Enhanced photocatalytic properties of mesoporous SnO2 induced by low concentration ZnO doping

Mesoporous SnO2 doped with a low concentration of ZnO (m-SnO2/ZnO), prepared through a hydrothermal method by using cetyltrimethylammonium bromide (CTAB) as a structure-directing agent, has been characterized by transmission electron microscopy, powder X-ray diffraction, and nitrogen adsorption-desorption technologies. It was found that doped m-SnO2 showed different properties compared with undoped mesoporous SnO2 (m-SnO2). The former not only had a larger Brunauer-Emmett-Teller (BET) surface area but also showed a more stable mesoporous structure against high-temperature sintering than did the latter. Furthermore, m-SnO2/ZnO exhibited a significant enhancement of photocurrent and photocatalytic capability toward degrading rhodamine B (RhB) compared to undoped mesoporous SnO2. The improvement of photocatalytic activity for m-SnO2/ZnO might be attributed to its higher specific surface area and enhanced charge separation that derive from the coupling of ZnO with SnO2.