Seaweed-derived multifunctional nitrogen/cobalt-codoped carbonaceous beads for relatively high-efficient peroxymonosulfate activation for organic pollutants degradation

Persulfate decontamination technologies utilizing transition metals as activators has been widely concerned for the treatment of organic contaminants; however, how to securely anchor active substances to heighten stability and introduce heteroatoms into carbon skeleton to improve catalytic activity are still facing great challenges. Herein, nitrogen/cobalt-codoped multifunctional carbonaceous beads (MCB, SA/N-CoxOy-X) have been successfully prepared by employing renewable sodium alginate and melamine via sol-gel assembly and carbonization methods. Compared to other related works, the acylation of nitrogen and the chelation reaction between carboxyl and cobalt can effectively stabilize nitrogen and cobalt, thus leading to a high dispersion and stabilization of heteroatoms. Characterization and catalysis experimental results identified that nanoparticles were embedded on SA/N network in-situ rather than surface. Different decoloration systems were carefully optimized, which illuminated that the surpassing efficiency was attributed to the synergy of nitrogen, carbon skeleton and cobalt species. More importantly, the broad-spectrum degradation capability of the catalyst was evaluated by efficiently degrading of several typical organic pollutants, such as ponceau, p-nitrophenol and tetracycline. Additionally, even after being used for ten times, catalyst still maintained high activity, which indicated its excellent stability. Besides, the coexisting anions and quenching experiments showed that both SO4 center dot- and OH center dot were the two main radicals and SO4 center dot- possessed widely scope application conditions, which was hardly affected by common anions. Finally, by virtue of the developed porous structure, unconventional electrons distribution and expanded texture, this type of semiconductor-like SA/N-CoxOy-X would be promising candidate for PMS activation and would possibly shed light on other fields.