Preparation of magnetic mesoporous carbon based on polydopamine and their superperformance for adsorption of dye pollutants

Dopamine self-polymerized on the pore channel of SBA-15 as carbon precursor, and Fe3+. coordinated with polydopamine (PDA) as iron source to prepare a novel material. After calcination at 600 degrees C for 2 h, PDA was carbonized and Fe-3 was converted to magnetic nanoparticles. Then the SBA-15 template was dissolved with 3 mol/L ethanol-NaOH solution, magnetic mesoporous carbon (MMC) material was obtained. The resulted MMC was characterized by various instruments, and the results proved that tiny magnetic nanoparticles were distributed uniformly on the carbon matrix, and mesoporous structure of the carbon substrate was confirmed. Three organic dyes were selected as target pollutants to investigate the adsorption behavior of MMC. Under the optimal condition, the maximum adsorption capacity calculated from Langmuir adsorption isotherm for congo red, neutral red and methyl green were 2,315.4; 2,431.6 and 2,927.1 mg.g(-1), respectively. Furthermore, the maximum adsorption capacity in natural water showed no obvious decrease, indicating strong anti-interference ability of the sorbents. Gibbs free energy calculated from thermodynamics data was negative, demonstrating that the adsorption was a spontaneous process. Due to the excellent adsorption performance of carbon material, high specific surface area, and a large number of adsorption sites on the mesoporous structure, the MMC showed ultrahigh adsorption capacity for organic dyes, indicating its great potential for dye pollutants removal.