• Baia, Monica

Abstract

<jats:p>WO<jats:sub>3</jats:sub>-TiO<jats:sub>2</jats:sub> composite materials were obtained using commercial titania (Evonik Aeroxide P25) and hydrothermally crystallized WO<jats:sub>3</jats:sub>. Different ratios of TiO<jats:sub>2</jats:sub>/WO<jats:sub>3</jats:sub> were investigated, starting at 1 wt.% of WO<jats:sub>3</jats:sub> to 50 wt.%. The morphology of WO<jats:sub>3</jats:sub> was of the star-like type, and its structure is basically composed of monoclinic crystalline phase. All spectroscopic characteristics of the composites and their derived data (band-gap energy value, light absorption threshold, and IR specific bands) directly varied with the increase of the WO<jats:sub>3</jats:sub> content. However, the oxalic acid photodegradation achieved under UV light reached the highest yield for 24 wt.% WO<jats:sub>3</jats:sub> content, a result that was attributed to the charge separation efficiency and the surface hydrophilicity. The latter mentioned reason points out the crucial importance of the surface quality of the investigated structure in photocatalytic tests.</jats:p>

Topics

• impedance spectroscopy
• morphology
• surface
• crystalline phase
• semiconductor
• composite