Titanium dioxide composite films for enhanced photocatalytic activity

In order to extend light response of TiO2 into the visible region and enhance its photocatalytic activity, W and S codoped TiO2–SiO2–ZnO composite film was successfully prepared. The Brunauer–Emmett–Teller (BET) results showed that the surface area of the modified TiO2 was 424.5 m2 g−1, while that of the pure TiO2 was 103.4 m2 g−1. The high-resolution field emission scanning electron microscopy (FE-SEM) results revealed that the surface of the modified TiO2 film was more uniform and smooth with smaller particles compared to pure TiO2 film. The diffuse reflectance measurements exhibited that the modified TiO2 film had obvious red-shift. The photoluminescence (PL) analysis indicated that the electron–hole recombination rate was effectively inhibited in the modified TiO2 systems. The photocatalytic activities of the TiO2 films were evaluated by the photocatalytic decomposition of organic dyes in aqueous solution. Compared with pure TiO2 film, the modified TiO2 film exhibited excellent photocatalytic activity.