Plasmonic Au Decorated Single-crystal-like TiO2-NaYF4 Mesoporous Microspheres for Enhanced Broadband Photocatalysis

摘要

Single-crystal-like TiO2 mesoporous microspheres have been reported with high photocatalytic activity under ultraviolet light (UV light) because of their high specific surface areas and single-crystal-like channel walls.In this work,plasmonic gold nanoparticles (Au NPs) and β-NaYF4:Yb3+,Er3+ upconversion nanoparticles (UCNPs) were composited with single-crystal-like TiO2 mesoporous microspheres through a series of facile approaches,aiming at broadening response region of solar light from UV to visible and near infrared light and enhancing the photocatalytic activity further.The structure was rationally designed by modifying the pore size of TiO2 mesoporous microspheres so as to anchor plasmonic Au NPs,and covering β-NaYF4∶ Yb3+,Er3+ with SiO2 in order to embed UCNPs into TiO2 mesoporous microspheres via hydrophilic interaction.This work studied the attribution of Au NPs and UCNPs to photocatalysis and found out that combining Au NPs and certain amount of UCNPs with single-crystallike TiO2 mesoporous microspheres in a monolithic architecture would bring enhanced broadband photocatalytic activity under simulated solar light.Consequently,the composite photocatalyts containing 150 mg UCNPs showed a significant enhancement in reaction rate,which was 36.02％ higher than commercial P25 and 85.09％ higher than pure TiO2 mesoporous microspheres under simulated solar light.