Facile synthesis and visible photocatalytic activity of single-crystal TiO2/PbTiO3 heterostructured nanofiber composites

Abstract

Single-crystal TiO₂/PbTiO₃ nanofiber composites were prepared by a simple hydrothermal synthesis and annealing treatment at 650 °C, where pre-perovskite (PP) PbTiO₃ (PTO) and tetrabutyl titanate (TBOT) were used as precursors. In the composites, anatase TiO₂ nanorods grew on the surface of tetragonal perovskite (TP) PTO nanofibers and formed sharp TiO₂/PbTiO₃ interfaces, leading to single-crystal heterostructures. The as-synthesized heterostructured nanofiber composites exhibited excellent photocatalytic activity for degradation of methylene blue (MB) under visible light irradiation (λ > 400 nm). Especially, the composites TiO₂/PbTiO₃ TBOT: 0.4 mL showed the highest photocatalytic activity, and the degradation rate of MB was 0.02392 min⁻¹. Such photocatalytic activity of the heterostructured nanofiber composites was supposedly attributed to the large-scale formation of the sharp interfaces, which could be critical for the photogenerated charge carrier separation and its transfer from the PTO phase to TiO₂. It is suggested that the obtained heterostructured nanofiber composites TiO₂/PbTiO₃ can be exploited as an alternative visible-light-driven photocatalyst.