Photocatalytic degradation of acid blue 74 in water using Ag–Ag2O–Zno nanostuctures anchored on graphene oxide

• Novel Ag–Ag2O–ZnO and Ag–Ag2O–ZnO- graphene oxide nanostructures were synthesized.
• The composites were applied in the photocatalytic degradation of acid blue 74 dye.
• Ag, Ag2O and graphene oxide improved the visible photocatalytic properties of ZnO.
• Percentage dye removal: ZnO (75%), Ag–Ag2O–ZnO (85%) and Ag–Ag2O–ZnO/GO (90%).

Water pollution due to industrial effluents from industries which utilize dyes in the manufacturing of their products has serious implications on aquatic lives and the general environment. Thus, there is need for the removal of dyes from wastewater before being discharged into the environment. In this study, a nanocomposite consisting of silver, silver oxide (Ag2O), zinc oxide (ZnO) and graphene oxide (GO) was synthesized, characterized and photocatalytically applied in the degradation (and possibly mineralization) of organic pollutants in water treatment process. The Ag–Ag2O–ZnO nanostructure was synthesized by a co-precipitation method and calcined at 400 °C. It was functionalized using 3-aminopropyl triethoxysilane and further anchored on carboxylated graphene oxide via the formation of an amide bond to give the Ag–Ag2O–ZnO/GO nanocomposite. The prepared nanocomposite was characterized by UV–Vis diffuse reflectance spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electronic microscopy (SEM), energy dispersive X-ray spectrometry (EDX), Fourier transformed infrared spectroscopy (FTIR), and Raman spectroscopy. The applicability of Ag–Ag2O–ZnO/GO nanocomposite as a photocatalyst was investigated in the photocatalytic degradation of acid blue 74 dye under visible light irradiation in synthetic wastewater containing the dye. The results indicated that Ag–Ag2O–ZnO/GO nanocomposite has a higher photocatalytic activity (90% removal) compared to Ag–Ag2O–ZnO (85% removal) and ZnO (75% removal) respectively and thus lends itself to application in water treatment, where the removal of organics is very important.

Visible photocatalytic activity mechanism and spectrophotometric degradation profile of acid blue 74 dye on Ag–Ag2O–ZnO/GO nanocomposite.Figure optionsDownload as PowerPoint slide