Showing 110 results for Nano
Richa Singh,
Volume 21, Issue 1 (3-2024)
Abstract
Drug-resistance among bacteria is a concerning issue in medical field. Silver nanoparticles (AgNPs) are one of the promising novel nano-antibiotics. In the present study, AgNPs were synthesized using cell-free extract of Acinetobacter sp. challenged with silver nitrate. Preliminary observations done using UV-Vis spectrophotometry at 420 nm. Complete reduction of silver ions to AgNPs was confirmed through cyclic voltammetry. Electron microscopy revealed formation of spherical shaped nanoparticles of size upto 20 nm. These AgNPs were furthr used to determine their effect on activity of various antibiotics against pathogenic bacteria such as Neisseria and Xanthomonas. Higher antibacterial activity of AgNPs was observed against Gram-negative bacteria. Enhanced antibacterial action of AgNPs was observed with selected beta-lactam antibiotics producing upto 3-fold increase in area of zone of inhibition. On exposure to AgNPs, the minimum inhibitory concentration and minimum bactericidal concentration of antibiotics were lowered by upto 2000 times indicating potential synergistic action of AgNPs. This study clearly signifies that the drug, proved to be inefficient due to bacterial resistance, could be made functional again in presence of AgNPs. This will help in development of novel antibacterial formulations containing antibiotics and nanoparticles to combat multiple drug-resistance in microorganisms.
Sandesh Jirage, Kishor Gaikwad, Prakash Chavan, Sadashiv Kamble,
Volume 21, Issue 1 (3-2024)
Abstract
The Cu2ZnSnS4 (CZTS) thin film is newly emerging semiconductor material in thin film solar cell industry. The CZTS composed of economical, common earth abundant elements. It has advantageous properties like high absorption coefficient and best band gap. Here we have applied low cost chemical bath deposition technique for synthesis of CZTS at low temperature, acidic medium and it’s characterization. The films were characterized by different techaniques like X-Ray diffraction, Raman, SEM, Optical absorbance, electrical conductivity and PEC study. The X-Ray diffraction, Raman scattering techniques utilized for structural study. The XRD revels kasterite phase and nanocrystalline nature of CZTS thin films. These results and its purity confirmed further by advanced Raman spectroscopy with 335 cm-1 major peak. The crystallite size which was found to be 50.19 nm. The optical absorbance study carried by use of UV-Visible spectroscopy analyses its band gap near about 1.5 eV and its direct type of absorption. The electrical conductivity technique gives p-type of conductivity. The scanning electron microscopy (SEM) study finds it’s rock like unique morphology. The EDS technique confirms its elemental composition and it’s fair stoichiometry. The analysis of PEC data revealed power conversion efficiency-PCE to 0.90%.
The Cu2ZnSnS4 (CZTS) thin film is newly emerging semiconductor material in thin film solar cell industry. The CZTS composed of economical, common earth abundant elements. It has advantageous properties like high absorption coefficient and best band gap. Here we have applied low cost chemical bath deposition technique for synthesis of CZTS at low temperature, acidic medium and it’s characterization. The films were characterized by different techaniques like X-Ray diffraction, Raman, SEM, Optical absorbance, electrical conductivity and PEC study. The X-Ray diffraction, Raman scattering techniques utilized for structural study. The XRD revels kasterite phase and nanocrystalline nature of CZTS thin films. These results and its purity confirmed further by advanced Raman spectroscopy with 335 cm-1 major peak. The crystallite size which was found to be 50.19 nm. The optical absorbance study carried by use of UV-Visible spectroscopy analyses its band gap near about 1.5 eV and its direct type of absorption. The electrical conductivity technique gives p-type of conductivity. The scanning electron microscopy (SEM) study finds it’s rock like unique morphology. The EDS technique confirms its elemental composition and it’s fair stoichiometry. The analysis of PEC data revealed power conversion efficiency-PCE to 0.90%.
