Enhanced photocatalytic capability of zinc ferrite nanotube arrays decorated with gold nanoparticles for visible light-driven photodegradation of rhodamine B

One-dimensional nanostructures grown on substrates are favored for photocatalytic reactions because of their large specific surface areas and well-defined transport paths for charge carriers. In the present paper, zinc ferrite nanotube arrays are synthesized on indium-tin-oxide-glass substrates, and their photocatalytic capabilities are evaluated by degrading an aqueous solution of rhodamine B (RhB) under visible light irradiation. The photocatalytic performance of pure zinc ferrite nanotube arrays is unsatisfactory. To improve their photocatalytic abilities, the surfaces of zinc ferrite nanotube arrays are decorated with Au nanoparticles, significantly enhancing their photocatalytic capabilities for RhB degradation. The drastic improvement in the photocatalytic degradation ability is attributed to the effective separation of photogenerated electron-hole pairs in the Au-decorated zinc ferrite hybrid nanostructure, which facilitates the generation of oxidizing free radicals (i.e., O (2) (aEuro cent) - and OH center dot) for RhB degradation.