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Nigella sativa seed based nanocomposite-MnO2/BC: An antibacterial material for photocatalytic degradation, and adsorptive removal of dye from water
摘要： Antimicrobial Nigella sativa seed-based nanocomposite, MnO2/BC, was synthesized and utilized for water purification through adsorption and photocatalytic degradation. MnO2/BC was prepared by co-precipitation method, and characterized using FT-IR, XRD, SEM, TEM, TGA, and DSC techniques. The composite was investigated for inhibition of bacterial cells growth. FT-IR spectrum indicated the presence of oxygenous groups on the surface; TGA and DSC showed thermal degradation; and XRD, SEM, and TEM investigations indicated amorphous, and porous nature of MnO2/BC having particle size of 190-220 nm. The nanocomposite inhibited the growth of both Gram-positive and Gram-negative bacteria cells in water. The adsorption of Methylene blue (MB) from water was investigated in batch method in terms of amount of MnO2/BC, MB concentration, pH, time, and temperature. 1.0 gL-1 of MnO2/BC removed more than 98% of MB from aqueous solution having concentration of 10 mgL-1 and pH 7.0 at 27°C. The maximum Langmuir adsorption capacity of MnO2/BC was 185.185 mgg-1 at 45°C. The adsorption was an endothermic process which obeyed Freundlich isotherm, and pseudo-second order kinetics. Therefore, the MB binding onto MnO2/BC surface was site-specific partially through weak hydrogen bonding and electrostatic interactions. The photocatalytic activity of MnO2/BC has been investigated by degrading the MB molecules/ions in water under the sunlight and 85% of degradation was achieved during 120 min irradiation. The dye was desorbed at lower pH and regenerated MnO2/BC was used for second cycle of MB adsorption. The results obtained for this study are much better than the previous MB adsorption studies with acid washed Black cumin seeds and MnFe2O4/BC for which the capacities were 73.529 mgg-1 and 10.070 mgg-1 at 27°C, respectively (J. Mol. liq. 2018a, 264, 275-284; J. Clean. Prod. 2018a, 200, 996-1008).
关键词： MnO2/BC,Antibacterial activity,Photocatalytic degradation,Adsorption,Nigella sativa plant seeds,Methylene blue
更新于2025-09-10 09:29:36
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Synthesis, characterization and comparative studies of dual doped ZnO nanoparticles for photocatalytic applications
摘要： Pure and dual doped ZnO nanoparticles were synthesized via the wet chemical method. The synthesized samples were characterized by XRD, HR-SEM/EDS, HR-TEM, UV–Vis, PL, FT-IR, and FT-Raman spectral measurements. The prepared ZnO nanoparticles exhibit a hexagonal wurtzite structure and [Ce–La, La–Gd, Gd–Ce] rare earth dual doped ZnO nanoparticles was confirmed from the shift in XRD peaks position, cell parameter and also changes in the peaks intensity. HR-SEM/EDS and HR-TEM show spherical in shape with less agglomeration on the surface of all samples and the images are clearly revealed that the particle size ~ 40 nm (PZ), 14 nm (ZCL3), 16 nm (ZLG3) and 28 nm (ZGC3). UV–Vis spectra show a strong Ultraviolet region absorbance for ZCL3 sample with the low Energy band gap value of 2.81 eV. The presences of the functional group and molecular vibrations are characterized by employing the FT-IR and FT-Raman spectra. From the PL spectra, it was found that the peak position of all samples produces a visible emission. The photocatalytic performance of the synthesized doped nanoparticles found to exhibit better degradation of MB dye under solar irradiation ZCL3 showed an increase in the photo catalytic decolorization efficiency. The bactericidal activity of dual doped ZnO nanoparticles was investigated against Gram-positive and Gram-negative bacteria and compare with standard ampicillin. We observe that ZCL3 sample have excellent antibacterial activity against Gram-negative bacteria (P. mirabilis) and the mean zone of inhibition ~ 20 mm.
关键词： photocatalytic applications,ZnO nanoparticles,dual doping,antibacterial activity
更新于2025-09-10 09:29:36
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Biological interactions of biocompatible and water-dispersed MoS2 nanosheets with bacteria and human cells
摘要： Two dimensional materials beyond graphene such as MoS2 and WS2 are novel and interesting class of materials whose unique physico-chemical properties can be exploited in applications ranging from leading edge nanoelectronics to the frontiers between biomedicine and biotechnology. To unravel the potential of TMD crystals in biomedicine, control over their production through green and scalable routes in biocompatible solvents is critically important. Furthermore, considering multiple applications of eco-friendly 2D dispersions and their potential impact onto live matter, their toxicity and antimicrobial activity still remain an open issue. Herein, we focus on the current demands of 2D TMDs and produce high-quality, few-layered and defect-free MoS2 nanosheets, exfoliated and dispersed in pure water, stabilized up to three weeks. Hence, we studied the impact of this material on human cells by investigating its interactions with three cell lines: two tumoral, MCF7 (breast cancer) and U937 (leukemia), and one normal, HaCaT (epithelium). We observed novel and intriguing results, exhibiting evident cytotoxic effect induced in the tumor cell lines, absent in the normal cells in the tested conditions. The antibacterial action of MoS2 nanosheets is then investigated against a very dangerous gram negative bacterium, such as two types of Salmonellas: ATCC 14028 and wild-type Salmonella typhimurium. Additionally, concentration and layer-dependent modulation of cytotoxic effect is found both on human cells and Salmonellas.
