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Graphite to Graphene: Green Synthesis Using Opuntia ficus-indica
摘要： Green synthesis promotes partial or total substitution of chemicals that are potentially harmful to the environment with more friendly ones and is also concerned with decreasing energy consumption. In this study, commercial graphite (1.0 g) was mixed with Opuntia ficus-indica (Ofi) (1.0 ml) and 50 ml deionized water in a glass beaker. The mixture was sonicated in an ultrasonic bath for 30 min at room temperature. Subsequently, the supernatant was transferred to a glass substrate and dried. To characterize the graphitic nanostructure, we used Raman spectroscopy, x-ray diffraction (XRD) analysis, x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Raman spectroscopy was used to characterize the crystal structure. The ratio of the relative intensity of the G and 2D peaks in the Raman spectrum followed by deconvolution of the 2D band suggested that four and five layers of graphene were formed. The XRD profile showed a strong decrease in the (002) peak intensity with a thickness of 0.34 nm characterizing the graphite structure. The C:O ratio measured by XPS showed a degree of oxidation comparable to reports on few-layer graphene (FLG), and AFM images showing the roughness of the sheets revealed small steps of 1 nm with length of about 100 nm. Structural and morphological properties were analyzed by TEM. We found thin graphene layers of about one micron in extent; at 10-nm scale, structures of two, three, four, and five layers were identified. These results suggest that this method can be used for synthesis of FLG via an environmentally friendly route without use of acids or strong chemical oxidants.
关键词： few-layer graphene,sonication,Opuntia ficus-indica,Green synthesis
更新于2025-09-19 17:15:36
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Development of <i>Lactobacillus kimchicus</i> DCY51 <sup>T</sup> -mediated gold nanoparticles for delivery of ginsenoside compound K: <i>in vitro</i> photothermal effects and apoptosis detection in cancer cells
摘要： We report a non-covalent loading of ginsenoside compound K (CK) onto our previously reported gold nanoparticles (DCY51T-AuCKNps) through one-pot biosynthesis using a probiotic Lactobacillus kimchicus DCY51T isolated from Korean kimchi. The ginsenoside-loaded gold nanoparticles were characterized by various analytical and spectroscopic techniques such as field emission transmission electron microscopy (FE-TEM), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, X-ray powder diffraction (XRD), selected area electron diffraction (SAED), Fourier-transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS). Furthermore, drug loading was also determined by liquid chromatography–mass spectrometry (LC–MS). In addition, DCY51T-AuNps and DCY51T-AuCKNps were resistant to aggregation caused by pH variation or a high ionic strength environment. Cell-based study confirmed that DCY51T-AuCKNps exhibited slightly higher cytotoxicity compared to ginsenoside CK treatment in A549 cells (human lung adenocarcinoma cell line) and HT29 (human colorectal adenocarcinoma cell line). Upon laser treatment, DCY51T-AuCKNps showed enhanced cell apoptosis in A549, HT29 and AGS cells (human stomach gastric adenocarcinoma cell line) compared with only DCY51T-AuCKNps treated cells. In conclusion, this preliminary study identified that DCY51T-AuCKNps act as a potent photothermal therapy agents with synergistic chemotherapeutic effects for the treatment of cancer.
关键词： green synthesis,gold nanoparticles,Ginsenoside CK,photoluminescence,photothermal therapy,anticancer activity,drug delivery
更新于2025-09-19 17:15:36
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Greener synthesis of zinc oxide nanoparticles using Trianthema portulacastrum extract and evaluation of its photocatalytic and biological applications
摘要： Synthesis of nanoparticles (NPs) through “green” chemistry is an exciting area of research with wide applications. Trianthema portulacastrum’s extract containing greater amount of reducing agents has been explored first time for the synthesis of ZnO-NPs that characterized with UV/Vis, XRD, FT-IR, SEM, EDX, HR-TEM and XPS. The particles of ZnO-NPs are crystalline and having the size in the range of 25-90 nm. The cell viability of ZnO-NPs was studied using Mouse pre-osteoblast cell line MC3T3-E1 sub-clone 14 cells which confirmed its biocompatibility that render for biomedical applications. The antibacterial properties were evaluated against Staphylococcus aureus and Escherichia coli which showed high potency of synthesized ZnO-NPs against these species. The antifungal activities of ZnO-NPs were screened against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus of fungal species. The antioxidant activity of the as-synthesized NPs was also studied using DPPH (2, 2-diphenyl-1-picrylhydrazyl) substrate. The ZnO-NPs were evaluated for catalytic activity through degradation of Synozol Navy Blue-KBF textile dye using solar irradiation that causes 91% degradation of the dye in 159 minutes. Mechanistic pathways for the degradation of Synozol Navy Blue-KBF dye using ZnO-NPs were also proposed from the pattern of the degradation of the dye and the resulting by-products. The results concluded that the ZnO-NPs synthesized by green method have high biological and photocatalytic applications.
