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Enhanced Antibacterial Activity and Photo-Catalytic Properties of ZnO Nanoparticles: <i>Pedalium Murex</i> Plant Extract-Assisted Synthesis
摘要： Semiconductor ZnO samples with two different morphologies such as nanoparticles (ZnO-NPs) and nano-sheets (ZnO-NSs) was successfully prepared by microwave heating (MHM) and modified sol–gel (SGM) method, respectively using Pedalium Murex plant extract as the bio-reducing agent. Structural, purity and morphology of the samples was examined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. Optical property analysis and band gap calculation were carried out by UV-Visible diffuse reflectance (DRS) and photoluminescence (PL) spectroscopy techniques. Kubelka-Munk method was used to measure band band gap of the samples and it shows 3.42 eV and 3.23 eV for ZnO-NPs and ZnO-NSs, respectively. The antibacterial activities of ZnO-NPs and ZnO-NSs against both gram positive (Bacillus subtilis, Staphylococcus aureus) as well as gram negative bacteria (Proteus mirabilis, Salmonella typhi) were tested by modified disc diffusion method and showed important antibacterial activity against P. mirabilis and S. typhi. The photocatalytic activity of ZnO nano-catalysts (ZnO-NPs and ZnO-NSs) for the degradation of methylene blue (MB) dye was studied under solar lighting and the results showed that the samples ZnO-NPs with smaller particle size considerable degradation of MB than ZnO-NSs.
关键词： Nanoparticles,Photo-Catalytic Applications,Pedalium Murex Plant,Antibacterial Activity,ZnO,Optical Properties
更新于2025-09-09 09:28:46
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Photocatalytic and Antibacterial Activities of Silver and Iron Doped Titania Nanoparticles in Solution and Polyaspartic Coatings
摘要： Visible region active photocatalytic coatings are of interest for antimicrobial activity in low light applications or those employing LED lights with limited UV content. This work examined Ag and Fe doped titania nanoparticles (nTiO2) with varying dopant ranges in polyaspartic polymer coatings for potential light and dark activity. First, the Ag and Fe doped nTiO2 were synthesized by sol-gel chemistry with varying dopant concentrations, then characterized with respect to their size and aggregate size distribution, crystallinity, and surface and band gap features. The photocatalytic activity was then tested with methylene blue (MB) under both AM1.5G and visible light. From both sample sets (Ag and Fe doped nTiO2), the best photo catalytically active sample materials were chosen for antibacterial tests with gram negative Escherichia coli (E. coli) and gram positive Bacillus subtilis (B. subtilis) in (a) solution and (b) polyaspartic nanocomposites under UV and visible irradiation. The results showed that Ag doped nTiO2 samples delivered the best photocatalytic activity and excellent antibacterial action, even in the dark, attributed to both an enhanced band gap and surface area, as well as a combination of photocatalytic activity and Ag being present at the nanoparticle’s (NP) surface. No leaching of Ag at room temperature was observed from the nTiO2 structure, giving potential for next generation coatings that are both light and dark active.
关键词： Fe doping,polyaspartic composites,antibacterial activity,photo-catalysis,Ag doping,nanoparticles,Titania
更新于2025-09-09 09:28:46
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Alternative Green Chemistry Methods of Silver Nanoparticles Synthesis: Review and Comparison
摘要： Green chemistry is a branch of chemistry that deals with natural materials such as plants, fungi, bacteria, algae, and rocks rather than chemical components. Advantages of green chemistry rather than chemical are that no toxic components are released, inexpensive, available anytime, easy to get, and eco-friendly. Metallic nanoparticles have received great attention from chemists, physicists, biologists and engineers who wish to use them for the development of a new generation of nanodevices. One of the important metal nanoparticles is the silver nanoparticles (AgNPs). Silver is a nontoxic agent having an antibacterial, antifungal, and antioxidant properties. AgNPs have been used in many applications such as catalysis, biotechnology, biomedical applications, electronics, and in the treatment of burns and wounds. The green synthesis of AgNPs involves three main steps: the selection of the solvent medium, the selection of environmentally reducing agents, and the selection of non-toxic substances for the stability of AgNPs. In this review, we will discuss some green chemistry methods to synthesize AgNPs via plant extracts and other natural agents, such as fungi, bacteria, and algae. In addition, we will compare between these methods, according to their applications and stabilities.
