Morphological Characterization of Ce-UIO-66 as a SERS Substrate: Insights from SEM and TEM

As an important component of the SERS substrate, Ce-UIO-66 was synthesized through traditional solvothermal method. In order to understand the morphology of Ce-UIO-66, it was characterized by SEM and TEM. From the SEM image in Figure 2a and the TEM image in Figure 2b, it can be observed that the material mostly consists of agglomerates of spherical particles with diameters ranging from 300 to 500 nm, which is consistent with previous literature [40]. Then, bimetallic gold core-silver shell nanoparticles (Au@Ag) prepared by the reduction method were added and magnetically stirred. It is evident that the surface of Ce-UIO-66 becomes rough due to the addition of silver-coated gold nanoparticles (Au@Ag), as shown in Figure 2c. Tiny Au@Ag particles can be clearly seen adhered to the surface of Ce-UIO-66, but its framework structure is still visible.