Photocatalytic degradation of nitrobenzene by gold nanoparticles decorated polyoxometalate immobilized TiO2 nanotubes

•Au-NPs were deposited on the surface of polyoxometalate immobilized TiO2 nanotubes.•HPW plays the role of multifunctional photocatalyst linker molecule.•It shows high photocatalytic efficiency in nitrobenzene removal.•The photocatalytic performance enhanced 4.1-fold compared to TiO2 nanotube. In this study, the gold nanoparticles were deposited on the surface of tungstophosphoric acid immobilized TiO2 nanotubes, in which tungstophosphoric acid plays the roles of highly localized UV-switchable reducing agent and multifunctional photocatalyst linker molecule. The prepared novel nanocomposite was characterized with FTIR, XRD, EDX and TEM and showed high photocatalytic efficiency in nitrobenzene removal. The results demonstrated that by introducing of AuNPs, the photocatalytic performance significantly enhanced, where the photocatalytic rate of using Au/HPW/TiO2-NTs nanocomposites was 4.1-fold increase compared to TiO2 nanotubes. The photocatalytic mechanism was proposed.