Amit Bandekar, Pravin Tirmali, Paresh Gaikar, Shriniwas Kulkarni, Nana Pradhan,
Volume 21, Issue 1 (3-2024)
Abstract
The Mn-Zn ferrite with a composition of Mn0.25Mg0.08Cu0.25Zn0.42Fe2O4 has been synthesized in this study using the chemical sol-gel technique at a pH of 7. The sample was prepared and subsequently annealed at a temperature of 700°C. The nanocrystalline ferrite samples were subjected to characterization using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Thermogravimetry (TG), and Differential thermal analysis (DTA). The findings of these observations are delineated and deliberated. The sample's phase composition was verified using X-ray diffraction examination. The crystalline size was determined using Scherrer's formula and was observed to be within the range of 20-75 nm. Two notable stretching bands were seen in the FTIR spectra within the range of 400-650 cm-1. The spinel structure of the produced nanoparticles was confirmed by these two bands. The magnetic characteristics of the powder were examined using a Vibrating Sample Magnetometer (VSM). The presence of M-H hysteresis loops suggests that the produced nanoparticles have superparamagnetic properties, as evidenced by their low coercive force, remanent magnetization, and saturation magnetization values.
Muhammad Shahzad Sadiq, Muhammad Imran, Abdur Rafai, Muhammad Rizwan,
Volume 21, Issue 2 (6-2024)
Abstract
With increasing energy demand and depletion of fossil fuel resources, it is pertinent to explore the renewable and eco-friendly energy resource to meet global energy demand. Recently, perovskite solar cells (PSCs) have emerged as plausible candidates in the field of photovoltaics and considered as potential contender of silicon solar cells in the photovoltaic market owing to their superior optoelectronic properties, low-cost and high absorption coefficients. Despite intensive research, PSCs still suffer from efficiency, stability, and reproducibility issues. To address the concern, the charge transport material (CTM) particularly the electron transport materials (ETM) can play significant role in the development of efficient and stable perovskite devices. In the proposed research, we synthesized GO-Ag-TiO2 ternary nanocomposite by facile hydrothermal approach as a potential electron transport layer (ETL) in a regular planar configuration-based PSC. The as synthesized sample was examined for morphological, structural, and optical properties using XRD, and UV-Vis spectroscopic techniques. XRD analysis confirmed the high crystallinity of prepared sample with no peak of impurity. The optimized GO-Ag-TiO2 ETL exhibited superior PCE of 8.72% with Jsc of 14.98 mA.cm-2 ,Voc of 0.99 V, and a fill factor of 58.83%. Furthermore, the efficiency enhancement in comparison with reference device is observed which confirms the potential role of doped materials in enhancing photovoltaic performance by facilitating efficient charge transport and reduced recombination. Our research suggests a facile route to synthesize a low-cost ETM beneficial for the commercialization of future perovskite devices.
Seyed Farzad Dehghaniyan, Shahriar Sharafi,
Volume 21, Issue 2 (6-2024)
Abstract
Mechanical alloying was employed to synthesize a nanostructured alloy with the chemical formula of (Fe80Ni20)1-xCrx (x= 0, 4). The microstructural and magnetic properties of the samples were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and a vibrating sample magnetometer (VSM). Additionally, theoretical calculations were performed using density functional theory (DFT) under the generalized gradient approximation (GGA). Simulations have demonstrated that an appropriate quantity of chromium (Cr) can dissolve within the BCC-Fe (Ni) structure, resulting in a favorable enhancement of the magnetic moment of the lattice. The XRD results indicated that after 96 hours of milling, Fe (Ni) and Fe (Ni, Cr) with a body-centered cubic (BCC) structure were formed. With increasing milling time, the grain size decreased while the microstrain increased. The saturation magnetization (Ms) of Fe80Ni20 composition increased up to 32 hours of milling, but further milling (up to 96 h) resulted in a decrease in the saturation magnetization However, for the (Fe80Ni20)96Cr4 powders, milling up to 64 h caused a reduction in Ms. The coercivity (Hc) trend was different and increased with longer milling times (up to 96 h) for both compositions.
