Cellulose acetate-Ce/Zr@Cu0 catalyst for the degradation of organic pollutant.

In the present work, Cu nanoparticles were stabilized on ceria/zirconia (Ce/Zr@Cu0), cellulose acetate (CA@Cu0), and a thin film of cellulose acetate embedded ceria/zirconia (CA-Ce/Zr) designated as CA-Ce/Zr@Cu0. In the presence of a reducing agent, all the catalysts revealed excellent catalytic efficiency in aqueous media for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) and degradation of cationic dyes methylene blue (MB) and rhodamine B (RB). Different order of equations were applied to determine the adjacent R2 value and rate constant. Adjacent R2 values for MB are 9.470, 9.422 and 9.050 and its kapp values per minutes are 1.7 × 10-1, 8.3 × 10-2, and 6. 7 × 10-1 with Ce/Zr@Cu0, CA@Cu0, and CA-Ce/Zr@Cu0 derived from the pseudo 1st order kinetics, while in the absence of catalyst the R2 and kapp for MB degradation in the presence of NaBH4 is 0.8643 and 3.4 × 10-3 respectively. Furthermore, regression models, ANOVA and correlation coefficients suggested that all the data are highly significant. The synthesized catalysts were applied for the simultaneous reduction/degradation of mixture of 4-NP-MB, 4-NP-RB and 4-NP-MB-RB mixture to check the practical applicability. Catalytic recyclability of CA-Ce/Zr@Cu0 catalyst dropped till 5th cycle which is due to the leaching of Cu0 NPs.

Isolation, characterization and DFT studies of epoxy ring containing new withanolides from Withania coagulans Dunal.

A new withanolide named as withacoagulin J (1) along with a known withanolide H (2) from Withania coagulans Dunal are reported in this paper. The isolated compounds were elucidated by using 1D-NMR (1H NMR, 13C NMR) and 2D-NMR including homonuclear (COSY, NOESY) and heteronuclear (HSQC, HMBC); along with Mass spectrometry, UV-Visible and IR spectroscopic techniques. The molecular formula based on Fast-Atom Bombardment Mass Spectrometry [FAB-MS (M + 1)] for 1 and 2 were deduced as C28H37O5 and C28H39O6 with m/z values 453.2624 and 471.6041, respectively. The quantum mechanical studies of both compounds are based on DFT calculations. The DFT studies show band gaps of 4.86 and 4.83 eV for 1 and 2, respectively. The band gaps of 1 and 2 reflect high stability and resistivity towards oxidation-reduction reactions. The energies of HOMO and LUMO for compound 1 are -6.11 and -1.25 eV and for compound 2: -6.47 and -1.64 eV respectively. Theoretical and experimental FTIR data closely match for both the compounds which support the high accuracy of the computational protocol selection. Other parameters such as bond lengths, bond angles and dihedral angles for both compounds are also studied.

A facile synthesis of CuAg nanoparticles on highly porous ZnO/carbon black-cellulose acetate sheets for nitroarene and azo dyes reduction/degradation.

A facile and highly porous heterostructure nanocomposite was designed for the support of zero-valent metal nanoparticles. This nanocomposite comprising of ZnO/carbon black (ZnO/CB) embedded in cellulose acetate polymer (CA), named as ZCA sheet, supported the metallic Cu, Ag and bimetallic CuAg nanoparticles (NPs). The ZnO/CB was incorporated to CA polymer host molecule in 3, 4 and 5 wt% and are designated as ZCA-3, ZCA-4 and ZCA-5. The catalytic tunability was evaluated for CuAg/ZCA-5 by adjusting the concentration of Cu and Ag ions in different molar ratio. Therefore, the CuAg/ZCA-5 was further selected for the removal of eight model pollutants comprising of o-nitrophenol (ONP), m-nitrophenol (MNP), p-nitrophenol (PNP), 2,6-dinitrophenol (DNP), methyl orange (MO), congo red (CR), methylene blue (MB) and rhodamine B (RB). The Kapp value for PNP was 1.9 × 10-1 min-1 and 9.0 × 10-2 min-1 for MO. Among the various nitrophenols, the rate of reaction with CuAg/ZCA-5 followed the ordered as PNP ˃ ONP ˃ MNP ˃ DNP, while methyl orange (MO) is degraded faster as compared to other dyes. The morphology, shape, elemental analysis, functional groups and peak crystallinity were scrutinized through FESEM, EDS, ATR-FTIR and XRD respectively.

Albizia chevalier based Ag nanoparticles: Anti-proliferation, bactericidal and pollutants degradation performance.

The eco-friendly biosynthesis of silver nanoparticles (AgNps) from bark extract of Albizia chevalier are reported here for their anti-proliferative, antibacterial and pollutant degradation potentials. The synthesized AgNps were characterized by FTIR spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive X-rays spectrometry (EDS) and X-ray diffraction studies. The TEM and FESEM images show a monodispersed spherical shaped particles of approximately 30 nm. Crystalline peaks were obtained for the synthesized AgNps in XRD spectrum. The AgNps were investigated for in vitro anticancer and antibacterial activities and its potential to degrade 4-nitrophenol (4-NP) and congo red dye (CR). The MTT results shows a significant dose-dependent antiproliferation effect of the AgNps on the cell lines HepG2, MDA-MB-231 and MFC7. The effect was found more pronounced in MDA-MB-231 as compared to MFC-7 cell lines. The antibacterial results indicated 99 and 95% killing of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) respectively, after 24 h of incubation with the AgNps. The AgNps were found to speed up the reductive degradation of 4-NP and CR dye, which give an alternative route for the removal of toxic organic pollutants from the wastewater. The synthesized AgNps were not only used as a bactericidal and anticancer agent, but also effectively used for the reductive degradation of carcinogenic compounds which are listed as the priority pollutants. Therefore, AgNps have the potential for the treatment of various cancers, bacterial infections and for industrial detoxification of wastewater.