Hierarchically Structured Porous SnO2/TiO2 Materials with Design Controllable Phases and Enhanced Photocatalytic Activity

Abstract

To increase the photogenerated carrier separation and reduce the electron-hole recombination process for photocatalysts performance. In this article, hierarchically macroporous structured TiO₂/SnO₂ materials with controllable composition and phases have been successfully synthesized by using a typical process. This method involves several sequential preparation steps: (1) preparation of core-shell structure SnO₂/PS submicrospheres by hydrothermal method; (2) preparation of TiO₂/SnO₂/PS submicrospheres by assembling amorphous TiO₂ on surface of SnO₂/PS submicrospheres; (3) direct calcination of TiO₂/SnO₂/PS submicrospheres to eventually produce hierarchically structured TiO₂/SnO₂ materials with pores-in-pores. With rutile phases TiO₂, TiO₂/SnO₂ macroporous materials show significantly enhanced catalytic activity when used as photocatalysts for the degradation of Rhodamine B under UV irradiation. The photodegradation ratio of Rhodamine B was 96% for 25 min.