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CuO NPs is being applied for various applications including catalyst, electronics, cosmetics, and biomedicines due to its exceptional physicochemical properties. Physical and chemical routes for CuO NPs synthesis raised the concern of environmental hazard due to use of high energy, high temperature, and toxic chemicals. Conversely, green procedure is considered as an inexpensive and eco-friendly approach. To compare in vitro bioactivities and in vivo toxicity, CuO NPs was synthesized by two different methods; green and chemical routes. Leaf extract of a medicinal plant (Salacia reticulate) was used as a reducing and capping agent for green synthesis of CuO NPs. Sodium hydroxide was applied for chemical route of CuO NPs preparation. The in vivo toxicity of both CuO NPs (green and chemical) was examined in zebrafish (Dania rerio) embryos. Several in vitro biological activities e.g. antibacterial, cytotoxicity (in human cells), antidiabetic, and anti-inflammatory activities of both CuO NPs (green and chemical) was also assessed. Prepared CuO NPs (green and chemical) was characterized by SEM-EDX, FTIR, XRD, and UV–Vis spectroscopy. Several biomarkers such as hatching rate, malformation, and mortality rate of zebrafish embryos showed that green prepared CuO NPs exerted much lesser toxicity as compared to chemically synthesized CuO NPs. Antibacterial activity of green CuO NPs against Gram-negative (Escherichia coli, Staphylococcus aureus, and Enterobacter) and Gram-positive (Bacillus subtilis and Pseudomonas aeruginosa) bacteria was higher than chemical CuO NPs. Cytotoxicity results showed that human breast cancer cells (MCF-7) were more sensitive to green CuO NPs than chemical CuO NPs. Furthermore, antidiabetic and anti-inflammatory activities of green CuO NPs was greater than those of chemically prepared CuO NPs. This work revealed that in vitro bioactivities of green synthesized CuO NPs was better than chemically synthesized CuO NPs. Green CuO NPs also displayed higher biocompatibility towards zebrafish than chemical CuO NPs. This work highlights the importance eco-friendly green synthesis of CuO NPs for biomedical applications.

A new class of BaLiZn3(BO3)3:RE (RE = Sm3+, Tb3+, Dy3+, and Pb2+) phosphors were synthesized with a solid- state reaction method. The minor concentrations of various rare earth (Tb3+, Dy3+, and Sm3+) ions and transition metal (Pb2+) ions activated in the BaLiZn3(BO3) host matrix were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence spectroscopy. The XRD results of BaLiZn3(BO3)3:RE (RE = Sm3+, Tb3+, Dy3+, and Pb2+) phosphors confirmed that all the samples have a monoclinic phase. SEM studies revealed that the morphology of BaLiZn3(BO3)3:RE (RE = Sm3+, Tb3+, Dy3+, and Pb2+) phosphors was irregular. The photoluminescence emission and excitation spectra show that these phosphors can be effectively excited by near-ultraviolet light-emitting diodes (n-UV), and they all exhibit an efficient orange-red (Sm3+, 4G5/2 → 6H7/2), green (Tb3+, 5D4 → 7F5), yellow (Dy3+, 4F9/2 → 6H13/2), and blue (Pb2+, 3P1 → 1S0) emission. All of the above results confirmed that the obtained phosphors could be a potential candidate for n-UV-excited WLEDs. [ABSTRACT FROM AUTHOR]

A series of NaBaBi2[PO4]3 doped with Sm3+ (NaBaBi2−x[PO4]3:xSm3+; x = 0.025, 0.05, 0.075, 0.1, 0.3, and 0.5) phosphors were prepared using a solid-state reaction method in the present study. To evaluate the crystallinity and purity of the phosphor, XRD analysis was employed. To establish the morphology and elemental analyses of the phosphors, FESEM with EDX was adopted. Investigations into the phosphors’ photoluminescence properties were extensively studied. The phosphor exuded many strong Sm3+ ion emission peaks, oriented at 563, 601, and 644 nm, respectively. The transition 4G5/2 → 6H7/2 of Sm3+ emits the most vivid orange-red light at 601 nm. According to Dexter’s hypothesis, quenching happens as a result of dipole–dipole interaction at x = 0.1, the ideal concentration of the Sm3+ doped phosphor. The critical distance for phosphor is 17.27 Å. It was established that the phosphor’s band gap is Eg = 4.25 eV for the undoped compound. The phosphors’ CIE chromaticity coordinate appears to have fallen in the orange-reddish spectral range. It’s possible to employ the Sm3+-doped phosphors found in NaBaBi2[PO4]3 as orange-red phosphors in white light-emitting diodes. [ABSTRACT FROM AUTHOR]

Hybridized nanocatalysts (AgNPs-Fe2O3) were prepared with silver nitrate and ferric chloride in the presence of sodium borohydride. The synthesized nanocatalyst was calcined, milled, and sieved for further applications. The nanocatalyst was characterized using Fourier transform infrared spectroscopy (FTIR) for the identification of functional moieties involved in the synthesis of the nanocatalyst. The vibrations of Fe and Ag were found at 566, 790 and 892 cm-1. The crystalline nature of the nanocatalyst was determined using X-ray diffraction (XRD) studies. The diffraction peaks for Ag and Fe can be seen at 2θ values of 30.42, 44.36, 62.45, 42.24 and 53.25. The morphology and elemental analysis of nanocatalysts were studied using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX). The particles are found to be spherical in shape. The signal for Ag and Fe can be found at 3.0 keV and 0.7, 6.3, 7.0 keV, respectively. The synthesized nanocatalyst was employed in the remediation of 2,4-dinitrophenol. The AgNPs-Fe2O3 nanocatalyst completely reduced (97%) the 2,4-dinitrophenol to 2,4-diaminophenol within 24 h. [ABSTRACT FROM AUTHOR]

This study considered the removal efficiency of turbidity and organic content from high-turbidity storm water of tropical storm Nari, using polyaluminum chloride (PACl) as a coagulant. The resulting floc size and compactness (fractal dimension) were determined using a small-angle light scattering technique. The response surface method, and the Box-Behnken design, was adopted to examine how the hydrogen ion concentration (pH), turbidity, and alkalinity of the suspension, the PACl dosage, and the dosed amount of humic acid affect the removal efficiency. Flocs with a looser interior structure more efficiently removed turbidity and humic acid. An acidic suspension and moderate PACl dosage and alkalinity level favor the production of loose flocs. Optimal conditions for generating large flocs include pH neutrality and high PACl dosage. Producing both large and loose flocs depends on a compromise. The removal of turbidity/humic acid from high-turbidity storm water does not proceed by a charge neutralization mechanism. DOI: 10.1061/(ASCE)0733-9372(2003)129:6(571) CE Database subject headings: Turbidity; Acids; Chlorides; Fractals; Stormwater treatment.