The broad band around 1683-1680 cm -1 is assigned to the C=O stretch of the amide group (Figure ). The optical properties of the prepared materials were characterized using DRS spectra (Figure ). 1,3,5-Triazine-2,4,6-triamine (melamine) and H3L2 were recorded to compare with COFs materials (Figure ). Melamine and COF-3 are white color materials; thus, they show absorbance peaks at 230 nm and 239 nm (Figure ). The shift in the absorbance peaks in COF-3 indicates the formation of a framework containing melamine (Figure ). Nitrogen-containing ligand and their COFs are yellow-orange color materials; thus, they show an absorbance peak at 360-370 nm (Figure ). There is also a shift in the absorbance of H3L2 after the formation of COF-3, indicating the condensation with melamine moiety (Figure ). The chemical bonds of COF-1 were further characterized using XPS (Figure ). The elemental XPS survey shows only elements of C, N, and O (Figure ). The XPS analysis of C 1s shows peaks at binding energies (BE) of 284 eV, 288 eV, and 290 eV corresponding to C-C, -C=O, and -C-O, respectively (Figure ). The analysis of N 1s shows peaks at BE of 398.7 eV, 400 eV, and 402 eV corresponding to N-C of the amide group, C=N of pyridine, and C=N triazine ring, respectively (Figure ). O 1s spectrum shows peaks at 531.5, 534, and 536 eV corresponding to C=O, C-O-H, and N=C-O, respectively (Figure ). The thermal stability of the prepared materials was characterized using TGA (Figure ). The material exhibits thermal stability up to 350 o C and 425 o C for COF-3, and COF-1/COF-2, respectively (Figure ). Nitrogen adsorption-desorption isotherms confirm the presence of porous materials (Figure ). In general, polyamide exhibits low surface areas for several reasons, including the non-planar configuration of the bond . Thus, the prepared COFs can be used as a substrate for the in-situ synthesis of palladium nanoparticles. The synthesis procedure for Pd involves adding and reducing Pd 2+ ions via an in-situ approach (Figure ).