Navegando por Autor "Miranda, Liany D. L."
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Item Preparation of calcined hydrotalcite/TiO2-Ag composite and enhanced photocatalytic properties(Ceramics International, 2017-02-01) Almeida, Marciano F. de; Bellato, Carlos R.; Miranda, Liany D. L.; Milagres, Jaderson L.A series of calcined hydrotalcite/TiO2-Ag (HTC/TiO2-Ag) composites with different silver (Ag) contents were successfully prepared and investigated as a catalyst for the photodegradation of phenol using UV–vis light (λ>300 nm). The Ag nanoparticles were deposited on the surface of TiO2 (TiO2-Ag) through photodeposition method. The TiO2-Ag nanoparticles were supported on hydrotalcite (HT) by the co-precipitation method at variable pH (HT/TiO2-Ag), and then calcined at 500 °C to obtain the HTC/TiO2-Ag composites. The composites were characterized by inductively coupled plasma mass spectrometry (ICP-MS), N2 adsorption/desorption (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and diffuse reflectance spectra (DRS). Results show that there is an optimum silver ratio to obtain the highest photocatalytic performance in the HTC/TiO2-Ag photocatalyst which is 2 wt%, and is assigned as HTC/TiO2-Ag(2). The association of silver nanoparticles on TiO2 enhanced photocatalytic activity of the bare semiconductor composite. Only 56% of phenol was photodegraded when photodegradation was performed with HTC/TiO2, whereas ~100% was photodegraded using HTC/TiO2-Ag(2). The data gathered from the photocatalytic degradation of phenol were successfully fitted to Langmuir-Hinshelwood model, and can be described by pseudo-first order kinetics. The results showed the HTC/TiO2-Ag(2) as efficient photocatalyst, low cost, separable from solution by sedimentation, and reusable. The superior performance of HTC/TiO2-Ag(2) composite photocatalyst may be attributed to the synergic catalytic effect between silver and TiO2, dispersion of TiO2-Ag(2) nanoparticles supported on calcined hydrotalcite, and the calcined hydrotalcite like photocatalyst.Item Syntheses, characterization and antifungal activity of novel dimethylbis(N-R-sulfonyldithiocarbimato)stannate(IV) complexes(Elsevier Journal of Molecular Structure, 2017-02-05) Bomfim Filho, Lucius F. O.; Oliveira, Marcelo R. L.; Miranda, Liany D. L.; Vidigal, Antonio E. C.; Guilardi, Silvana; Souza, Rafael A. C.; Ellena, Javier; Ardisson, José D.; Zambolim, Laércio; Rubinger, Mayura M. M.Four new complexes of the general formula: Ph4P)2[Sn(CH3)2(RSO2NCS2)2], where Ph4P = tetraphenylphosphonium cation and R = CH3, (1), CH3CH2 (2), C6H5 (3), 4-FC6H4 (4), were prepared by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimates, K2(RSO2NCS2), and tetraphenylphosphonium chloride with dimethyltin dichloride. The compounds 1–4 were characterized by 1H, 13C and 119Sn NMR, 119Sn Mössbauer, vibrational spectroscopy and by elemental analyses of C, H, N and Sn. The crystal structure of 1 was determined by X-ray diffraction techniques. The in vitro antifungal activity of the tin(IV) complexes were evaluated against the fungi Rhizoctonia solani and Botrytis cinerea by the Poisoned food test. The new compounds showed comparable activities to the fungicides manzate and ziram.Item Syntheses, crystal structure, spectroscopic characterization and antifungal activity of new N-R-sulfonyldithiocarbimate metal complexes(Journal of Inorganic Biochemistry, 2009-07) Alves, Leandro C.; Rubinger, Mayura M. M.; Lindemann, Renata H.; Perpétuo, Genivaldo Júlio; Janczak, Jan; Miranda, Liany D. L.; Zambolim, Laércio; Oliveira, Marcelo R. L.Five new compounds with the general formula of (Bu4N)2[M(RSO2NCS2)2], where Bu4N = tetrabutylammonium cation, (M = Ni, R = 4-FC6H4) (1), (M = Zn, R = 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-IC6H4), (2), (3), (4) and (5), respectively, were obtained by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2NCS2K2) with nickel(II) chloride hexahydrate or zinc(II) acetate dihydrate in metanol:water 1:1. The elemental analyses and the IR data are consistent with the formation of the expected bis(dithiocarbimato)metal(II) complexes. The 1H and 13C NMR spectra showed the signals for the tetrabutylammonium cation and the dithiocarbimate moieties. The compounds 1, 2 and 5 were also characterized by X-ray diffraction techniques. The nickel(II) is coordinated by two N-4-fluorophenylsulphonyldithiocarbimato(2-) ligands forming a planar coordination. The zinc(II) exhibits distorted tetrahedral configuration in compounds 2 and 5 due to the chelation effect of two sulfur atoms of the N-R-sulfonyldithiocarbimate ligands. The antifungal activities of the compounds were tested in vitro against Colletotrichum gloeosporioides, an important fungus that causes the plant disease known as anthracnose in fruit trees. All the complexes were active.