Farah Zulkifli,
Volume 21, Issue 2 (6-2024)
Abstract
Researchers are increasingly focusing on green synthesis methods for silver nanoparticles due to their cost-effectiveness and reduced environmental impact. In this study, we utilized an edible bird's nest (EBN), a valuable economic resource, as the primary material for synthesizing silver nanoparticles using only water as the solvent. Metabolite profiling of the EBN extract was conducted using LC-QTOF-MS in positive mode (ESI+), revealing the presence of lipids, glycosides, peptides, polysaccharides, and disaccharides. Upon the addition of silver nitrate to the aqueous EBN extract, noticeable color changes from transparent to brown indicated the successful formation of AgNPs. Subsequent characterization of these silver nanoparticles involved UV-Visible spectroscopy, which revealed an absorption peak at 421 nm. Further characterization was carried out using FESEM, ATR-FTIR spectroscopy, and EDX analysis. The involvement of phenolic agents, proteins, and amino acids in reducing the silver particles was confirmed. The synthesized nanoparticles exhibited a spherical shape, and a particle size ranging from 10 to 20 nm. The presence of elemental silver was confirmed by a strong, intense peak around 3 keV in the EDX spectrum. To assess their potential, the antibacterial properties of the silver nanoparticles against Escherichia coli and Staphylococcus aureus were evaluated using the agar diffusion method.
Satish Ahire, Ashwini Bachhav, Bapu Jagdale, Thansing Pawar, Prashant Koli, Dnyaneshwar Sanap, Arun Patil,
Volume 21, Issue 2 (6-2024)
Abstract
Hybrid photocatalysts, comprising both inorganic and organic polymeric components, are the most promising photocatalysts for the degradation of organic contaminants. The nanocomposite, Titania-Polyaniline (TiO2-PANI) was synthesized using the chemical oxidative polymerization method. Various characterization techniques were employed to assess the properties of the catalysts. The ultraviolet diffuse reflectance spectroscopy (UV-DRS) analysis revealed that the TiO2 absorbs only UV light while the TiO2-PANI nanocomposite absorbs light from both UV and visible regions. The X-ray diffraction (XRD) results confirmed the presence of TiO2 (anatase) in both TiO2 nanoparticles and TiO2-PANI (Titania-Polyaniline) nanocomposite. The phases of the catalysts were verified through Raman, TEM, and SAED techniques where all results are in good agreement with each other. The average crystallite size of TiO2 nanoparticle and TiO2-PANI nanocomposite were 13.87 and 10.76 nm. The thermal stability of the catalysts was assessed by the Thermal gravimetric analysis (TGA) technique. The order of the thermal stability is TiO2 > TiO2-PANI > PANI. The crystal lattice characteristics were confirmed using Transmission electron microscopy (TEM). The surface area measurements were confirmed from the Brunauer-Emmett-Teller (BET) study and were employed for the evaluation of the photocatalytic efficiency of both, TiO2 nanoparticles and TiO2-PANI nanocomposite catalysts. The energy dispersive spectroscopy (EDS) study was employed for elemental detection of the fabricated materials. While Raman spectroscopy was employed for the chemical structure and the phase characteristics of the materials. The standard conditions for the degradation of the CF dye were 8 g/L of catalyst dosage, 20 mg/L of dye concentration, and a pH of 7. The TiO2-PANI nanocomposite exhibited superior efficiency as compared to pure TiO2 nanoparticles, achieving almost 100 % degradation in just 40 minutes.
