TiO2 nanotube arrays co-loaded with Au nanoparticles and reduced graphene oxide: Facile synthesis and promising photocatalytic application

Graphical abstract: Methyl orange (MO) can be efficiently removed through photodegradation process using a novel photocatalyst, Au nanoparticles and reduced graphene oxide co-loaded TiO2 nanotube arrays. Highlights: •The photocatalyst is prepared by an one-step constant potential deposition process. •The ternary photocatalyst shows effective separation of photogenerated charges. •The photocatalyst displays almost 100% photocatalytic removal of methyl orange. •The photocatalyst is easily recovered with excellent cycling stability. -- Abstract: Au nanoparticles and reduced graphene oxide co-loaded TiO2 nanotube arrays (Au/RGO–TiO2 NTs) were prepared through a simple one-step constant-potential electrolysis of chloroauric acid and graphene oxide on TiO2 NTs. Compared with Au–TiO2 NTs, RGO–TiO2 NTs and un-modified TiO2 NTs, the Au/RGO–TiO2 NTs exhibited high efficiency in photocatalytic degradation of methyl orange (MO) under simulated solar light irradiation. The highly efficient photocatalytic activity is associated with broad absorption in the visible light region, increased photoinduced charge separation through transferring photogenerated electrons from TiO2 NTs to both Au and RGO, as well as the strong adsorption ability of RGO to MO molecules. Moreover, the Au/RGO–TiO2 NTs has an excellent stability. This work provides an insight into designing and synthesizing new TiO2 NTs-based hybrid materials for effective visible light-activated photocatalysis