Using Gd-Enhanced β-NaYF4:Yb,Er Fluorescent Nanorods Coupled to Reduced TiO2 for the NIR-Triggered Photocatalytic Inactivation of Escherichia coli

β-NaYF4:Yb,Er,Gd fluorescent nanorods were successfully coupled to a reduced TiO2 (UCNPs@R-TiO2) nanocomposite and applied visible-light catalytic sterilization under 980 nm near-infrared (NIR) light illumination. The UCNPs (β-NaYF4:Yb,Er,Gd) absorb the NIR emit red green light. visible can be absorbed by R-TiO2 (Eg = 2.8 eV) for photocatalytic reaction. About 98.1% of Escherichia coli effectively killed upon 12 min irradiation at minimum inhibitory concentration (MIC) 40 μg/mL UCNPs@R-TiO2 nanocomposite. bactericidal properties further evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. We found that high activity was due synergistic effect between R-TiO2. Moreover, show excellent upconversion luminance properties, introduction visible-light-absorbed nanoparticles (2.8 conducive efficient separation utilization photogenerated electron-hole pairs.