title: Zinc(II) phthalocyanines immobilized in mesoporous silica Al-MCM-41 and their applications in photocatalytic degradation of pesticides.
abstract: In the present study the authors investigated a set of three new zinc(II) phthalocyanines (zinc(II) tetranitrophthalocyanine (ZnTNPc), zinc(II) tetra(phenyloxy)phthalocyanine (ZnTPhOPc) and the tetraiodide salt of zinc(II)tetra(N,N,N-trimethylaminoethyloxy) phthalocyaninate (ZnTTMAEOPcI)) immobilized into Al-MCM-41 prepared via ship-in-a-bottle methodology. The samples were fully characterized by diffuse reflectance-UV-vis spectroscopy (DRS-UV-vis), luminescence, thermogravimetric analysis (TG/DSC), N(2) adsorption techniques and elemental analysis. A comparative study was made on the photocatalytic performance upon irradiation within the wavelength range 320-460nm of these three systems in the degradation of pesticides fenamiphos and pentachlorophenol. ZnTNPc@Al-MCM-41 and ZnTTMAEOPcI@Al-MCM-41 were found to be the most active systems, with the best performance observed with the immobilized cationic phthalocyanine, ZnTTMAEOPcI@Al-MCM-41. This system showed high activity even after three photocatalytic cycles. LC-MS product characterization and mechanistic studies indicate that singlet oxygen ((1)O(2)), produced by excitation of these immobilized photosensitizers, is a key intermediate in the photocatalytic degradation of both pesticides.
authors: Departamento de Química, Universidade de Coimbra, Coimbra, Portugal.
authors: M
authors: M
authors: Silva
authors: M J F
authors: MJ
authors: Calvete
authors: N P F
authors: NP
authors: Gonçalves
authors: H D
authors: HD
authors: Burrows
authors: M
authors: M
authors: Sarakha
authors: A
authors: A
authors: Fernandes
authors: M F
authors: MF
authors: Ribeiro
authors: M E
authors: ME
authors: Azenha
authors: M M
authors: MM
authors: Pereira
mesh_terms: D002384:Catalysis; D007211:Indoles / Q000737:chemistry* / Q000528:radiation effects; D054833:Isoindoles; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000528:radiation effects; D010416:Pentachlorophenol / Q000737:chemistry / Q000528:radiation effects; D010575:Pesticides / Q000737:chemistry* / Q000528:radiation effects; D010782:Photolysis; D012822:Silicon Dioxide / Q000737:chemistry* / Q000528:radiation effects; D014466:Ultraviolet Rays; D015032:Zinc / Q000737:chemistry*
chemical_list: D007211:Indoles; D054833:Isoindoles; C509968:MCM-41; D009943:Organophosphorus Compounds; D010575:Pesticides; D012822:Silicon Dioxide; D010416:Pentachlorophenol; C002698:fenamiphos; D015032:Zinc; C013647:phthalocyanine