Silver sulphide nanoparticles (Ag2SNPs) synthesized using Phyllanthus emblica fruit extract for enhanced antibacterial and antioxidant properties.

In this study, silver sulfide nanoparticles (Ag2SNP's) were successfully produced by using fruit extracts of Phyllanthus emblica. UV-vis, FTIR, XRD with SEM and EDX techniques were used for the synthesis process and for characterization of the resulting nanostructures. According to the findings, the fabricated nanostructure had a monoclinic crystal structure, measuring 44 nm in grain size, and its strain was 1.82 × 10-3. As revealed by SEM analysis, the synthesized nanostructure consists of irregular spherical and triangular shapes. The presence of silver (Ag) and sulfur (S) was also confirmed through EDX spectra. Furthermore, Ag2S nanoparticles were tested for their ability to effectively inhibit gram-positive and gram-negative bacterial growth. As a result of this study, it was clearly demonstrated that Ag2S nanoparticles possess powerful antibacterial properties, particularly when it came to inhibiting Escherichia coli growth. Ag2S nanoparticles had high total H2O2 and flavonoid concentrations and the greatest overall antioxidant activity, according to the evaluation of antioxidant activity of the samples. The results obtained from the P. emblica fruit extract were followed by those obtained from Ag2S nanoparticles were reported in detail. RESEARCH HIGHLIGHTS: Innovative Ag2SNP synthesis using Phyllanthus emblica fruit extract. SEM with EDX revealed a monoclinic crystal structure with a grain size of 44 nm and a strain of 1.82 × 10-3. Many of these applications are demonstrated by the potential of Ag2SNPs to treat and combat bacteria, particularly Escherichia coli. A peak at 653 cm-1 indicates the presence of primary sulfide aliphatic C-S extension vibrations. The abundant H2O2 and NO2 found in P. emblica nanocomposites make them potent antioxidants.

Extraction of Natural Pigment Curcumin from Curcuma Longa: Spectral, DFT, Third-order Nonlinear Optical and Optical Limiting Study.

Herein, we report the extraction of natural pigment curcumin from curcuma longa and their linear and third-order nonlinear optical (NLO) characteristics. The characterization techniques viz., UV-Visible absorption, FT-IR, Micro Raman and Gas Chromatography Mass Spectrum (GC-MS) are used to study the spectral characteristics of curcumin. Third-order NLO features of curcumin are studied using Z‒scan technique with a semiconductor diode laser working at 405 nm wavelength. The natural pigment exhibits negative nonlinear index of refraction resulting from self-defocusing and positive coefficient of absorption is the consequence of reverse saturable absorption (RSA). The order of nonlinear index of refraction (n2) and nonlinear coefficient of absorption (ß) is measured to be 10-7 cm2/W and 10-2 cm/W, respectively. Third-order NLO susceptibility (χ(3)) and second-order hyperpolarizability (γ) of curcumin is measured to be 2.73 × 10‒7 esu and 1.67 × 10‒31 esu, respectively. A low optical limiting (OL) threshold of 0.71 mW is observed in the extracted pigment. The experimental results are supplemented by quantum mechanical calculations of the NLO parameters. The overall result finding is that curcumin extracted from curcuma longa has the potential to be novel optical candidates for photonics and optoelectronics applications.

Correction: Siddhardha et al. Chrysin-Loaded Chitosan Nanoparticles Potentiates Antibiofilm Activity against Staphylococcus aureus. Pathogens 2020, 9, 115.

The authors wish to make the following corrections to the original publication [...].

Retraction: Anti-cancer activity of hierarchical ZSM-5 zeolites synthesized from rice-based waste materials.

[This retracts the article DOI: 10.1039/C7RA11763A.].

Self-assembly of CdSe 3D urchins and their photocatalytic response.

