Facile hydrothermal synthesis of TiO2/Bi2WO6 hollow microsphere with enhanced visible-light photoactivity

Abstract

In this paper, novel TiO2/Bi2WO6 heterojunction photocatalysts with hollow microsphere structures were successfully fabricated by a one-pot glucose-assisted hydrothermal route followed by the calcination at 450°C. The photocatalytic activities of the as-prepared photocatalysts were evaluated on the degradation of rhodamine B (RhB) aqueous solution under visible light irradiation and the results indicated that the as-prepared TiO2/Bi2WO6 composite exhibited higher photocatalytic activity than bare TiO2 and Bi2WO6. In addition, the TiO2/Bi2WO6 composite with TiO2 loading of 20wt.% showed the highest photocatalytic activity and retained the high photocatalytic performance after four recycles for the photodegradation of RhB, confirming its stability and practical usability. The enhanced photocatalytic activity of TiO2/Bi2WO6 composite was attributed to well matched energy band positions of TiO2 and Bi2WO6, which facilitated the efficient separation of photogenerated electron–hole pairs and thereby led to the increasing photocatalytic activity. On the basis of calculated energy band positions, the results of photoluminescence (PL) and active species trapping experiments, the mechanism of the obviously enhanced photocatalytic performance was proposed.