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

Abstract

It is well known that adding the appropriate amount of Ag to semiconductor materials can enhance photocatalytic performance. In our previous study, the addition of Ag nanoparticles to ZnO enhanced the photocatalytic activity. The best photocatalytic performance was obtained when Ag content was 5 wt%. However, the effect of a carrier gas flow rate has not been investigated. The objective of this study is to investigate the effect of carrier gas flow rate on the morphology of the ZnO-Ag nanocomposites as well as the photocatalytic activity of the produced nanocomposites. ZnO-Ag nanocomposite was fabricated by a one-step process using flame pyrolysis and the produced nanocomposites were characterized by a scanning electron microscope (SEM) and X-Ray Diffraction (XRD) analysis. The photocatalytic performance was evaluated by measuring the degradation of methylene blue under UV light irradiation. SEM images indicated that the morphology of ZnO-Ag nanocomposites has a spherical shape with a particle diameter of around 65 nm. Moreover, increasing the flow rate will increase the particle size of the produced nanocomposites. The photocatalytic test was determined based on the rate constant of MB degradation efficiency under UV light irradiation, where the photocatalytic activity decreased when the carrier gas increased. Finally, the produced nanocomposites were also tested several times (recycling test), where photocatalytic performance showed that the degradation value of methylene blue for each recycle did not vary much with the variable before being recycled.