3D Au-decorated BiMoO6 nanosheet/TiO2 nanotube array heterostructure with enhanced UV and visible-light photocatalytic activity

To develop an efficient visible-light-driven photocatalyst electrode for environmental remediation, a novel ternary nanocomposite of an Au-decorated Bi2MoO6 nanosheet/TiO2 nanotube array (NTA) heterojunction was successfully fabricated for the first time via a facile solvothermal method combined with mussel-inspired functional modification of electrochemical polymerization of dopamine. In this strategy, the Au3+ ions were in situ reduced to metallic Au nanoparticles (NPs) due to the abundant catechol and amine groups from the polydopamine layer. The resulting Au/Bi2MoO6@TiO2 NTAs heterostructural electrode greatly exhibits enhanced electrochemical properties and excellent photocatalytic performance for the photo-degradation of organic dyes (methylene blue) and benzene series compounds (BSCs) under UV and visible-light irradiation. The improved photocatalytic performance is mainly ascribed to the surface plasmon resonance (SPR) effect induced by Au NPs and the cooperative electronic capture properties of Au NPs, Bi2MoO6 nanosheets and TiO2 NTAs, resulting in the extended absorption in the visible-light region and effectively preventing the recombination of electron-hole pairs and transfer of the electrons which participate in the photodegradation process. Moreover, the stability of the photocatalysts and mechanisms for the sustainable photocatalysis are discussed.