Wed Abed,
Volume 21, Issue 2 (6-2024)
Abstract
Muddukrishnaiah Kotakonda, Sajisha V.s, Aiswarya G, Safeela Nasrin Pakkiyan, Najamol A Alungal, Mayoora Kiliyankandi K, Divya Thekke Kareth, Naheeda Ashraf Verali Parambil, Saranya Sasi Mohan, Renjini Anil Sheeba, Sarika Puthiya Veettil, Dhanish Joseph, Nishad Kakkattummal, Afsal Bin Haleem Mp, Safeera Mayyeri, Thasneem Chemban Koyilott, Nasiya Nalakath, Samuel Thavamani B, Famila Rani J, Aruna Periyasamy, Chellappa V Rajesh, Rameswari Shanmugam, Marimuthu Poornima, Tina Raju, Roshni E R, Sirajudheen Mukriyan Kallungal, Lekshmi Ms Panicker, Saranya K G, Shilpa V P,
Volume 21, Issue 3 (9-2024)
Abstract
Biogenic synthesis of papain-conjugated copper metallic Nanoparticles and their antibacterial and antifungal activities Papain metallic conjugated nanoparticles (Papain-CuNPs) were synthesised using Papain and CuSO4.5H2O. Papain-CuNPs were characterized using UV-visible spectroscopy, FT-IR, HR-TEM, XRD, FE-SEM, zeta potential, and a zeta sizer. The antibacterial activity of papain-CuNPs against human infectious microorganisms (Citrobacter spp, Pseudomonas aeruginosa and Candida albicans) was investigated. The mechanism of action of papain-CuNPs was evaluated using FE-SEM and HRTM. UV spectroscopy confirmed the plasma resonance (SPR) at 679 nm, which indicated the formation of papain-CuNPs. The FT-IR spectrum absorbance peaks at 3927, 3865, 3842, 3363, 2978, and 2900 cm-1 indicate the presence of O-H and N-H of the secondary amine, and peaks at 1643 and 1572 cm-1 represent C=O functional groups in Papain-CuNPs. EDAX analysis confirmed the presence of copper in the papain-CuNPs. The zeta potential (-42.6 mV) and zeta size (99.66 d. nm) confirmed the stability and size of the nanoparticles. XRD confirmed the crystalline nature of the papain-CuNPs. FE-SEM and HRTM showed an oval structure, and the nano particles' 16.71244–34.84793 nm. The synthesized papain-NPs showed significant antibacterial activity against clinical P. aeruginosa (15 mm). MIC 125 µg/ml) showed bactericidal activity against P. aeruginosa and the mechanism of action of Papain-NPs was confirmed using an electron microscope by observing cell damage and cell shrinking. Papain-CuNPs have significant antibacterial activity and are thus used in the treatment of P. aeruginosa infections
Mahnaz Dashti, Saeid Baghshahi, Arman Sedghi, Hoda Nourmohammadi,
Volume 21, Issue 3 (9-2024)
Abstract
Abstract
The power line insulators are permanently exposed to various environmental pollutants such as dust and fine particles. This may lead to flashovers and therefore widespread power blackouts and heavy economic damage. One way to overcome this problem is to make the insulator surface superhydrophobic. In this research, the superhydrophobic properties of the insulators were improved by applying room-temperature cured composite coatings consisting of epoxy and hydrophobic nano-silica particles. Either octadecyl trichlorosilane (ODTS) or hexamethyldisilazane (HMDS) was used to coat the silica nanoparticles and make them hydrophobic. Then, the hydrophobic silica was added to a mixture of epoxy resin and hardener. The suspension was applied on the surfaces of a commercial porcelain insulator and cold cured at ambient temperature. The coating increased the water contact angle from 50° to 149°. Even after 244 h exposure to the UV light, the samples preserved their hydrophobic properties. The adhesion of the coating was rated as 4B according to the ASTM D3359 standard. The coating decreased the leakage current by 40% and increased the breakdown voltage by 86% compared to the uncoated sample and showed promise for making power line insulators self-cleaning.
