The beta-NaYF4:Yb,Tm,Gd/Ni-MOF (UCNR/Ni-MOF, UNM) nanocomposites were successfully synthesized via a simple two-step hydrothermal method. Excited by a 980 nm laser, UCNRs produce ultraviolet and visible light, activating the Ni-MOF and generating a significant quantity of electron/hole pairs (e(-)/h(+)). These e(-)/h(+) pairs can then react with O-2 and H2O to create reactive oxygen species (ROS), which can be used for antibacterial purposes. Characterization techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR)...