Green synthesis of metal nanoparticles and study their anti-pathogenic properties against pathogens effect on plants and animals.

According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion worldwide. Among, all fruits the discarded portion of oranges is around 20%. A novel and value addition approach to utilize the orange peels is in nanoscience. In the present study, a synthesis approach was conducted to prepare the metallic nanoparticles (copper and silver); by utilizing food waste (Citrus plant peels) as bioactive reductants. In addition, the Citrus sinensis extracts showed the reducing activity against metallic salts copper chloride and silver nitrate to form Cu-NPs (copper nanoparticles) and Ag-NPs (Silver nanoparticles). The in vitro potential of both types of prepared nanoparticles was examined against plant pathogenic bacteria Erwinia carotovora (Pectobacterium carotovorum) and pathogens effect on human health Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Moreover, the in vivo antagonistic potential of both types of prepared nanoparticles was examined by their interaction with against plant (potato slices). Furthermore, additional antipathogenic (antiviral and antifungal) properties were also examined. The statistical analysis was done to explain the level of significance and antipathogenic effectiveness among synthesized Ag-NPs and Cu-NPs. The surface morphology, elemental description and size of particles were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and zeta sizer (in addition polydispersity index and zeta potential). The justification for the preparation of particles was done by UV-Vis Spectroscopy (excitation peaks at 339 nm for copper and 415 nm for silver) and crystalline nature was observed by X-ray diffraction. Hence, the prepared particles are quite effective against soft rot pathogens in plants and can also be used effectively in some other multifunctional applications such as bioactive sport wear, surgical gowns, bioactive bandages and wrist or knee compression bandages, etc.

Investigating structural and electronic properties of neutral zinc clusters: a G0W0 and G0W0Г0(1) benchmark.

The structural and electronic properties of zinc clusters (Znn) for a size range of n = 2-15 are studied using density functional theory. The particle swarm optimization algorithm is employed to search the structure and to determine the ground-state structure of the neutral Zn clusters. The structural motifs are optimized using the density functional theory approach to ensure that the structures are fully relaxed. Results are compared with the literature to validate the accuracy of the prediction method. The binding energy per cluster is obtained and compared with the reported literature to study the stability of these structures. We further assess the electronic properties, including the ionization potential, using the all-electron FHI-aims code employing G0W0 calculations, and the G0W0Г0(1) correction for a few smaller clusters, which provides a better estimation of the ionization potential compared to other methods.

Investigations on the structural and optoelectronic characteristics of cadmium-substituted zinc selenide semiconductors.

A change in the composition and dopant content of selective atoms in a material leads to their new desired properties by altering the structure, which can significantly improve the performance of relevant devices. By acknowledging this, we focused on characterizing the optoelectronic and structural properties of cadmium-substituted zinc selenide (Zn1-xCdxSe; 0 ≤ X ≤ 1) semiconductors using density functional theory (DFT) within the generalized gradient approximation (GGA), EV-GGA, and mBJ approximations. The results proved the cubic symmetry of the investigated materials at all Cd concentrations (0, 0.25, 0.50, 0.75, and 1). Although a linear surge in the lattice constant is observed with the change in Cd content, the bulk modulus exhibits a reverse trend. These materials are observed to be direct bandgap semiconductors at all Cd concentrations, with a decrease in electronic bandgap from 2.76 eV to 1.87 eV, and have isotropic optical properties, showing their potential applicability as a blue-to-red display. The fundamental optical properties of the materials, such as optical conductivity, reflectance, refractive index, absorption, and extinction coefficient, are also discussed. These outcomes provide a computational understanding of the diverse applications of Zn1-xCdxSe semiconductors in optoelectronic, photonic, and photovoltaic devices, particularly for a visible-range display.

Enhanced Bactericidal Action of rGO-ZnO Hybrids Prepared by the One-Pot Co-precipitation Approach.

Metal-based antimicrobials have the potential to profile sustainable solutions to infection care and health. In this study, we report the synthesis of rGO-ZnO hybrid nanostructures by a simple co-precipitation approach with various mass ratios of GO, and their antimicrobial potential was assessed. The structural analysis confirms the presence of a hexagonal wurtzite structure with peak shifting in hybrid nanostructures and increases in crystallite size (11-24 nm). Raman spectra revealed GO doping in the D band (1350 cm-1) and G band (1590 cm-1). Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were performed to investigate the surface morphologies of the synthesized sediments, which showed a change in the morphology of ZnO from non-uniform spherical nanoparticles to a rod-like morphology of the prepared hybrid nanostructures. RAMAN spectra revealed that the retained functional groups on rGO planes were significant in anchoring ZnO to rGO. At lowest and maximum doses of ZnO, substantial bactericidal zones (p < 0.05) for S. aureus (1.55 and 1.95 mm) and E. coli (1.25 and 1.70 mm) were achieved accordingly. Additionally, the inhibition regions were 2.45-3.85 mm and 3.75-6.85 mm for S. aureus whereas (2.05-3.25 mm) and (2.95-3.90 mm) for E. coli at the lowest and maximum concentrations.

