properties of the materials with various timings. CuO nanoparticles’ antibacterial activity was evaluated at various doses against Staphylococcus aureus and Klebsiella pneumoniae. Almost, CuO NPs exhibit better response against both the bacteria. Moreover, research investigations using cyclic voltammetry was carried out to assess the produced nanoparticles’ pseudocapacitive qualities. At a scan rate of 10 mV s−1, the material produced a good specific capacitance of 233.8 F/g with 1 M of KOH as an electrolyte.

Enhancing fermentation yield for biohydrogen production using eco-friendly nickel and cobalt ferrite nanoparticles

AbstractIn recent years, the sustainable metal oxide nanoparticle synthesis using various plant leaf extracts as reducing agents has gained significant attention in the field of renewable energy research. This study explores the biohydrogen yield enhancement potential of two types of nanoparticles derived from olive leaves. Synthesized nanoparticles are characterized by SEM, EDX, and FTIR spectrum analyses; these nanoparticles exhibit mean dimensions of 385 nm and 292 nm. Fermentation experiments were conducted using varying ratios of the two types of nanoparticles ranging from 50 to 500 mg/L to determine the impact of these nanoparticles on bio-hydrogen yield. Remarkably, with the usage of 200 mg/L of nickel ferrite nanoparticles boosted biohydrogen yield by 47%, while 200 mg/L of cobalt ferrite nanoparticles increased it by 41%. These findings highlight the potential of sustainably synthesized nanoparticles, especially those from olive leaves, as catalysts for enhancing biohydrogen production in dark fermentation processes. This research offers promising insights into eco-friendly bioenergy generation.

Natural grape juice assisted synthesis of metal oxide nanoparticles: Evaluation of microstructural, vibrational and colloidal stability analysis for Liquified Petroleum Gas (LPG) sensor applications

The current study used simple and cost-effective methods to generate Fe3O4, ZnO, NiO, and Co3O4 nanoparticles. Grape juice was chosen as a sustainable fuel along with metal nitrates. Green synthesised metal oxide nanoparticles' microstructure and colloidal stability were characterised using several methods. Metal oxide nanoparticle lattices and crystallite sizes were examined using X-ray diffraction. It shows that many metal oxide nanoparticles have 20–30 nm crystallite diameters. TEM captured metal oxide nanoparticle form and size. Additionally, these nanoparticles' particle size was determined and compared positively to XRD. Metal oxide nanoparticles have spherical, cubical, and plate-like exteriors. Absorption bands from O-H, N-O, C-H, N-O, and M-O bond stretching, bending, and lengthening were visible in the FTIR spectrum. Zeta potential tests demonstrate nanoparticle colloidal stability. Each of four metal oxide nanoparticles has a positive Zeta potential. Fe3O4 nanoparticles are more stable than other metal oxide nanoparticles (−58.7 mV). Metal oxide nanoparticles sensed many test gases well. Fe3O4 and ZnO nanoparticles have good LPG and ethanol detecting capabilities. The response-recovery time demonstrates that the produced metal oxide nanoparticles are appropriate materials for the ethanol gas sensor.

Green syhthesis of aluminium oxide nanoparticles using Chrysophyllum albidum, Terminalia catappa and Mimusops Coriacea leaf extracts for antibacterial and antifungal activities

The study reports an environmentally friendly and simple green technique for the synthesis of aluminium oxide nanoparticles (Al2O3 NPs). The leaf extracts of Chrysophyllum albidum (chry.A), Terminalia catappa (Alm) and Mimusops Coriacea (Lam) were used as reducing and stabilizing agents. Microscopic characterisations of the nanoparticles were carried out such as TEM, SEM, X-RAY, FTIR, UV and antimicrobial application were conducted. The result of the analysis showed that transmission electron microscopy (TEM) of Al2O3 NPs revealed quasi-spherical particle shapes and showed the particle size distribution. X-ray diffraction (XRD) analysis revealed that the Al2O3 crystals are face-centered cubic (FCC) for Chry.A Al2O3 NP, Alm Al2O3 NP and Lam Al2O3 NP and the average crystallite size were given to be 54.4 nm, 58.3 nm and 25.8 nm while Fourier transform infrared (FTIR) results of Al2O3 NPs showed the existence of metal-oxygen Al-O and occurrence of carbonyl and hydroxyl groups from plant flavonoids. The electronic interaction of Al2O3 NPs was investigated with Ultraviolet visible spectroscopy (UV) and the results revealed 238 nm of the absorption capacity of Al2O3 NPs which is attributed to quasi-spherical structural arrangement and energy dispersive X-ray spectroscopy (EDS) verified the existence of elemental aluminium which revealed maximum peaks of Al-O. The synthesized metal oxide nanoparticles (Al2O3 NPs) were evaluated for antibacterial and antifungal actvitties and the results show that they were potent against gram-positive Staphylococcus aureus; and Candida albicans and Trichophyton rubrum. The chry. A Al2O3 NP was found to displayed higher activities of antibacterial against Staphylococcus aureus (gram-positive) than Alm Al2O3 NP and Lam Al2O3 NP. The antibacterial activities of Chry.A Al2O3 NP and Alm Al2O3 NP also showed maximum zone of inhibition with minimum inhibitory concentration MIC of 0.125 and 0.250 mg/mL respectively, which higher than ciprofloxacin with 0.625 mg/mL MIC. Antifungal potential investigated revealed MIC of 3.15, 6.25 and 12.5 mg/mL for Chry.A Al2O3 NP, Alm Al2O3 NP and Lam Al2O3 NPs against Candida albicans and Trichophyton rubrum. Therefore the use of novel extracts for the synthesis of Al2O3 NPs has demonstrated good antimicrobial activities when compared to the control standard.

