Influence of microwave-assisted hydrothermal treatment time on the crystallinity, morphology and optical properties of ZnWO4 nanoparticles: Photocatalytic activity

• Autor(a) principal: Andrade Neto, Nivaldo Ferreira da
• Data de Publicação: 2020
• Outros Autores: Nunes, T. B. O., Li, Máximo Siu, Silva, Elson Longo da, Delmonte, Maurício Roberto Bomio, Motta, Fabiana Villela da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/37981
• topic: Microwave-assisted hydrothermal method; ZnWO4 nanoparticles; Photocatalytic properties; Anionic and cationic dyes

In this work, zinc tungstate (ZnWO4) nanoparticles were obtained by microwave-assisted hydrothermal method at 140 °C and 2 atm. The hydrothermal treatment time was varied at 0, 5, 10, 30, 60 and 120 min. The nano- particles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scan- ning electron microscopy (SEM), transmission electron microscope (TEM), high-resolution transmission electron microscope (HRTEM), X-ray fluorescence (FRX), nitrogen adsorption by Brunauer-Emmett-Teller method (BET), UV–Visible spectroscopy (UV–Vis) and Photoluminescence (PL) properties. The adsorptive and photocatalytic properties were estimated against methylene blue (MB - cationic) and methyl orange (MO - anionic) dyes. The diffractograms show that the larger hydrothermal treatment time, anhigher the powders crystallinity. The BET and SEM analysis indicate that the increase in hydrothermal time does not interfere significantly in nanoparticles size but reduces their porosity. The change in the surface area is consistent with the adsorption tests, where the increase of the hydrothermal treatment time reduces the adsorption against the MB and MO dyes. However, increasing the hydrothermal treatment time provides an increase in photocatalytic activity