Near-Infrared-Driven β-NaYF4:Yb,Tm,Gd/Ni-MOF Nanocomposites for Efficient Sterilization and Degradation of Organic Contaminants

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) were utilized to analyze the structure, optical properties, composition, and morphology of the UNM nanocomposites. The photocatalytic performance of UNM was evaluated by testing its ability to kill E. coli and S. aureus as well as degrade rhodamine B (RhB) under 980 nm near-infrared light irradiation (1.0 W/cm(2)). After 18 min of reaction, the bactericidal rates against E. coli and S. aureus were observed to be roughly 100 and 99.99%, respectively. Similarly, similar to 98.49% of RhB was degraded within 180 min. Free radical capture experiments were conducted to further investigate the mechanism of UNM photocatalysis. The main active species involved were determined to be <middle dot>O-2(-) and h(+). In addition, UNM was able to retain similar to 86.25% of its degradation rate toward RhB after four cycles of cycling experiments, which demonstrated its good stability. Therefore, this study provides a potential strategy to eliminate bacteria and degrade hazardous pollutants in order to mitigate environmental pollution.