title: Facile green fabrication of nanostructure ZnO plates, bullets, flower, prismatic tip, closed pine cone: Their antibacterial, antioxidant, photoluminescent and photocatalytic properties.
abstract: Green synthesis of multifunctional Zinc oxide nanoparticles (NPs) with a variety of morphologies were achieved by low temperature solution combustion route employing neem (Azadirachta indica) extract as fuel. The nanoparticles were characterized by PXRD, FTIR, XPS, Raman and UV-Visible spectroscopic studies. The Morphologies were studied by SEM and TEM analysis. The NPs were subjected for photoluminescence, photocatalytic, antibacterial and antioxidant activity studies. PXRD pattern confirmed the hexagonal wurtzite structure of the product. SEM images indicated the transformation of mushroom like hexagonal disks to bullets, buds, cones, bundles and closed pine cone structured NPs with increase in the concentration of neem extract in reaction mixture. The NPs exhibited prominent green emission due to the presence of intrinsic defect centers. The as-formed bullet shaped ZnO with 4ml of neem extract was found to decolorize Methylene blue (MB) under Sunlight and UV light irradiation. The antibacterial studies indicated that ZnO NPs of concentration 500, 750 and 1000μg resulted in significant antibacterial activity on Klebsiella aerogenes and Staphylococcus aureus but not against Escherichia coli and Pseudomonas aeruginosa in agar well diffusion method. Further, ZnO NPs exhibited significant antioxidant activity against scavenging DPPH free radicals. The current investigation demonstrated green engineering method for the synthesis of multifunctional ZnO NPs with interesting morphologies using neem extract.
authors.affiliation: Department of Electronics, Tumkur University, Tumkur 572 103, India.
authors.forename: H R
authors.initials: HR
authors.lastname: Madan
authors.affiliation: Dayananda Sagar University, Shavige Malleshwara Hills, Kumaraswamy layout, Bangalore 560078, Karnataka, India.
authors.forename: S C
authors.initials: SC
authors.lastname: Sharma
authors.affiliation: Department of Studies & Research in Chemistry, Tumkur University, Tumkur 572 103, India.
authors.lastname: Udayabhanu
authors.affiliation: Department of Studies & Research in Chemistry, Tumkur University, Tumkur 572 103, India.
authors.forename: D
authors.initials: D
authors.lastname: Suresh
authors.affiliation: Department of Physics, Lal Bahadur Shastry Government First Grade College, Bangalore 560 032, India. Electronic address: vidyays.phy@gmail.com.
authors.forename: Y S
authors.initials: YS
authors.lastname: Vidya
authors.affiliation: Prof. C.N.R. Rao Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India. Electronic address: bhushanvlc@gmail.com.
authors.forename: H
authors.initials: H
authors.lastname: Nagabhushana
authors.affiliation: Department of Studies and Research in Environmental Science, Tumkur University, Tumkur 572 103, India.
authors.forename: H
authors.initials: H
authors.lastname: Rajanaik
authors.affiliation: Department of Chemistry, Dayananda Sagar College of Engineering, Shavige Malleshwara Hills, Kumaraswamy layout, Bangalore 560078, Karnataka, India. Electronic address: ananth.che@gmail.com.
authors.forename: K S
authors.initials: KS
authors.lastname: Anantharaju
authors.affiliation: Department of Science, East West Institute of Technology, Bangalore 560 091, India.
authors.forename: S C
authors.initials: SC
authors.lastname: Prashantha
authors.affiliation: Dr. P. Sadananda Maiya Center for Food Science Research, 4th Block, Jayanagara, Bangalore 560 011, India.
authors.forename: P
authors.initials: P
authors.lastname: Sadananda Maiya
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D002384:Catalysis; D021902:Enterobacter aerogenes / Q000187:drug effects; D004756:Enterobacteriaceae Infections / Q000188:drug therapy; D055772:Green Chemistry Technology / Q000379:methods; D006801:Humans; D049408:Luminescent Agents / Q000737:chemistry* / Q000494:pharmacology; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D013203:Staphylococcal Infections / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000187:drug effects; D014466:Ultraviolet Rays; D015034:Zinc Oxide / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D049408:Luminescent Agents; D015034:Zinc Oxide
keywords: Rietveld analysis; SEM; TEM; XPS; ZnO nanostructures