Photocatalysis is found to be one of the best suited processes that respond to the purification of water systems and the semiconductor nanomaterials are learned to be incredible materials which carry out the photocatalytic process as they readily decompose the pollutants effectively. In this present work, CdSe nanoparticles belonging to II-VI group semiconductor compounds were synthesized using a facile hydrothermal process with different precursor concentrations and were analysed for various characterization studies such as X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Photoluminescence (PL) studies. The XRD study of the synthesized CdSe nanostructures revealed that the average crystallite size was ranging from 18.5 nm to 24 nm pointing out the increase in size with increase in molar concentrations. The morphological structure of synthesized CdSe samples exhibited urchin-like structure for a lower concentration with several rod-like projections appearing in diverse directions. These CdSe nano-urchins synthesized with lower concentrations are found suitable to carry out the process of photocatalytic activity. The process was carried out under visible light radiation for 180 min with aqueous solution of methylene blue (MB) as the ideal toxin to be degraded. The attained degradation efficiency was nearly 80% clearly displaying that the synthesized samples are good photocatalysts. By tuning the bandgap, through the optimization of the precursor concentrations, greater efficiency can be achieved in future.

Photocatalytic degradation effect of CdSe nanoparticles for textile wastewater effluents at low cost and proves to be efficient method.

Semiconductor nanoparticles and nanocrystals have a great impact due to its contribution in the diverse fields including electronics, solar energy, biological imaging, and photonics. Among these semiconductor nanoparticles, cadmium selenide of II-VI group binary semiconductor nanoparticles were synthesized using solvothermal process for the different reaction temperatures. The XRD pattern of the synthesized samples confirms the crystalline nature of the samples and showed increase in its crystallite size with rise in temperature. The morphology of the samples was analysed with TEM images and found that the nanoparticles synthesized at different temperatures were varied in size and shape indicating the increase in the size of the particles with the raise in temperature. The optical properties of the samples pointed out that they exhibit a blue shift owing to quantum confinement. Photocatalytic activity was carried out for the synthesized samples under visible light radiation using methylene blue (MB) as a model pollutant and it proved to be a good photocatalyst achieving the efficiency of 75% which is promising for future application with good optimization. The efficiency could be increased when these semiconductor CdSe nanoparticles are doped with metal particles due to an increase in the absorption edge wavelength and a decrease in bandgap energy were reported in detail.

A novel approach for engineering efficient nanofluids by radiolysis.

This contribution reports for the first time the possibility of using radiolysis to engineer stable efficient nanofluids which exhibit an enhanced thermal conductivity. The validation was confirmed on Ag-H2O and Ag-C2H6O2 nanofluids fabricated via g-radiolysis within the mild dose range of 0.95 × 103-2.45 × 103 Gray. The enhanced thermal conductivity of Ag-H2O and Ag-C2H6O2 nanofluids, was found to be g-radiations dose dependent. In the latter case of Ag-C2H6O2 nanofluid, the relative enhancement in the temperature range of 25-50 °C was found to be 8.89%, 11.54%, 18.69%, 23.57% and 18.45% for D1 = 0.95 × 103 Gray, D2 = 1.2 × 103 Gray, D3 = 1.54 × 103 Gray, D4 = 1.80 × 103 Gray and D5 = 2.45 × 103 Gray respectively. Yet not optimized, an enhancement of the effective thermal conductivity as much as 23.57% relatively to pure C2H6O2 was observed in stable Ag-C2H6O2 nanofluids. Equivalent results were obtained with Ag-H2O.

On the remarkable nonlinear optical properties of natural tomato lycopene.

In line with the renewed interest in developing novel Non Linear Optical (NLO) materials, natural Lycopene's NLO Properties are reported for the first time within the scientific literature. Correlated to its 1-D conjugated π-electrons linear conformation, it is shown that natural Lycopene exhibits a significantly elevated 3rd order nonlinearity χ(3) as high as 2.65 10-6 esu, the largest value of any investigated natural phyto-compound so far, including ß-carotene. In addition to a saturable absorption, the corresponding observed self-defocusing effect in Lycopene seems to be the result of a thermal nonlinearity. The nonlinear response coupled to the observed fluorescence in the Visible spectral range points to a potential photodynamic therapy application as well as the possibility of engineering of novel hybrid Lycopene based NLO nano-materials.

Laser induced plant leaf extract mediated synthesis of CuO nanoparticles and its photocatalytic activity.