Doping of Mg on ZnO Nanorods Demonstrated Improved Photocatalytic Degradation and Antimicrobial Potential with Molecular Docking Analysis.

Various concentrations of Mg-doped ZnO nanorods (NRs) were prepared using co-precipitation technique. The objective of this study was to improve the photocatalytic properties of ZnO. The effect of Mg doping on the structure, phase constitution, functional groups presence, optical properties, elemental composition, surface morphology and microstructure of ZnO was evaluated with XRD, FTIR, UV-Vis spectrophotometer, EDS, and HR-TEM, respectively. Optical absorption spectra obtained from the prepared samples showed evidence of blueshift upon doping. XRD results revealed hexagonal wurtzite phase of nanocomposite with a gradual decrease in crystallite size with Mg addition. PL spectroscopy showed trapping efficiency and migration of charge carriers with electron-hole recombination behavior, while HR-TEM estimated interlayer d-spacing. The presence of chemical bonding, vibration modes and functional groups at the interface of ZnO was revealed by FTIR and Raman spectra. In this study, photocatalytic, sonocatalytic and sonophotocatalytic performance of prepared NRs was systematically investigated by degrading a mixture of methylene blue and ciprofloxacin (MBCF). Experimental results suggested that improved degradation performance was shown by Mg-doped ZnO NRs. We believe that the product synthesized in this study will prove to be a beneficial and promising photocatalyst for wastewater treatment. Conclusively, Mg-doped ZnO exhibited substantial (p < 0.05) efficacy against gram-negative (G-ve) as compared to gram-positive (G+ve) bacteria. In silico molecular docking studies of Mg-doped ZnO NRs against DHFR (binding score: - 7.518 kcal/mol), DHPS (binding score: - 6.973 kcal/mol) and FabH (- 6.548 kcal/mol) of E. coli predicted inhibition of given enzymes as possible mechanism behind their bactericidal activity.

Enhanced physical properties of γ-Al2O3-rGO hybrids prepared by solvothermal and hot-press processing.

In this study, a solvothermal method was employed for the first time to fabricate hybrids composed of cross-linked γ-Al2O3 nanorods and reduced graphite oxide (rGO) platelets. After calcination and hot-press processing, monoliths of Al2O3-rGO hybrids were obtained with improved physical properties. It was found that the oxygen-containing groups on graphene oxide were beneficial for the adsorption of aluminum isopropoxide, leading to a uniform dispersion of rGO with Al2O3, which was obtained by hydrolysis of aluminum isopropoxide during the solvothermal reaction. The hybrid, which was subsequently calcinated for 3 h showed electrical conductivity of 6.7 × 101 S m-1 together with 90% higher mechanical tensile strength and 80% higher thermal conductivity as compared to the bare Al2O3. In addition, the dielectric constant of the hybrid was 12 times higher than that of the bare Al2O3. In this study, the highest values of electrical conductivity (8.2 × 101 S m-1), thermal conductivity (2.53 W m-1 K-1), dielectric constant (104) and Young's modulus (3.7 GPa) were obtained for the alumina-rGO hybrid calcinated for 1 h. XRD characterization showed that an increase in calcination temperature and further hot-press processing at 900 °C led to enhanced crystallinity in the γ-Al2O3 nanorods in the hybrid, resulting in enhanced physical properties in the hybrids.

Incorporating Pyrrolic and Pyridinic Nitrogen into a Porous Carbon made from C60 Molecules to Obtain Superior Energy Storage.

Nitrogen-doped porous carbon is obtained by KOH activation of C60 in an ammonia atmosphere. As an anode for Li-ion batteries, it shows a reversible capacity of up to ≈1900 mA h g-1 at 100 mA g-1 . Simulations suggest that the superior Li-ion storage may be related to the curvature of the graphenes and the presence of pyrrolic/pyridinic group dopants.

Supercapacitors: A Hierarchical Carbon Derived from Sponge-Templated Activation of Graphene Oxide for High-Performance Supercapacitor Electrodes (Adv. Mater. 26/2016).

H. Ji, Y. Zhu, and co-workers demonstrate a 3D hierarchically porous carbon by introducing a polyurethane sponge to template graphene oxide into a 3D interconnected structure while KOH activation generates abundant micropores in its backbone. As described on page 5222, a supercapacitor assembled with this carbon material achieves a high energy density of 89 W h kg(-1) (64 W h L(-1) ) and outstanding power density due to its shortened ion transport distance in three dimensions.

A Hierarchical Carbon Derived from Sponge-Templated Activation of Graphene Oxide for High-Performance Supercapacitor Electrodes.

A hierarchical porous carbon is fabricated by introducing a polyurethane sponge to a template graphene oxide into a 3D interconnected structure, while KOH activation generates abundant micropores in its backbone. Supercapacitors assembled with this carbon achieve a high energy density of 89 W h kg(-1) (64 W h L(-1) ) and outstanding power density due to the shortened ion-transport distance in 3D.