Surface Plasmon Resonance-Enhanced Visible-NIR-Driven Photocatalytic and Photothermal Catalytic Performance by Ag/Mesoporous Black TiO2 Nanotube Heterojunctions.

Abstract

Ag/mesoporous black TiO2 nanotubes heterojunctions (Ag-MBTHs) were fabricated through a surface hydrogenation, wet-impregnation and photoreduction strategy. The as-prepared Ag-MBTHs possess a relatively high specific surface area of ≈85 m2 g-1 and an average pore size of ≈13.2 nm. The Ag-MBTHs with a narrow band gap of ≈2.63 eV extend the photoresponse from UV to the visible-light and near-infrared (NIR) region. They exhibit excellent visible-NIR-driven photothermal catalytic and photocatalytic performance for complete conversion of nitro aromatic compounds (100 %) and mineralization of highly toxic phenol (100 %). The enhancement can be attributed to the mesoporous hollow structures increasing the light multi-refraction, the Ti3+ in frameworks and the surface plasmon resonance (SPR) effect of plasmonic Ag nanoparticles favoring light-harvesting and spatial separation of photogenerated electron-hole pairs, which is confirmed by transient fluorescence. The fabrication of this SPR-enhanced visible-NIR-driven Ag-MBTHs catalyst may provide new insights for designing other high-performance heterojunctions as photocatalytic and photothermal catalytic nanomaterials.