Experimental and density functional theory studies on some metal oxides and the derived nanoclusters: a comparative effects on human ferritin

A comprehensive investigation into the green synthesis of metal oxide nanoparticles (NPs) has garnered significant attention due to its commendable reliability, sustainability, and environmentally friendly attributes. Green synthesis methods play a crucial role in mitigating the adverse effects associated with conventional approaches employed for nanostructure preparation. This research endeavors to examine the impact of ginger plant extract-assisted green synthesis of metal oxides NPs on the serum ferritin levels of anemic diabetic patients in vitro, focusing specifically on α-Fe2O3 and ZnO NPs. Sixty diabetic volunteers with anemia (35–50 years) and thirty healthy volunteers were enrolled as controls. The assessment was conducted using the VIDAS Ferritin (FER) assay. Photoluminescence (PL) spectroscopy measurements were performed to elucidate the intrinsic and extrinsic transitions of these NPs, affirming the successful formation of α-structured iron oxide. Density functional theory (DFT) calculations were carried out at the B3LYP/6-311++G(d,2p) level of theory to investigate the geometry optimization and molecular electrostatic potential maps of the NPs. Furthermore, TD-DFT calculations were employed to explore their frontier molecular orbitals and various quantum chemical parameters. The binding affinity and interaction types of ZnO and α-Fe2O3 NPs to the active site of the human H-Chain Ferritin (PDB ID: 2FHA) target were determined with the help of molecular docking. Results unveiled the crystalline structure of ZnO and the α-structure of α-Fe2O3. Analysis of the frontier molecular orbitals and dipole moment values demonstrated that ZnO (total dipole moment (D) = 5.80 µ) exhibited superior chemical reactivity, biological activity, and stronger molecular interactions with diverse force fields compared to α-Fe2O3 (D = 2.65 µ). Molecular docking of the metal oxides NPs with human H-chain ferritin provided evidence of robust hydrogen bond interactions and metal-acceptor bonds between the metal oxides and the target protein. This finding could have a great impact on using metal oxides NPs-ferritin as a therapeutic protein, however, further studies on their toxicity are required.Graphical abstract

Aloe vera extract-assisted sol-gel synthesis of NiOx nanopyramids for supercapacitor application

Green synthesis of metal oxide nanoparticles is a cost-effective and sustainable approach that allows tailoring of the size and shape of the nanostructures for versatile applications. In this study, aloe vera extract-assisted sol-gel synthesis of nickel oxide nanoparticles (NiOx NPs) was explored for supercapacitor application. The NiOx NPs were synthesized at different aloe vera concentrations (2.5 and 5 wt%) and calcination temperatures (300, 400 and 500 °C). The phytochemical-assisted synthesis yielded NiOx nanopyramids with pores on their surface which widens as calcination temperature increases. As confirmed by XRD analysis, NiOx crystallite size also increased at higher calcination temperatures. Upon electrochemical characterization, NiOx-400B which was synthesized with 5 wt% aloe vera extract at 400 °C recorded the highest specific capacitance of 721 F g−1 at 1 A g-1 current density with the energy and power density of 10.38 Whkg−1 and 241.08 W kg-1 respectively. The charge storage mechanisms in the samples were gauged using Dunn's method which revealed that NiOx synthesized at higher calcination temperatures exhibited a greater contribution of the diffusion-controlled process. The optimized composition, NiOx-400B, also demonstrated excellent cycle stability by retaining up to 90.4 % of its original capacitance over 1500 cycles. This work is an attempt to investigate the viability of green synthesized nanoparticles in energy storage applications and the novel NiOx nanopyramid substantiates its prospect as a good electrode material for supercapacitors.

Property Tuning through Fine Size Control and Hierarchical Nanostructuring of Metal Oxide Nanoparticles Supported in Porous Matrices: a Review

In the nanoscale, matter presents different properties compared to its bulk counterparts, owing to the considerable increase of the surface/bulk ratio, as well as the occurrence of quantum confinement effects. One method to fine control the growth of nanoparticles, their size and nanostructure is to use metalorganic deposition combined with a porous matrix as host, where pores act as nanoreactors for nanoparticle growth, resulting in chemically integrated systems. In this review, we look at the history and achievements of the chemical method of impregnation-decomposition cycles for the precise size control, property tuning and tailored synthesis of metal oxide nanoparticles. We give an overview of the various oxide nanoparticles and nanomaterials developed over the years, and how the method of impregnation-decomposition cycles allowed the synthesis of pure, doped and core-shell oxide nanoparticles, as well as the tuning of their properties through the combined fine control of nanoparticle size, nanostructure, and composition.