关键词： Green Chemistry,Antibacterial Activity,Extract,AgNPs,Synthesis
更新于2025-09-04 15:30:14
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Green Synthesis of Co <sub/>3</sub> O <sub/>4</sub> Nanorods for Highly Efficient Catalytic, Photocatalytic, and Antibacterial Activities
摘要： Cobalt oxide nanorods were successfully synthesized by a hot plate combustion method using the plant extract of Vitis vinifera. The plant extract as an alternative to toxic chemicals can be used generally as reducing and capping agents. The obtained nanorods were characterized by XRD, FT-IR, Raman, TEM, SAED, EDX, DRS, PL and VSM techniques for the structural, morphological, optical and magnetic properties. The XRD, FT-IR, Raman, EDX analysis confirmed the high purity of the sample. The TEM and SAED results showed the rod shape morphology of the sample. DRS and PL showed the band gap energy and emission at visible region. VSM showed the antiferromagnetic nature of the sample. The photocatalytic activities of the as-prepared cobalt oxide nanorods were investigated for the degradation of textile dying waste water. As per the standards of Indian pollution control board for industrial waste water let out into river bodies, the degradation reactions of waste water was found to be 250 mg/L at 150 min. Also, the same catalyst is used for the reduction of 4-nitrophenol and 4-nitroaniline using sodium borohydride as a reducing agent and it exhibits excellent reduction reaction, because of the high active surface sites. The time taken for the reduction reaction was 300 sec and 210 sec for 4-nitrophenol and 4-nitroaniline respectively. Also, the antibacterial activities towards the bacterial strains were studied and reported.
关键词： Cobalt Oxide,Antiferromagnetic,Antibacterial Studies,Catalytic Reduction,Vitis vinifera Plant Extract,Photocatalytic Degradation
更新于2025-09-04 15:30:14
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Synthesis and characterization of SiO2 doped Fe2O3 nanoparticles: Photocatalytic and antimicrobial activity evaluation
摘要： Silica doped iron oxide (SiO2 doped Fe2O3) nanoparticles (NPs) were successfully synthesized by co-precipitation method at 70 °C using different solvents (acetonitrile, n-hexane and isoamyl alcohol). The synthesized NPs were characterized by FT-IR, X-Ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermal gravimetric analysis-differential scanning calorimetry (TGA-DSC) and dynamic light scattering (DLS) techniques. The size of SiO2 doped Fe2O3 NPs was in the range of 5.89 nm–19.89 nm and ellipsoidal morphology with tendency of aggregate formation due to dipole-dipole interactions. The solvents showed variable effect on physico-chemical properties of the NPs. As-synthesized NPs were also evaluated for the antimicrobial activity against set of bacterial and fungal strains i.e., Candida parapsilosis, Aspergilus niger, Bacillus subtilis and Escherichia coli. It was observed that solvents also affected the NPs antimicrobial activity. The SiO2 doped Fe2O3 NPs prepared in acetonitrile showed highest antibacterial as well as antifungal activity. The MIC values were recorded to be 0.31 mg/L and 0.21 mg/L (acetonitrile) and 0.24 mg/L and 0.18 mg/L (isoamyl alcohol) for C. parapsilosis and A. niger, respectively. NPs prepared in n-hexane showed the MIC value of 0.09 mg/L. The photo-caalytic activity (PCA) was evaluated by degrading Rhodamine B (RhB) dye. The RhB degradation was 83% for Fe2O3 NPs, which was enhanced considerably in case of doping, solvents also showed variable effect on the PCA for RhB dye degradation. Results revealed that the SiO2 doped Fe2O3 NPs are ef?cient anti-microbial agent as well as highly active photocatalysts and could possibly be used for the degradation of dyes in textile wastewater.
