NIR-Responsive Photocatalytic Activity (980nm and 794nm) of NaYF4:YB, Tm-Tio2 and NaYF4 :Yb, Tm, Nd@NaYF4:Nd-TiO2 Colloidal Spheres

Abstract

This study fabricated two new kinds of photocatalyst (NaYF4: Yb, Tm-TiO2 and NaYF4:Yb/Tm/Nd@NaYF4:Nd-TiO2 colloidal spheres) successfully for NIR-responsive photocatalysis. The optimal synthesis conditions and doping concentration of rare earth ions for the new materials are established. TEM and XRD analysis confirm this 3D colloidal spheres structure. UV light energy emitted from upconversion materials has been utilized by this material to generate photo-generated electron-hole pairs, which then combine with the surface water or hydroxyl to generate sufficient amount of ?OH for photocatalytic degradation of organic pollutants. These new materials present very good photocatalytic activity and could enhance utilization efficiency for solar energy. NaYF4:Yb/Tm/Nd@NaYF4:Nd-TiO2 colloidal spheres can not only utilize 980 nm light but also 794 nm light when irradiated by solar light. More importantly, this new material can avoid energy consumption by water and consequent heating effect under 980 nm excitation.