XRD is widely used to determine the crystal structure in carbonaceous materials, while Raman spectroscopy has also been established as a complementary technique for probing the microstructure of carbonaceous supports based on structural parameters calculated by XRD. Both of these two tests work synergistically to provide structural information on Co@CS catalysts. The XRD spectrum (Fig. ) shows that the peak at 20.16 o can be attributed to the typical characteristic peak of chitosan, while strong diffraction peaks appear at 2θ = 44.216, 51.522, and 75.853, which correspond to the crystal (111), (200), and (220) planes of Co, respectively, indicating that metallic cobalt has been successfully loaded on the chitosan support. Combined with Raman spectroscopy (Fig. ), the two characteristic Raman peaks at 1343 cm -1 and 1571 cm -1 can be attributed to the D band and G band, which are related to disordered carbon and sp 2 hybridized graphitic carbon structures, respectively. The intensity ratio (ID/IG) represents the degree of graphitization and disorder of the carbon material. The ID/IG value of Co@CS is higher than that of the carrier CS, indicating that there are more defect sites due to the introduction of Co substance.