Metal nanoparticles furnished by the green synthesis approach have exhibited fascinating attributes owing to their biocompatibility with biomolecules, and their rapid environmentally friendly synthesis. On copper oxide (CuO) nanoparticles, a laser induced bio reduction work has been accomplish using Centella asiatica aqueous extract at room temperature is the pioneer in the field. This synthesis technique is easy, fruitful, eco-friendly, and counterfeit for the size-tunable synthesis of diverse shapes of stable copper nanoparticles. UV-visible spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy - Dispersive X-ray Spectroscopy (EDX), X-ray diffraction (XRD) and photodegradation study have astounding properties of regulating the formation, crystalline nature, and morphology of an integrated specimen. Moreover, the obtained copper oxide nanoparticle has the tendency to decrease the absorbance maximum value of methylene blue because of the catalytic activity posed by these nanoparticles on the reduction of methylene blue by Centella asiatica. It has been studied and confirmed by UV-visible spectrophotometer, and it has been recognised as an electron relay effect.

Green synthesized hydroxyapatite nanoadsorbent for the adsorptive removal of AB113 dye for environmental applications.

The present work reports the synthesis of hydroxyapatite (HAp) via the green chemistry approach by using the leaf extract of copper pod tree and its adsorptive potential to remove Acid blue 113 (AB113) dye. FESEM-EDS characterization of the synthesized HAp confirmed rod-shaped HAp with prominent Ca and P elements. The crystallinity of HAp was ascertained by XRD and thermal stability was analyzed by TGA. The colloidal suspension stability was determined as - 17.7 mV by Zeta potential analyzer. The mesoporous structure was affirmed via BET studies with a high magnitude of specific surface area. TEM studies substantiated the rod-shaped HAp as observed in FESEM. The signals specific to HAp were observed in XPS studies. Adsorption of AB113 on the synthesized HAp was examined by varying the process parameters. Batch experiments resulted in an optimum dye removal of 92.72% at a pH of 8, 1 g/L of CP-HAp nps dosage, 20 ppm AB113 concentration, 120 min contact time, 150 rpm agitation speed and at room temperature. The maximum adsorption capacity reached 120.48 mg/g. Multifarious isotherms characterized the adsorption with Freundlich isotherm (R2 > 0.968) dominating Langmuir indicating multilayer adsorption. The experimental data reasonably matched pseudo-second-order kinetics with R2 exceeding 0.99. Thermodynamic investigations underlined the spontaneity and exothermicity of the processes. Results showed the suitability of the HAp nanoadsorbent to remove AB113 from wastestreams.

Regeneration study of MB in recycling runs over nickel vanadium oxide by solvent extraction for photocatalytic performance for wastewater treatments.

Recently, researchers are concentrating on the synthesis of composite materials to enhance the efficiency of the materials in various applications. In this work, nickel vanadium oxide (NiV2O6) nanocomposite material is prepared via two methods and the prepared samples have been characterized with basic studies to analyse the effect of preparation method and the reaction time. The XRD studies reveal a polycrystalline growth in both the methods. The broad XRD peaks obtained for samples prepared via hydrothermal method suggests the size reduction and 1D nanostructure formation. The SEM analysis shows the formation of 1D structures in hydrothermal and 3D microsphere structures in solvothermal methods. The possible formation mechanism behind this formation has been discussed in this manuscript. The FTIR peaks in the fingerprint region confirm the formation and vibration of metal-oxygen bonds. The large optical bandgap values obtained from Tauc plot again confirms the formation of nanostructures of the synthesized samples. The photocatalytic activity of nickel vanadium oxide on methylene blue dye under halogen light were performed and, the recyclability of the sample is investigated. It was found from the photocatalytic spectrum that, the samples prepared from both the methods shows a degradation efficiency of more than 80% within 150 min. It was confirmed that the prepared NiV2O6 photocatalyst samples does not lose their degradation ability even after five cycles of repeated usage.

Reproducibility and long-term stability of Sn doped MnO2 nanostructures: Practical photocatalytic systems and wastewater treatment applications.