关键词： Antibacterial activity,Physico-chemical properties,Photocatalytic activity,Doping,Nanoparticle,Solvents effect
更新于2025-09-04 15:30:14
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Facile Synthesis of Ag/ZnO Photocatalysts on the Degradation of Diuron Herbicide Under Simulated Solar Light and the Investigation of Its Antibacterial Activity for Waste-Water Treatment
摘要： Nanocrystalline Ag/ZnO powders have been successfully prepared by a modified polyol process using triethylene-glycol (TEG) as solvent, reducing and stabilizing agent. The synthesis procedure has been conducted without any post-synthesis thermal treatment. The structural and optical properties have been characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption study, inductively coupled plasma optical emission spectroscopy and UV–Vis diffuse reflectance spectroscopy. The photocatalytic activity of Ag/ZnO materials has been studied by analyzing the degradation of an herbicide, diuron, under solar light. Ag/ZnO photocatalysts with optimized x = 0.7% Ag content showed 14 times higher rate of degradation than that of unmodified ZnO. We attribute these observations to the addition of silver nanoparticles allowing interfacial oxide-to-metal electron transfer within the hybrid Ag/ZnO photocatalyst. The inhibitory and bactericidal activities of samples have been tested against Gram-negative bacteria; Escherichia coli, Salmonella typhimurium and gram-positive bacteria; Staphylococcus aureus, Enterococcus faecium and Candida albicans. The results showed that the Ag/ZnO can be used as photocatalysts and antibacterial agents for potential practical applications in the wastewater treatment.
关键词： Nanoparticles,Photocatalysis,Antibacterial,ZnO,Wastewater treatment,Ag
更新于2025-09-04 15:30:14
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Light-Induced Assembly of Metal Nanoparticles on ZnO Enhances the Generation of Charge Carriers, Reactive Oxygen Species and Antibacterial Activity
摘要： Increasing the photocatalytic activity of semiconductors by forming heterojunctions with metal improves their energy transfer efficiency and environmental remediation capabilities. However, our knowledge regarding the structure-activity relationship of semiconductor/metal hybrid nanostructures is lacking due to poor control over their physicochemical properties. Here, we report a facile way to make ZnO/metal heteronanoparticles by mixing/irradiation process of ZnO and metal nanoparticles. The resultant products provide an expedient model to explore the effects of various metal NPs on light-induced electron/hole separation, reactive oxygen species (ROS) production and antibacterial activities of ZnO NPs. Electron spin resonance spectroscopy was used to compare the effect of mixing Pt, Au, or Ag NPs at different size and concentration with ZnO NPs on light-induced electron-hole separation and ROS production. The enhancing effect of metal NPs depends on particle size, composition, and mass ratio of the metal NPs to the ZnO NPs. Smaller-sized Pt NPs are more efficient in promoting charge carrier generation and ROS production. At 5 nm, Ag NPs promoted charge carrier generation more efficiently than Pt and Au NPs, but Pt NPs promoted ROS generation more efficiently than Au and Ag NPs. These results provide valuable strategy to design the synthesis of semiconductor/metal hybrid nanostructures and easy tailoring of ROS and charge carrier production.
