Highly active β-NaYF4:Yb/Er-N-TiO2 nanoparticles for NIR light driven Rhodamine B degradation

Composite nanoparticles consisting upconversion nanoparticles (β-NaYF 4 :Yb/Er) and nitrogen doped TiO 2 nanoparticles were constructed via a chemical assembly method. Efficient energy transfer was enabled since the upconverted energy matched up with the band gap of N-TiO 2 . This enables the resulting composite nanoparticles to possess excellent Rhodamine B (RhB) degradation activity under near infrared (NIR) light irradiation. Composite β-NaYF 4 : Yb/Er-N-TiO 2 nanoparticles were synthesized via a chemical assembly method. They exhibited excellent Rhodamine B degradation activity under NIR light irradiation due to their high upconversion efficiency and high energy transfer efficiency. • β-NaYF 4 :Yb/Er exhibits high UC efficiency after optimizing the synthetic process. • Nitrogen doping narrows the band gap of TiO 2 . • β-NaYF 4 :Yb/Er is assembled with N-doped TiO 2 via an esterification reaction. • Energy transfer between β-NaYF 4 :Yb/Er and N-doped TiO 2 is permitted. • Composite β-NaYF 4 :Yb/Er and TiO 2 nanoparticles show high photocatalytic activity.