关键词： green synthesis,ZnO-NPs,Dye degradation,biological Activities,crystalline structure
更新于2025-09-19 17:15:36
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Fe-TiO <sub/>2</sub> Nanoparticles Synthesized by Green Chemistry for Potential Application in Waste Water Photocatalytic Treatment
摘要： Anatase TiO2 nanoparticles doped with iron ions have been synthesized via the green chemistry method using aqueous extract of lemongrass (Cymbopogon citratus) obtained from Soxhlet extraction and doped by wet impregnation. The TiO2 anatase phase has been doped with Fe3+ (0.05, 0.075, and 0.1 Fe3+ : Ti molar ratio) at 550°C and 350°C, respectively. The scanning electron microscopy with energy-dispersive X-ray (SEM-EDS) shows nanoparticle clusters and efficiencies of impregnations between 66.5 and 58.4% depending on the theoretical dopant amount. The electron transmission microscopy (TEM) reveals final particle sizes ranging between 7 and 26 nm depending on the presence or not of the dopant. The cathodoluminescence (CL) and photoluminescence (PL) studies of the doped and undoped nanoparticles show a luminescence signal attributed to surface oxygen vacancies (visible CL emission 380–700 nm and PL emission 350–800 nm); additionally, a decrease in emission intensity is observed due the inhibition of the recombination of the photogenerated electron-holes pairs; moreover, nanopowders were analyzed by UV-Vis spectrophotometry of diffuse reflectance, and the absorption edge of the Fe-TiO2 in comparison to undoped TiO2 is extended greatly toward the visible light. The six bands (A1g + 2B1g + 3Eg) found by Raman spectroscopy and the x-ray diffraction pattern (XRD) confirm that synthesized TiO2 is only anatase phase, which is commonly used as a catalyst in waste water treatment, specifically in heterogeneous photocatalytic processes.
关键词： lemongrass extract,green synthesis,Fe-TiO2 nanoparticles,waste water,photocatalytic treatment
更新于2025-09-19 17:15:36
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Green Synthesis of Bismuth Sulfide Nanostructures with Tunable Morphologies and Robust Photoelectrochemical Performance
摘要： Manipulating the morphology of chalcogenide semiconductor crystals to tailor their shape- and size-dependent properties is much desired but remains a grand challenge. Herein, we for the first time develop a green, facile and surfactant-free hydrothermal approach for the synthesis of bismuth sulfide (Bi2S3) with highly tunable morphologies in H2WO4 aqueous solution. The H2WO4 is prone to balance the concentration of Bi3+ to S2- in aqueous solution, thus modulating the nucleation and epitaxial growth of Bi2S3. Specifically, in the presence of lower H2WO4 concentration, low number of Bi2S3 nuclei facilitates the preferred growth of nanorod structures along [001] direction, while the Bi-deficient, S-rich conditions in higher H2WO4 concentration give rise to Bi2S3 nanotubes, presumably due to the stronger interlayer interaction and preferred growth in [hk0] direction. The resulting Bi2S3 nanostructures exhibit broad absorption overlapping UV-Visible-NIR regions and red-shifted absorption edges owing to the increased S/Bi molar ratio in Bi2S3 lattices. The Bi2S3 nanorods with higher aspect ratio demonstrate an enhanced photocurrent response by virtue of the improved charge carrier mobility along [001] direction. Different from previous synthetic methodologies, this work details a facile, effective, and environmentally-benign protocol for the synthesis of Bi2S3 nanomaterials in the aqueous medium without any organic reagents. Noteworthy, the excellent and tailorable photoelectrochemical (PEC) performance endows these Bi2S3 nanostructures with vast potential in solar cell and photodetector applications.
