Solution Volume Effect of Photodegradation by 1-D WO3 Nanorods via Microwave-Assisted Solvothermal Heating Under the UV Irradiation

Abstract

The 1-D nanorods of WO₃ was synthesized by solvothermal-assisted microwave system. These nanorods was employed as photocatalysts in the photodecomposition reaction of methyl orange under the UV light. The powder was characterized by XRD, SEM and TEM. UV-Visible diffuse reflection spectroscopy was used to measure the degradation efficiency. Different total solution volumes ranging between 400-1000 mL were responsible for the change in organic pollutants' photocatalysis efficiency. Furthermore, the effect of changing the concentration of methyl orange from 100-400 ppm was also studied in the context of large solution volume. The results suggested that apparent pseudo-first-order homogeneous reaction model can be used for describing the kinetic behaviour and higher photocatalytic activities induced through large solution volumes; k_app is 5.34 × 10^-2 min^-1 for 250 ppm catalyst at 800 mL methyl orange solution. In addition, the photocatalytic activity of WO₃ nanorods was 3.6 times higher than that of commercial P25 TiO₂ powder.