Sn-doped MnO2 were synthesized as an oxidant, a mediator of maleic acid (C4H4O4) and SnCl2 as doping ingredient via a basic sol-gel reaction with KMnO4. XRD study signposts that tetragonal crystal structure of MnO2 (ICDD#44-0141) with a plane group of 12/m (87) for both pure and Sn doped MnO2 nanostructures. The photocatalyst synthesized has mesoporosity, allowing to the N2 adsorption/desorption experiments. The geometry of the materials varies from spherical shape in pristine MnO2 to a rod-like shape in Sn-MnO2, as observed in the SEM and TEM pictures. To examine optic properties and energy bandgaps topologies, UV-visible diffuse reflectance spectroscopy was applied. In visible spectrum, overall catalytic performance of Sn-doped MnO2 was tested using methyl orange and phenol as dyes. The results suggest that the optimized Sn doped MnO2 (10 wt.%) catalyst showed higher degradation efficiency (98.5%), apparent constant (0.7841 min-1) and long term permanence. For this improved charge extraction efficiency, a potential photocatalytic mechanism was proposed.

Enhancing the photocatalytic performance of surface - Treated SnO2 hierarchical nanorods against methylene blue dye under solar irradiation and biological degradation.

Surfactant -treated tin oxide (SnO2) hierarchical nanorods were successfully synthesized through hydrothermal technique. The X-ray diffraction analysis showed the prepared SnO2 possesses tetragonal rutile structure having appreciable crystallinity with crystallite sizes in the range of 110 nm-120 nm. UV-visible diffuse reflectance absorption spectra confirm that the better visible light absorption band of SnO2 hierarchical nanorods have red shift compared to the pure SnO2. Fourier transform infrared spectroscopy (FTIR) study evident that the as-prepared SnO2 nanorods encompass the characteristic bands of SnO2 nanostructures. The morphological analyses of prepared materials were performed by FESEM, which shows that hierarchal nanorods and complex nanostructures. EDX analyses disclose all the samples are composed of Sn and O elements. The photocatalytic performance of the prepared surfactant treated SnO2 hierarchical nanorods was evaluated using methylene blue (MB) dye removal under direct natural sunlight. Recycling experiment results of CTAB - SnO2 nanorods and photocatalytic reaction mechanism also discussed in detail.

Superparamagnetic hematite spheroids synthesis, characterization, and catalytic activity.

The leaf extract of Muntingia calabura is being first reported to be used for the synthesis superparamagnetic hematite nanoparticles by following the green-chemistry approach. Field Emission - Scanning Electron Microscopic image revealed the formation of irregular nano spheroids averaging at 48.57 nm in size and characteristic of Fe and O atoms, as revealed by Energy Dispersive X-Ray spectrum. X-ray diffraction analysis results proved the crystallinity of hematite diffraction planes with crystallite sizes averaging at 30.68 nm. The lattice parameter values stayed concordant with the literature. The superparamagnetic nature was attested by the high value of saturation magnetism (2.20 emu/g) with negligible coercivity and retentivity. Fourier Transform Infrared Spectroscopy results affirmed numerous moieties involved in the synthesis of hematite nanoparticles and the existence of signature Fe-O bands. Thermogravimetric analysis studies portrayed the thermal behavior nanoparticles with 28% weight loss and thermal stability was attained after 700 °C. X-ray photoelectron spectroscopy analysis confirmed the valence states of Fe and O in the hematite nanoparticles and ascertained the purity. The mesoscopic structure was revealed by Brunauer-Emmett-Teller studies with considerable surface area (112.50 m2/g). The Fenton-like catalysis mediated by the nanoparticle sample was demonstrated by degrading methylene blue dye. The remarkable degradation efficiency of 93.44% was obtained and the kinetics was conformed to a second-order model with a high R2 value. Therefore, the highly crystalline and mesoporous superparamagnetic hematite spheroids prepared using the leaf extract of M. calabura would find promising applications in various catalysis processes.

Photocatalytic effect of CuO nanoparticles flower-like 3D nanostructures under visible light irradiation with the degradation of methylene blue (MB) dye for environmental application.

