One-pot synthesis of ultrafine NiO loaded and Ti3+ in-situ doped TiO2 induced by cyclodextrin for efficient visible-light photodegradation of hydrophobic pollutants

摘要

Inability to absorb visible light and fast recombination of photogenerated electrons and holes in TiO2 catalysts prevent their wide applications in photocatalysis. Herein, we report a novel strategy to in-situ synthesize Ti3+- doped TiO2 coupling with homo-dispersed NiO and beta-cyclodextrin (CD-Ni/TiO2). By using nickel stearate as precursor, ethyl acetoacetate and CD as chelating agents, porous CD-Ni/TiO2 nanospheres constructed by CD, ultrafine NiO (similar to 2 nm), and Ti3+-doped TiO2 (similar to 5 nm) are produced. The porous nanosphere structure enhances the surface utilization and electron-hole separation through intimate contact of NiO and TiO2. The doped Ti3+ extends the photo-response of TiO2 to visible region; while the CD structure with hydrophobic cavity endows CDNi/TiO2 with outstanding capability to entrap hydrophobic molecules. The CD-Ni/TiO2 with decreased band gap (2.70 eV) presents high activity and stability in visible-light photodegradation of hydrophobic pollutants. This study presents a simple strategy in TiO2 doping and activity enhancement through designing inorganic-organic composite photocatalyst for hydrophobic pollutant degradation under visible light.