关键词： reactive oxygen species,photocatalytic activity,metal nanoparticles,antibacterial activity,ZnO
更新于2025-09-04 15:30:14
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Towards understanding the enhancement of antibacterial activity in manganese doped ZnO nanoparticles
摘要： In this work we focus on enhancing the antibacterial activity of ZnO nanoparticles by Mn doping, synthesized using a wet-chemical method. The as-obtained precursor powders were deeply investigated by thermal analyses correlated with the evolved gas analysis (TG-DTA-FT-IR) and by in situ high-temperature XRD to elucidate the thermally induced processes and to understand the manganese doped ZnO nanoparticles formation. The hexagonal wurtzite-type structure and the morphological characteristics of the thermally treated samples have been investigated by X-ray diffraction, and HRTEM. An average particle size ranging between 10 to 29 nm and a polyhedral and spherical morphology with a tendency to form aggregates were evidenced by TEM images. Optical absorption measurements reveal that the band gap of ZnO decreased from 3.19 to 2.99 eV, which confirmed the existence of Zn-O-Mn interaction. The incorporation of the Mn ions into the ZnO lattice has been studied by EPR spectroscopy and also, the generation of reactive oxygen species (ROS) has been evidenced by using the EPR coupled with the spin trapping probe technique. Here, we report that in addition to altering the crystallite size, morphology and optical absorption characteristics of ZnO, the introduction of Mn dopant also improves the antibacterial efficiency against pathogenic microorganisms, namely Escherichia coli and Bacillus cereus.
关键词： Mn doping,antibacterial activity,ZnO nanoparticles,reactive oxygen species,wet-chemical synthesis
更新于2025-09-04 15:30:14
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Phyto-Mediated Photo Catalysed Green Synthesis of Silver Nanoparticles Using Durio Zibethinus Seed Extract: Antimicrobial and Cytotoxic Activity and Photocatalytic Applications
摘要： In the present study, we have developed a green approach for the synthesis of silver nanoparticles (DSAgNPs) using aqueous extract of Durio zibethinus seed and determined its antibacterial, photocatalytic and cytotoxic effects. Surface plasmon resonance confirmed the formation of DSAgNPs with a maximum absorbance (λmax) of 420 nm. SEM and TEM images revealed DSAgNPs were spherical and rod shaped, with a size range of 20 nm and 75 nm. The zeta potential was found to be ?15.41 mV. XRD and EDX analyses confirmed the nature and presence of Ag and AgCl. DSAgNPs showed considerable antibacterial activity, exhibited better cytotoxicity against brine shrimp, and shown better photocatalytic activity against methylene blue. Based on the present research work, it can be concluded that DSAgNPs could be used in the field of water treatment, pharmaceuticals, biomedicine, biosensor and nanotechnology in near future.
关键词： antibacterial,silver,Durio zibethinus seed,green synthesis,cytotoxicity,nanoparticles
更新于2025-09-04 15:30:14
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Multifunctional Flax Fibres Based on the Combined Effect of Silver and Zinc Oxide (Ag/ZnO) Nanostructures
摘要： Cellulosic fibre-based smart materials exhibiting multiple capabilities are getting tremendous attention due to their wide application areas. In this work, multifunctional flax fabrics with piezoresistive response were developed through the combined functionalization with silver (Ag) and zinc oxide (ZnO) nanoparticles (NPs). Biodegradable polyethylene glycol (PEG) was used to produce AgNPs, whereas ZnONPs were synthetized via a simple and low-cost method. Flax fabrics with and without NPs were characterized by Ground State Diffuse Reflectance (GSDR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and Thermogravimetric analysis (TGA). After creating a conductive surface by flax functionalization with AgNPs, ZnONPs were synthetized onto these fabrics. The developed fibrous systems exhibited piezoresistive response and the sensor sensitivity increased with the use of higher ZnO precursor concentrations (0.4 M). Functionalized fabrics exhibited excellent antibacterial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, higher hydrophobicity (WCA changed from 00 to >1000), UV radiation resistance, and wash durability. Overall, this work provides new insights regarding the bifunctionalization of flax fabrics with Ag/ZnO nanostructures and brings new findings about the combined effect of both NPs for the development of piezoresistive textile sensors with multifunctional properties.
关键词： piezoresistive response,smart and multifunctional materials,cellulosic fibres,silver and zinc oxide nanoparticles,antibacterial effect,hydrophobicity
更新于2025-09-04 15:30:14