Hydrothermally synthesized Na2Ti3O7 nanotube-V2O5 heterostructures with improved visible photocatalytic degradation and hydrogen evolution - Its photocorrosion suppression

There is still a need to prepare heterostructure photocatalysts with high activity and recyclability but without using precious metals to reduce the cost of photocatalysts. Thus, a facile and simple method for the synthesis of a Na2Ti3O7 nanotube-V2O5 heterostructure photocatalyst via hydrothermal synthesis is reported herein. The chemical composition, morphology, and structural features of the photocatalyst were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N-2 adsorption-desorption specific surface area analysis (BET), and diffuse reflectance absorption (DRS) methods. It was observed that the specific surface area of the Na2Ti3O7 nanotube-V2O5 heterostructure photocatalyst increased with the incorporation of V2O5. The Na2Ti3O7 nanotube-V2O5 heterostructure photocatalyst was then used for the removal of rhodamine B (RhB) under simulated solar light irradiation. The Na2Ti3O7 nanotube-V2O5 heterostructure photocatalyst revealed excellent photocatalytic activity and photodegradation kinetics as compared to pristine Na2Ti3O7 nanotubes and V2O5 photocatalysts. Furthermore, both the photoactivity and long-term stability of the Na2Ti3O7 nanotube-V2O5 heterostructure photocatalyst were superior to those of the pristine Na2Ti3O7 nanotubes and V2O5 photocatalysts. The excellent photocatalytic performance of the Na2Ti3O7 nanotube-V2O5 heterostructure photocatalyst can be ascribed to its high specific surface area (283.71 m(2)g(-1)), mesoporous structure, highly dispersed V2O5 nanoparticles, and hindrance of electron-hole pair recombination of Na2Ti3O7 due to the V2O5 incorporation, which is proven by the photoelectrochemical results, including photocurrent and electron impendence spectroscopy results. In addition, during the study of photocatalytic hydrogen evolution, the hydrogen yield of the Na2Ti3O7/V2O5 nanocomposite was 1.83 times that of pristine Na2Ti3O7, which also exhibited excellent photocatalytic activity. (C) 2018 Elsevier B.V. All rights reserved.