关键词： Photoelectrochemical performance,Morphology control,Nanostructures,Green synthesis,Bismuth sulfide
更新于2025-09-19 17:15:36
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Synthesis of Microwave-Assisted Fluorescence Carbon Quantum Dots Using Roasteda??Chickpeas and its Applications for Sensitive and Selective Detection of Fe3+ Ions
摘要： A simple method for the green synthesis of fluorescent carbon quantum dots (CQDs) has been developed by using roasted chickpea as carbon source in one-step without using any chemical. Interestingly, not only the carbon source of CQDs and the whole synthesis procedure are environmentally friendly, but also the synthesized CQDs have shown many advantageous properties such as high fluorescence intensity, excellent photostability, and good water solubility. CQDs which were firstly synthesized from roasted–chickpeas by a microwave-assisted pyrolysis have been characterized using UV-vis absorption spectroscopy, fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR) spectroscopy, X-ray diffraction (XRD) technique and transmission electron microscopy (TEM). In addition, the details of the structure have been revealed by the electron diffraction (SAED; selected-area electron diffraction) method based on the TEM images. The synthesized CQDs emits blue fluorescence under UV light (at 365 nm). A microwave oven (350 watts) was used to prepare CQDs in 120 s. The effect of various metal ions on the fluorescence intensity of CQDs was investigated in order to determine its utality in the detection of metal ions. It was determined that 1.38 mg/L of Fe3+ ions quenched the fluorescence intensity of the CQDs by 65%. The linear range is observed between 11.25 and 37.50 μM with limit of detection (LOD) and limit of quantification (LOQ) of 2.74 μM and 8.22 μM, respectively. CQDs which are highly selective and sensitive for Fe3+ ions was used to determine Fe3+ ions in certified reference material (CRM-SA-C). Fe3+ ions concentration was determined with precision values of more than 95% as intra-day and inter-day relative standard deviation (RSD%) is 5 at room temperature.
关键词： Green-synthesis,Roasted–chickpea,Microwave,Fluorescence,Fe3+ detection,Carbon quantum dot
更新于2025-09-19 17:13:59
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Green-synthesized, low-cost tetracyanodiazafluorene (TCAF) as electron injection material for organic light-emitting diodes
摘要： Two electron-deficient azaacenes including di- and tetra-cyanodiazafluorene (DCAF and TCAF) with the advantages of deep lowest unoccupied molecular orbital (LUMO), green-synthesis, low-cost, simply purification method, excellent yields have been obtained, characterized and used as electron injection materials (EIMs) in three groups of electroluminescence devices. Device B with TCAF as EIM exhibited the best performance including turn-on voltage of 5.0 V, stronger maximum luminance intensity of 31,549 cd/m2, higher luminance efficiency of 62.34 cd/A and larger power efficiency of 21.74 lm/W which are 0.53, 6.7, 9.3 and 15.3 times than that of device A with DCAF as EIMs, respectively. The enhanced interfacial electron injection ability of TCAF than that of DCAF is supported by its better electron mobility in electron-only device, deeper LUMO (-4.52 eV), and stronger electronic affinity. Best external quantum efficiency of 16.56% was achieved with optimized thicknesses of TCAF as EIM and TPBi as electron transporting layer. As a new comer of acceptor family, TCAF would push forward organic electronics with more fascinating and significant applications.