The present research work focuses on preparing 3D transition metal doped copper oxide nanostructures through sonication method and to investigate the effect of doping different transition metal into copper oxide (CuO) on the basic properties of CuO nanoparticles and, to study the photocatalytic behaviour of the doped CuO samples. The morphological studies performed with the help of SEM revealed the formation of flower like CuO 3D nanostructures for all the doped samples. The slight shift in the position of peaks in the x-ray diffraction (XRD) pattern confirms that doping has been successfully done into CuO. Also, the sharp diffraction peaks suggest the polycrystalline nature of the sample with monoclinic structure. The UV-vis absorption analysis reveals a bandgap of 2.26, 2.12 and 2.15 eV for the CuO samples doped with nickel, zinc, and iron respectively via Tauc plot. The photocatalytic performance of the samples tested through the degradation of methylene blue (MB) dye suggests that samples doped with Zn shows better degradation. Thus, it is evident that the morphology and the optical properties of the CuO can be tailored by doping transition metal into it.

Adsorption of copper and nickel by using sawdust chitosan nanocomposite beads - A kinetic and thermodynamic study.

The adsorption behavior of biomaterial activated Sawdust-Chitosan nanocomposite beads (SDNCB) powder was investigated along with synthesis and experimental techniques approaches to study the removal efficiency of some heavy metal ions including Ni (II) and Cu (II) ions from aqueous solutions by assessing the surface-modified activated carbon by the cost-effective non-conventional method. Structural analysis of the entitled compound was evaluated by the PXRD techniques and its surface morphology was inferred by the following techniques: TEM, EDAX. The behavior of the functional group presents in the compound was discussed using the FTIR technique. Such parameters like dosage, pH, time, temperature, and initial concentration of copper and nickel were associated with this to examine the effect of adsorption of heavy elements that exist in the portable solution. Further, the cellulose and chitosan beads complex material have an appropriate surface area, it demonstrated metal ions removal efficiency was more appreciable due to the action of activated carbon, where this showed fast rate sorption kinetics due to strong involvement of Cu+ & Ni+ towards cellulose and chitosan's functional groups in the bio composite. The isotherm model so-called Langmuir, Freundlich, and Temkin model was utilized to plot the experimental adsorption dataset to infer the maximum adsorption capacity. Based on this model, the adsorption properties of the beads treated compound was determined by plotting the graphs in which sorption intensity (n) which implies expected sorption, and the correlation value are 1.989, 0.998, and 0,981 respectively.

Effect of Ag doped MnO2 nanostructures suitable for wastewater treatment and other environmental pollutant applications.

A modest sol-gel method has been employed to prepare the pure and Ag doped MnO2 nanoparticles and methodologically studied their physical, morphological, and photosensitive properties through XRD, TEM, EDAX, Raman, UV, PL and N2 adsorption - desorption study. Tetragonal crystalline arrangement with spherical nanoparticles was found out through XRD and TEM studies. The EDAX studies further supported that formation Ag in the MnO2 crystal matrix. The bandgap energy of Ag doped MnO2 was absorbed through UV spectra. Photo -generated recombination process and surface related defects were further recognized by PL spectra. Through visible light irradiation, the photo - degradation of methyl orange (MO) and phenol dye solutions were observed. The optimum condition of (10 wt% of Ag) Ag doped MnO2 catalyst showed tremendous photocatalytic efficiency towards MO than phenol under same experimental study.

Gum mediated synthesis and characterization of CuO nanoparticles towards infectious disease-causing antimicrobial resistance microbial pathogens.

