Synthesis and physicochemical characterization of a ZnO-Chitosan hybrid-biocomposite used as an environmentally friendly photocatalyst under UV-A and visible light irradiations

• Tipo: Artigo em Revista Científica Internacional
• Data: 2020

Autores

Aadnan, I (Autor) Outra; Zegaoui, O (Autor) Outra; Daou, I (Autor) Outra; Joaquim C G E Esteves da Silva (Autor) FCUP

Revista

Título: Journal of Environmental Chemical Engineering

Vol. 8 Nº 104464

ISSN: 2213-3437

Editora: Elsevier

Indexação

ISI Web of Knowledge - 9 Citações

Outras Informações

ID Authenticus: P-00S-V3Y

DOI: 10.1016/j.jece.2020.104260

Abstract (EN): In this investigation, hybrid-biocomposites "ZnO-Chitosan" were synthesized using a chitosan biomaterial and various amounts of ZnO particles (7 and 93 wt percent). The chitosan was obtained from the exoskeletons of shrimp shells, which were collected from the fishmongers in Meknes city (Morocco). Several techniques including X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal analysis and thermogravimetric analysis, diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy coupled with energy dispersive spectroscopy were used for the characterization of the synthesized hybrid-biocomposites. The obtained experimental results showed the existence of a strong interaction between Zn-2(+), and the amino and hydroxyl groups of chitosan only for the hybrid-biocomposite containing 7 wt percent of ZnO. This suggests that the structure of this sample is probably formed via a complexation between Zn-2(+) ions which are linked to -NH2, -OH groups of chitosan, and H2O molecules. The photocatalytic activity of the asprepared hybrid-biomaterials was then evaluated by measuring the degradation efficiency of methyl orange (MO) and paranitrophenol (pNP) under both UV-A and visible light irradiation. The obtained results indicated that the photocatalytic performance was significantly improved by adding an optimum amount of ZnO (7 wt %) to the chitosan biomaterial, and suggested that the photocatalytic activity depended closely on the ZnO weight percent. The role of the active species (electrons, holes and hydroxyl radicals) in the photocatalytic process has been studied and the probable degradation mechanisms of MO and pNP under both UV-A and visible light illuminations were proposed.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 13