3D Carambola-Like CuO/TiO₂ Nanotube Heterostructures via Low-Temperature Solution Process for Photocatalytic Activity

CuO/TiO₂ heterostructures have been synthesized via a facile low-temperature solution method. The resultant heterostructures present a three-dimensional hierarchical morphology of carambola-like CuO integrated with TiO₂ nanotubes (NTs), confirmed by means of SEM, TEM, EDS, XRD and XPS. And time-dependent evolutions of morphology show that the CuO grow from the initial leaf-shaped nanosheets and eventually form carambola-like structures. The UV/Vis absorption spectrum indicates that the carambola-like CuO/TiO₂ NTs have strong absorption in the UV light region as well as in the visible light region. The study on evaluating photocatalytic activity indicates that the carambola-like CuO/TiO₂ NTs can degrade 40 % of Rhodamine B, exhibiting enhanced photocatalytic activity compared with TiO₂ NTs. Moreover, the photocatalytic mechanism of the carambola-like CuO/TiO₂ NT heterostructures is expounded.