LAUSR

Three dimensional porous WO3 was fabricated by a novel freeze-drying method using a polyvinyl alcohol (PVA)/phosphotungstic acid (H3PW12O40) aqueous solution as the precursor followed by calcination. Results revealed that WO3 interconnected porous structures have channels of 3–10 µm and wall thicknesses of about 0.68 µm. Interestingly, the morphology and porous structure of WO3 samples can be well controlled by the amount of PVA and calcination temperature. To further demonstrate their potential application in photocatalysis, their photocatalytic activities for the photodegradation of Rhodamine B under visible light irradiation were investigated. It was found that the highest photocatalytic activity was obtained by using the WO3 porous sample which prepared by fixing the addition amount of PVA at 7.5% (relative to solvent) and the calcination temperature at 800 °C. The enhanced photocatalytic performance of WO3 can be attributed to the combined effects of increased surface area, the interconnected macroporous as well as the enhanced crystal quality.