Incorporation of Sn2+ Into Titanic Acid Nanotubes and Investigation of Their Visible-Light-Responsive Photocatalytic Activity

Titanate nanotubes have attracted much attention because of their large surface areas, strong ion-exchange capability, and perfect one-dimensional (1D) structure in photocatalysis, solar cells, sensors, and photoelectrochemistry. To expand their optical absorption, two kinds of Sn2+-incorporated titanic acid nanotubes (STAN) were prepared by an ion-exchange method in two different solvents (HCl solution/dehydrated methanol) at room temperature. After incorporation, STAN showed a strong visible light absorption, while their 1D morphology and orthorhombic structure were preserved. The physicochemical properties of the two kinds of STAN were compared in detail. The STAN obtained in methanol exhibit a larger Brunauer-Emmett-Teller (BET) surface areas and a higher photocatalytic activity for RhB degradation under visible light (lambda >= 420 nm).