Synthesis of scaly Sn3O4/TiO2 nanobelt heterostructures for enhanced UV-visible light photocatalytic activity

Abstract

A novel scaly Sn₃O₄/TiO₂ nanobelt heterostructured photocatalyst was fabricated via a facile hydrothermal route. The scaly Sn₃O₄ nanoflakes can be synthesized in situ and assembled on surface coarsened TiO₂ nanobelts through a hydrothermal process. The morphology and distribution of Sn₃O₄ nanoflakes can be well-controlled by simply tuning the Sn/Ti molar ratio of the reactants. Compared with single phase nanostructures of Sn₃O₄ and TiO₂, the scaly hybrid nanobelts exhibited markedly enhanced photoelectrochemical (PEC) response, which caused higher photocatalytic hydrogen evolution even without the assistance of Pt as a co-catalyst, and enhanced the degradation ability of organic pollutants under both UV and visible light irradiation. In addition to the increased exposure of active facets and broad light absorption, the outstanding performance is ascribed to the matching energy band structure between Sn₃O₄ and TiO₂ at the two sides of the heterostructure, which efficiently reduces the recombination of photo-excited electron–hole pairs and prolongs the lifetime of charge carriers. Both photocatalytic assessment and PEC tests revealed that Sn₃O₄/TiO₂ heterostructures with a molar ratio of Sn/Ti of 2/1 exhibited the highest photocatalytic activity. This study provides a facile and low-cost method for the large scale production of Sn₃O₄ based materials in various applications.