关键词： Tetracyanodiazafluorene (TCAF),Organic light-emitting diode,Green-synthesis,Electron-injection material,Acceptor
更新于2025-09-19 17:13:59
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A perspective approach towards appreciable size and cost-effective solar cell fabrication by synthesizing ZnO nanoparticles from Azadirachta indica leaves extract using domestic microwave oven
摘要： A simple domestic microwave oven-assisted solvothermal method has been used successfully to synthesize spherical nanoparticles of zinc oxide (ZnO NPs) for solar cell fabrication using Azadirachta indica (Neem) leaves extract as both capping and reducing agent. The hexagonal structure of ZnO nanoparticles was confirmed by X-ray powder diffraction analysis. The Fourier-transform infrared spectrum confirms the presence of Zn–O stretching vibrations. High-resolution transmission electron microscopy images have exhibited the spherical morphology of ZnO nanoparticles which has clearly illustrated the average particle size around 4.2 nm. The selected area electron diffraction pattern contains well uniform rings confirming standard orientation. The maximum absorption wavelength for the synthesized ZnO nanoparticles was found to be more than 352 nm. The electrical measurement demonstrated that the values of dielectric constant and dielectric loss gradually decrease with increase in frequency which is described by the basis Maxwell–Wagner model. The ac conductivity of ZnO nanoparticles was also carried out. The solar cell fabrication of ZnO nanoparticles and photovoltaic devices were displayed. It was further confirmed that smaller size of ZnO nanoparticles was synthesized which had shown better cell efficiency.
关键词： microwave oven,ZnO nanoparticles,green synthesis,Azadirachta indica,solar cell
更新于2025-09-16 10:30:52
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Laser ablation in liquids for the assembly of Se@Au chain-oligomers with long-term stability for photothermal inhibition of tumor cells
摘要： For the potential use of Au nanoparticles (NPs) in photothermal therapy, it is important and effective to achieve the uniaxial assembly of Au NPs to allow enhanced absorption in the near infrared (NIR) region. Herein, we first presented the construction of amorphous selenium encapsulated gold (Se@Au) chain-oligomers by successive laser ablation of Au and Se targets in sodium chloride solution without other toxic precursors, stabilizers, or templating molecules. Se@Au chain-oligomers showed evidently enhanced NIR absorption and excellent photothermal transduction efficiency (g), which was higher than 47% at 808 nm. After being stored for 1 year, the Se@Au colloids still exhibited outstanding photothermal performance. The cytotoxicity assay demonstrated that there is negligible toxicity of Se@Au chain-oligomers in cells, but cell viability declined to only 1% in phototherapeutic experiments that were implemented in vitro. In intracellular Reactive Oxygen Species (ROS) generation measurements, Se@Au chain-oligomers could trigger a 35.9% increment of ROS upon laser irradiation. The possible synergetic effects between the anticancer function of Se and photothermal behaviors of Se@Au oligomers were intended to increase ROS level in cells. Therefore, such designed Se@Au chain-oligomers of high stability exhibit promising potential for their use as in vivo photothermal therapeutic agents.
关键词： Laser ablation,Se nanoparticle,Green synthesis,Au nanoparticle,Chain-oligomer,Photothermal therapy
更新于2025-09-16 10:30:52
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Microwave-Assisted and Green Fabrication of Carbon Quantum Dots from Viburnum opulus for Potential Bioimaging Applications
摘要： Early diagnosis is very strategic for today’s diseases such as cancer and infectious diseases. Most of the mortality in these diseases has not been diagnosed early and the mortality rates decrease significantly in early diagnosed cases. Carbon quantum dots (C-dots), which are fluorescent materials used in early diagnosis methods, are both novel and promising materials. The carbon quantum dots have proved their usefulness in bio-applications with this feature. Herein, we reported that a step facile-green microwave-assisted hydrothermal fabrication of C-dots was carried out from Viburnum opulus as a green substrate (Figure 1). The characterization of the fabricated C-dots from Viburnum opulus was accomplished by Fourier transform infrared spectroscopy (FT-IR), UV-vis spectrophotometer, and field-emission scanning electron microscope (FE-SEM). The carbon quantum dots have multifunctional properties that can be found in many areas. For example, they are important materials that can be used in high-performance nanoprobes, bio-imaging applications, molecule labeling applications, labeling and imaging techniques in cancer cells, and as contrast agents.
关键词： carbon quantum dots,bio-applications,green synthesis,Viburnum opulus
更新于2025-09-12 10:27:22