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

Abstract

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 photo-degradation process. Moreover, the stability of the photocatalysts and mechanisms for the sustainable photocatalysis are discussed.