Dysprosium Incorporated Into Balsalazide Trapped Between the Functionalized Halloysite and g-C3N4 as an Efficient and Heterogeneous Catalyst for the Synthesis of Chromene Derivatives

An efficient and heterogeneous novel Dy complex of balsalazide, trapped between the functionalized halloysite and g-C3N4, was successfully synthesized by post-synthetic modification approach (Dy@Hal-BS-g-C3N4). It was characterized by several advanced analytical methods including, FT-IR, SEM, EDX, elemental mapping, XRD, ICP-OES and TGA. The as-synthesized material was catalytically explored as a novel recoverable nanocatalyst in the synthesis of an array of biologically active pyran derivatives, i.e., the 2-amino-5,10-dioxo-4-aryl-5,10-dihydro-4H-benzo[g]chromene-3-carbonitriles. Excellent yields of the desired products and facile reusability of the catalyst are the two advantageous factors in the introduction of this novel catalytic system.

Cobalt–Carbon Nanoparticles with Silica Support for Uptake of Cationic and Anionic Dyes from Polluted Water

Silica-supported hierarchical graphitic carbon sheltering cobalt nanoparticles Co-HGC@SiO2 (1) were prepared by pyrolysis at 850 °C of [Co(phen)(H2O)4]SO4.2H2O complex with silica in the presence of pyrene as a carbon source under nitrogen atmosphere. Nanocomposites (2) and (3) were obtained by acid treatment of (1) with HCl and HF acid, respectively. The nanocomposites showed rough hierarchical carbon microstructures over silica support decorated with irregular cobalt nanospheres and nanorods 50 to 200 nm in diameter. The nanoparticles consist of graphitic shells and cobalt cores. SEM, EDAX and TEM elemental mapping indicate a noticeable loss of cobalt in the case of (2) and loss of cobalt and silica in the case of (3) with an increase in porosity. Nanocomposite (3) showed the highest BET surface area 217.5 m2g−1. Raman spectrum shows defect D-band and graphitic G-band as expected in carbon nanostructures. PXRD reveals the presence of cobalt(0) nanoparticles. XPS indicates the presence of Co(II) oxides and the successful doping of nitrogen in the nanocomposites. Moreover, TEM elemental mapping provides information about the abundance of Si, Co, C, N and S elements in zones. Nanocomposite (1) showed maximum uptake capacity of 192.3 and 224.5 mg/g for crystal violet CV and methyl orange MO dyes, respectively. Nanocomposite (2) showed a capacity of 94.1 and 225.5 mg/g for CV and MO dyes, respectively. Nanocomposite (4) obtained after treatment of (1) with crystal violet proved successful adsorption of CV. Co-HGC (5) prepared without addition of silica has a capacity for CV equal to 192 mg/g, while it is 769.2 mg/g with MO. Electrostatics and π–π interactions of graphite and cobalt species in the nanocomposites with aromatic rings of cationic and anionic dyes are responsible for the adsorption. Yan et al. was the best model to describe column kinetics. The thomas column adsorption model showed that the maximum uptake capacity of (1) was 44.42 mg/g for CV and 32.62 mg/g for MO. for a column packed with 0.5 gm of (1) and dye concentration of 100 mg/L at a flow rate of 1 mL/min. The column was recycled three times with no noticeable clogging or degradation of nanocomposites. Thus, Co-HGC@SiO2 adsorbents can be used efficiently to treat water contaminated with cationic and anionic dyes.

X-ray computed tomography (CT) and ESEM-EDS investigations of unusual subfossilized juniper cones

Recent investigations of a Greco-Roman site at Sais have provided well-preserved archaeobotanical remains within a pile of metal fragments. The remains are compared with comparable modern taxa. The morphology and anatomy are studied using Light microscope (LM), Environmental scanning electron microscope (ESEM) and X-ray computed tomography (CT). To investigate the preservation mode, Energy dispersive spectroscopy (EDS) analysis and elemental mapping are conducted. Results revealed that the archaeobotanical remains are exhibiting close affinity with modern juniper cones. Although, the studied archaeobotanical remains are buried for more than 2 millenniums, they underwent early stages of silicification and copper mineralization. These results are discussed in relation to other excavated objects in the find and to our knowledge and understanding of daily life in the Greco-Roman period.

Nanosilver Immobilized in Carbonaceous Particles Derived from Hydrothermal Carbonization of Eleusine indica Leaf Extract

In this study, for the first time, hydrothermal treatment of Eleusine indica leaf extract and silver nitrate produced nanosilver immobilized in hydrothermal carbon synthesized at different reaction times (RT) - 6, 12, 24 and 48 h. The surface morphology of nanosilver hydrochar (AgNP@hydrochar) composites was studied using SEM, while their chemical functionalities were investigated using FT-IR, UV-Vis, XRF and EDX spectroscopy. The AgNP@hydrochar were observed to be agglomerated spherical particles with size ranges from 128 to 171 nm. Varying C=O and C=C IR absorption peaks at different RT suggested that the plant extract reduced Ag+ into Ag0 in solution. Elemental analysis using EDX showed that Ag is dominant in the composite (84.07 %) supported by the Ag spatial distribution as demonstrated by the EDX elemental mapping. HIGHLIGHTS For the first time, hydrothermal treatment of Eleusine indica leaf extract with silver nitrate resulted in nanosilver trapped in hydrothermal carbon HTC process of E. indica extract produced composite having agglomerated spherical particles EDX elemental mapping showed an abundant silver in the synthesized composite GRAPHICAL ABSTRACT

Facile Synthesis of Crosslinked Cu:ZnS-Lignocellulose Nanocomposite: A Potent Antifungal and Antisporulant System Against The Tea Pathogen Exobasidium Vexans

The objective of the present study was to synthesize Cu doped ZnS nanocore crosslinked with lignocellulose (represented as Cu:ZnS-lignocellulose nanocomposite) for antifungal action against the devastating tea blister blight pathogen Exobasidium vexans. The characteristic features of the nanocomposite were analyzed via different physicochemical techniques like FTIR, XRD, XPS, SEM, SEM-EDX, Elemental mapping, PCS, and UV-PL studies. The FTIR and XPS investigations revealed the crosslinking between lignocellulose and the Cu:ZnS. The presence of lignocellulose was seen to attribute a potent antifungal efficacy, also enhancing the stability of the resulting nanocomposite in aqueous suspensions. The antifungal efficacy confirmed through disk diffusion and broth dilution assays have a maximum zone of inhibition of 1.75 cm2 and a MIC50 of 0.05 mg/ml against E. vexans. Additionally, the antisporulant activity was evident as the basidiospores failed to germinate in presence of the Cu:ZnS-lignocellulose nanocomposites. This shows potential for stemming the rapid infectivity of E. vexans by achieving disease inhibition at the early stage. Finally, the comparison with two commonly used commercial fungicides (copper oxychloride and fluconazole) demonstrated > 10-fold higher antifungal activity for Cu:ZnS-lignocellulose nanocomposites.