title: Studies on visible light photocatalytic and antibacterial activities of nanostructured cobalt doped ZnO thin films prepared by sol-gel spin coating method.
abstract: Nanostructured cobalt doped ZnO thin films were deposited on glass substrate by sol-gel spin coating technique and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and UV-Vis spectroscopy. The XRD results showed that the thin films were well crystalline with hexagonal wurtzite structure. The results of EDAX and XPS revealed that Co was doped into ZnO structure. FESEM images revealed that the films possess granular morphology without any crack and confirm that Co doping decreases the grain size. UV-Vis transmission spectra show that the substitution of Co in ZnO leads to band gap narrowing. The Co doped ZnO films were found to exhibit improved photocatalytic activity for the degradation of methylene blue dye under visible light in comparison with the undoped ZnO film. The decrease in grain size and extending light absorption towards the visible region by Co doping in ZnO film contribute equally to the improved photocatalytic activity. The bactericidal efficiency of Co doped ZnO films were investigated against a Gram negative (Escherichia coli) and a Gram positive (Staphylococcus aureus) bacteria. The optical density (OD) measurement showed better bactericidal activity at higher level of Co doping in ZnO.
authors.affiliation: Department of Physics, Quaid-e-Millath Govt. College for Women, Chennai 600 002, India; Department of Physics, Presidency College, Chennai 600 005, India.
authors.forename: G
authors.initials: G
authors.lastname: Poongodi
authors.affiliation: Department of Physics, Thiruvalluvar College of Engineering and Technology, Vandavasi 604505, India.
authors.forename: P
authors.initials: P
authors.lastname: Anandan
authors.affiliation: Department of Physics, Presidency College, Chennai 600 005, India. Electronic address: mohan66@hotmail.com.
authors.forename: R Mohan
authors.initials: RM
authors.lastname: Kumar
authors.affiliation: Centre for Nanoscience and Technology, Anna University, Chennai 600 025, India.
authors.forename: R
authors.initials: R
authors.lastname: Jayavel
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry* / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects; D004927:Escherichia coli Infections / Q000517:prevention & control; D006801:Humans; D008027:Light; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D044367:Phase Transition; D013052:Spectrometry, X-Ray Emission; D013203:Staphylococcal Infections / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000187:drug effects; D015034:Zinc Oxide / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D003035:Cobalt; D015034:Zinc Oxide
keywords: Antibacterial activity; Cobalt doped ZnO; FESEM; Photocatalytic activity; Sol–gel spin coating method; Thin film