Characterizations of Ag doped ZnO particles via flame pyrolysis method for degradation of methylene blue

Abstract

Flame pyrolysis is widely used for the fabrication of particles because of great crystallinity and fine size distribution of the products. In this research, ZnO-Ag particle materials have been favourably made by flame pyrolysis. The impacts of Ag loading varying from 0 to 20 wt% on the photocatalytic activity of ZnO-Ag particle under ultraviolet (UV) and sunlight irradiations were studied. ZnO-Ag particles were fabricated based on zinc acetate dihydrate (Zn(CH3COO)2.2H2O) 0.1 M and silver nitrate (AgNO3) as a precursor inside a flame reactor. Crystallinity and morphology of ZnO-Ag particles were identified by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. SEM analysis showed that the particles had irregular sphere-like shapes. The XRD patterns showed that the produced ZnO had a wurtzite structure with different crystallite sizes. XRD analysis also confirmed the existence of Ag particles in ZnO-Ag particles after the addition of Ag greater or equal to 5 wt%. The existence of Ag was indicated by the appearance of the XRD peak at 38.1°. The peak at 38.1° increased with the increase of Ag loading. Finally, the photocatalytic activity was evaluated by estimating the degradation of methylene blue aqueous solution under UV and sunlight irradiations. It noted that the most excellent photocatalytic performance was achieved at 5 wt% Ag loading for both irradiations.

Effect of Gas Flowrate on the Properties and Photocatalytic Activity of ZnO-Ag Nanocomposite Materials Prepared by Flame Pyrolysis

“…When the XRD image was adjusted by JCPDS (Joint Committee on Powder Diffraction Standards), the ZnO particles obtained were in the form of hexagonal wurtzite (w-ZnO) [20]. Where in a previous study (Wang et al, 2012) it was stated that w-ZnO is the most stable structure and is most often found at ambient or normal pressure and a stable thermodynamic phase [14].…”

“…In addition, the product has high crystallinity and narrow size distribution. Product properties, such as: crystal size, crystal phase, degree of aggregation and agglomeration, surface area, and porosity can also be controlled by adjusting the flame conditions [14]. To the best of our knowledge, the effect of the flowrate on the flame process on the formation of ZnO-Ag composite materials has not been explored.…”