Effect of Ag content in ZnO-Ag nanocomposites prepared by spray pyrolysis method for degradation of textile dye waste

In this study, ZnO-Ag nanocomposites with different Ag loadings have been successfully synthesized by spray pyrolysis using nitrogen as a carrier gas. The Ag loading with various concentrations from 0 to 10 %wt was doped to the ZnO particles. The performance of products, ZnO-Ag nanocomposites, was subsequently tested by measuring the photocatalytic degradation of organic waste from the textile dye. Morphology, crystallite size and crystalline phase, surface area and functional group of hydroxyl of the produced nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. SEM images indicated that the average particle size of the nanocomposite measured by ImageJ software increased with increasing Ag loading. The average size of nanocomposite with Ag loading at 0, 1, 5, and 10 %wt were 784, 850, 856 and 954 nm, respectively. The XRD results detected the existence of Ag in ZnO-Ag nanocomposite. However, the addition of Ag in the nanocomposite did not alter the crystallite size significantly, where the crystallite size was found approximately around 18 to 57 nm. Moreover, BET analysis showed the increase of specific surface area with increasing Ag content in exception for Ag content at 5 %wt. Finally, ultraviolet (UV) light was used as an irradiation source to evaluate the performance of photocatalytic degradation of textile-dye-waste from the textile industry in Gresik-Indonesia. The results showed that Ag loading at 5 %wt produced the highest degradation efficiency among the other concentrations including the pristine ZnO. This research resulted in a simple and effective route for fabricating ZnO-Ag nanocomposite; therefore, it can be considered as a potential candidate for the direct application in degradation of textile-dye-waste.