Preparation and characterization of visible-light-driven N-F-Ta tri-doped TiO2 photocatalysts

► N-F-Ta tri-doping can further improve the visible-light photoactivity of N single doped TiO2. ► There are N 2p-Ta 5d hybridized states which narrow the band gap and reduce the photogenerated electrons and holes recombination rate located in the gap region of TiO2. ► The introduced F atoms enhance the N incorporation which further promote the N 2p-Ta 5d hybridized states. ► Charge compensation during the doping process is a very important factor.