BACKGROUND: In this work biologically active CuO nanoparticle were discussed. The literature suggests that CuO shows very good antibacterial activity on both Gram positive and Gram-negative bacterial strains. Further, it is used in antibacterial coatings on various substrates to prevent various kinds of medical equipment's. Here CuO NPs was prepared via greener approach and almond gum is used as a reducing agent. Almond gum is nontoxic and contains huge amount of polysaccharides. Hence, the gum mediated CuO NPs can be used to treat urinary tract infection (UTI). METHOD: The CuO NPs were characterized using UV, FTIR, XRD and HESEM with EDX analysis. The antibacterial (both Gram positive and Gram negative) effects of CuO NPs were determined with agar well diffusion method. RESULTS: The CuO NPs were characterized by X-ray diffraction pattern result indicates that the monoclinic structure with average crystallite size about 12.91 nm. Straight line model in Scherrer method results found to be crystallite size. The crystallite size and microstrain were estimated in W-H analysis. Lorentz polarization factor, size-strain plot (SSP), morphological index (M-I) and dislocation density were calculated based on x-ray diffraction data. The FTIR analysis confirms presence of Cu and O band. From the absorption spectrum of CuO NPs, it was found to be cutoff wavelength of 230 nm and direct bandgap was found to be 4.97 eV. Morphology analysis shows that the synthesized of CuO NPs reveals agglomerated and spherical in shape. It was found to be 16 nm-25 nm. Energy dispersive spectroscopy (EDX) result indicates percentages of Cu and O element present in the sample. Antimicrobial studies reveal zone of inhibition of CuO NPs. This was used in different pathogens such as gram-positive and Gram-negative bacteria. This study shows exhibit excellent antimicrobial effects of CuO NPs. CONCLUSION: Hence, in this article the novel and cost-effective method to prepare CuO NPs was discussed. The prepared CuO NPs can be used as an antifungal and antibacterial reagent.

Biosynthesis, characterization, and antibacterial activity of gold nanoparticles.

BACKGROUND: In recent decades focus of research has been toward an alternative antibacterial agent because of growing bacterial resistance and side effects of antibacterial agents. In the current study, the antibacterial activity of gold nanoparticles has been evaluated on selected human pathogens. METHODS: In this study, we used panchagavya (PG) to synthesize gold nanoparticles, and the resulting nanoparticles (PG-AuNPs) were characterized by several spectroscopic techniques. In addition, antibacterial activity of PG-AuNPs against Escherichia coli, Bacillus subtilis, and Klebsiella pneumoniae were studied by well diffusion method. RESULTS: The synthesis of AuNPs was affirmed by a colour change, which was further validated by UV-vis spectra with a maximum absorption peak at 527 nm. Bandgap energy was calculated as 2.13 eV by Tauc method from the UV result. The presence of amino acids and proteins in PG was responsible for the conversion of gold ions to AuNPs, according to FTIR analysis. (111), (200), (220), and (311) crystallographic planes were observed by XRD; further crystalline nature was validated by SAED analysis. The size and zeta value were found to be 53.29 nm and -9.8 mV respectively. Spherical shaped nanoparticles and elemental structure of PG-AuNPs were confirmed by HRTEM and EDS analysis. The antibacterial activity of PG-AuNPs showed the maximum and minimum zone of inhibition against K. pneumoniae (17.12 ± 0.14 mm) and B. subtilis (11.42 ± 0.58 mm). CONCLUSION: Antibacterial activity of PG-AuNPs was found to be strong against gram negative bacteria and moderate against gram positive bacteria. Based on the result, it was concluded that PG-AuNPs could be used to combat antibiotic drug resistance. Besides, in vitro and in vivo toxicity studies of PG-AuNPs should be conducted.

Systematic green synthesis of silver oxide nanoparticles for antimicrobial activity.

In this present research, we succeeded in synthesizing nanostructured silver particles (NS-AgPs) using bio active agent present in the leaf extracts of Cleome gynandra (CG) under green synthesis. While adding silver nitrate (AgNO3) solution in green extracts of CG leaf containing bio compound, the mixture turns from yellow to reddish brown, as a consequence of existence of nanostructured silver particles (NS-AgPs) and later UV instrument is used to obtain the Ultraviolet visible spectroscopy (UV-vis) spectra to confirm existing nanostructured silver particles (NS-AgPs) in aqueous solutions (synthesized sample). To confirm existing functional groups in NS-AgPs, the fourier transform infrared spectroscopy (FTIR) study is carried throughout this research. The scanning and tunneling of wave like nature of electrons passing through powdered NS-AgPs sample gives Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) images respectively, which are carried out to find out the 2-dimensional size and shape distribution of NS-AgPs. Further dynamic light scattering (DLS) and zeta potential studies are used to confirm the size and good stability of NS-AgPs respectively. It is evident that NS-AgPs exhibits a strong toxic activity against microorganism and to confirm this mechanism the antibacterial (against Escherichia coli and Staphylococcus aureus) study is carried out.