Broadband NaYF4:Yb,Tm@NaYF4:Yb,Nd@TiO2 Nanoparticles Anchored on SiO2/Carbon Electrospun Fibers for Photocatalytic Degradation of Organic Pollutants

Semiconductor photocatalysis is a promising strategy for wastewater treatment. However, a limited photoresponse range, rapid recombination of photoinduced charge carriers, poor stability, and other problems have posed obstacles to practical applications. Herein, a facile strategy to fabricate a near-infrared-driven broadband photocatalyst was developed by anchoring the core–shell nanostructure of NaYF4:Yb,Tm@NaYF4:Yb,Nd@TiO2 (Tm@Nd@TiO2) onto the surface of porous silica/carbon (mSC) electrospun fibers. The Tm@Nd@TiO2 nanoparticles (NPs) exhibited strong near-infrared light absorption and energy transfer from the NaYF4:Yb,Tm@NaYF4:Yb,Nd core to the TiO2 shell, triggering the photocatalytic reaction. In addition, the interconnected mesoporous structure and carbon network of Tm@Nd@TiO2/mSC was found to be beneficial in improving the adsorption capacity toward organic pollutants, promoting the separation of photogenerated carriers, and further improving the overall photocatalytic performance. The photocatalytic activity of Tm@Nd@TiO2/mSC nanocomposite was evaluated by degrading methyl orange solution in the visible-near-infrared and simulated sunlight regions. The Tm@Nd@TiO2/mSC nanocomposite exhibited excellent adsorption performance. The photocatalytic activity of Tm@Nd@TiO2/mSC was found to be 3 times higher than that of bare Tm@Nd@TiO2 over 60 min.