Photocatalytic degradation of textile dye X-3B using polyoxometalate-TiO2 hybrid materials

Titanium dioxide functionalized with Keggin type polyoxometalate (POMs) [X(n+)W(12)O(40)]((8-n)-) (XW(12); X(n+)=P(5+), Si(4+), Ge(4+)) were prepared by sol-gel method. The Keggin structure and dispersion state of POMs were monitored by FT-IR and XRD. The composites showed higher photocatalytic activity than pure TiO(2), pure POMs or mechanical mixture of TiO(2) and POMs for X-3B degradation. Among the three POMs-TiO(2) hybrid materials, the reactivity was: PW(12)>SiW(12)>GeW(12). With different loading weights for the same POMs, the reactivity followed the order: 30wt.%>15wt.%>45wt.%.