关键词： antibacterial activity,biocompatibility,MoS2 nanosheets,two-dimensional materials,cytotoxicity
更新于2025-09-10 09:29:36
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Structure, photocatalytic and antibacterial activity study of Meso porous Ni and S co-doped TiO2 nano material under visible light irradiation
摘要： Undoped and Ni-S co-doped Mesoporous TiO2 nano materials were synthesized by using sol-gel method. The characteristic features of as prepared catalyst samples were investigated using various advanced spectroscopic and analytical techniques. The characterization results of the samples revelled that all the samples exhibited anatase phase (XRD), decreasing band gap (2.68 eV) (UV-Vis-DRS), small particle size (9.2 nm) (TEM), High surface area (142.156 m2/g) (BET), particles with spherical shape and smooth morphology (SEM), there is a frequency shift observed for co-doped sample (FT-IR) and the elemental composition electronic states and position of the doped elements (Ni and S) in the TiO2 lattice analyzed by XPS and EDX. These results supported the photocatalytic degradation of Bismarck Brown Red (BBR) achieved with in 110 min and also exhibited the antibacterial activity on Staphylococcus aureus (MTCC-3160), Pseudomonas fluorescence (MTCC-1688) under visible light irradiation.
关键词： Sol-gel,photocatalysis under visible light,Antibacterial Activity,Ni-S co-doped TiO2,degradation of Bismarck Brown Red
更新于2025-09-10 09:29:36
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Rose Bengal Incorporated to α-Cyclodextrin Microparticles for Photodynamic Therapy against the cariogenic microorganism Streptococcus mutans
摘要： Rose Bengal@α-cyclodextrin (RB@α-CD) microparticles (μPs) were prepared and the RB inclusion in α-CD was experimentally demonstrated through infrared, UV-VIS absorption spectroscopy and cyclic voltammetry. The RB inclusion in α-CD was theoretically investigated using classical molecular mechanics calculations, the simulation results showing that RB can be included in both the narrow and wide apertures of the α-cyclodextrin ring with configurations exhibiting average binding energies of about 27 kcal.mol-1. The prepared RB@α-CD microparticles were characterized through Scanning Electron Microscopy (SEM) and it was demonstrated that they are highly efficient in the photodynamic therapy against a Streptococcus mutans (the main bacteria of cariogenic dental plaque) suspension, as a concentration of RB@α-CD μPs 10 times smaller than the usual concentration of pure RB is still capable to produce significant antibacterial activity.
关键词： antibacterial activity,molecular interaction simulations,Rose Bengal,photodynamic therapy,α-cyclodextrin microparticles
更新于2025-09-10 09:29:36
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Microwave-assisted synthesis, photocatalysis and antibacterial activity of Ag nanoparticles supported on ZnO flowers
摘要： ZnO flowers with different Ag contents were successfully synthesized by a simple microwave method. Phase and morphologies of heterostructure Ag/ZnO composites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The results showed that heterostructure Ag/ZnO composites were composed of face centered cubic Ag supported on hexagonal ZnO flowers of hexagonal prism nanorods with 100 nm wide and about 2–3 μm long, including the detection of Ag 3d5/2 and Ag 3d3/2 for metallic Ag of 10 wt% Ag/ZnO composites. The photocatalytic activity of heterostructure Ag/ZnO composites was evaluated through photodegradation of methylene blue under UV light. Escherichia coli DH5α (gram-negative bacteria) and Stapphylococcus aureus ATCC 25923 (gram-positive bacteria) were used to test for antibacterial activity. The 10 wt% Ag/ZnO composites showed the best performance for photocatalysis and had the antibacterial activity.
关键词： Antibacterial activity,Photocatalysis,Ag/ZnO composites
更新于2025-09-10 09:29:36
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Antibacterial and photocatalytic activity of anatase phase Ag-doped TiO2 nanoparticles
摘要： A simple and new solid-state molten-salt method to synthesise silver (Ag)-doped titanium dioxide (TiO2) nanoparticles for solar light-induced photocatalytic applications is examined. Ag-doped TiO2 nanoparticles with varied Ag content ranging from 3 to 10% were synthesised by a single-step molten-salt synthesis method. The effect of Ag content on the antibacterial and photocatalytic activity of nanoparticles was tested. The prepared nanoparticles were studied by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, ultraviolet–visible (UV–vis) diffusive re?ectance spectrometer (UV–vis DRS) and powder X-ray diffraction. The SEM image of nanoparticles clearly showed the presence of agglomerated spherical particles. The EDX analysis of the particles con?rmed successful doping of particles in the presence of the Ag in the particles. The doping of Ag in TiO2 produced TiO2 pure anatase phase. According to UV–vis DRS results, increasing Ag-doped content in the Ag-doped TiO2 resulted in a higher visible absorption capability of the materials. Ag doping also improved the antibacterial and photocatalytic activity of TiO2 nanoparticles. The maximum photocatalytic activity under light irradiation was observed for 5% Ag-doped TiO2.
关键词： antibacterial activity,anatase phase,photocatalytic activity,molten-salt method,Ag-doped TiO2
更新于2025-09-09 09:28:46
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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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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