Characterization and decontamination evaluation of carbon composites synthesized via Co(II)-Assisted pyrolysis of phenanthroline, phenylenediamine, and melamine

The application of carbon composite materials (CCMs) spans across various fields, and their preparation primarily involves the non-oxygen pyrolysis of non-volatile macromolecular precursors, which poses challenges in tailoring their composition and microstructure. Here, we propose a binary co-pyrolysis approach for the synthesis of CCMs, utilizing small organic molecules such as Phenanthroline (Phen), o -Phenylenediamine ( o PD), and Melamine (Mel) as precursors, along with Co(II) salt as a catalyst. We conducted a thermogravimetric analysis of these three binary systems, aiming to synthesize CCMs at moderate temperatures (330 − 460 °C). Subsequently, we characterized the CCMs in terms of their bulk structure, composition, and surface properties. Finally, we assessed their decontamination performance through catalytic H 2 O 2 degradation of methylene blue and adsorption of Pb(II)/phosphate. The results revealed that Co(II) can promote the preferential formation of thermally stable intermediate polymeric structures and inhibit the direct evaporation of the precursors. The prepared CCM-Phen-Co, CCM- o PD-Co, and CCM-Mel-Co exhibit a lamellar and (N, O, Co)–co-doped amorphous structure. Furthermore, both CCM-Phen-Co and CCM- o PD-Co demonstrate complete removal efficiency for methylene blue at a concentration of 10 mg/L, while the maximum adsorption capacity of CCM- o PD-Co for Pb(II) and CCM-Phen-Co for phosphate are 58.0 mg/g and 13.6 mg/g respectively. The CCMs demonstrate promising efficacy in environmental catalysis and adsorption for decontamination purposes.