Hierarchical hybrid nanostructures of Sn3O4 on N doped TiO2 nanotubes with enhanced photocatalytic performance

Abstract

Semiconductor nanostructures with photocatalytic activity have many potential applications including remediation of environmental pollutants and photocatalytic hydrogen evolution. An effective way of promoting photocatalytic activity is by creating heterogeneous photocatalysts. In this paper, a hybrid nanostructured photocatalyst with desired three-dimensional (3D) nanoarchitecture by assembling Sn₃O₄ nanosheets on N-doped TiO₂ nanotubes has been constructed with enhanced broad spectrum photocatalytic properties, which can harness UV and visible light to decompose organic contaminants in aqueous solutions and split water to hydrogen. Photocatalytic tests showed that the Sn₃O₄/N-TiO₂ hierarchical hybrid nanostructures possessed a much higher degradation rate of methyl orange and hydrogen evolution rate than that of the unmodified TiO₂ nanotubes, N-TiO₂ nanotubes, Sn₃O₄ nanosheets and Sn₃O₄/TiO₂ hybrid nanostructures. The mechanism related to the enhancement of the photocatalytic activity was discussed. Deposition of Sn₃O₄ nanosheets onto N-TiO₂ nanotubes resulted in a dramatic increase in light-induced generation of hydroxyl radicals, superoxides and singlet oxygen, and the production of holes and electrons. This work is the first instance of combining Sn₃O₄ with N-TiO₂, the Sn₃O₄/N-TiO₂ hierarchical hybrid nanostructures show good photocatalytic performance. This study is potentially applicable to a range of 3D hybrid nanostructures with promising applications in photocatalysis and relevant areas.