Résumé
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•Conducting polymers PANI and PPy have high potential to degrade organic contaminants in water.•New stable hydrogels beads PANI@Alg and PPy@Alg displayed excellent catalytic properties.•Conjugated systems of PANI and PPy can facilitate the electrons transfer during the PS activation.•SO4−O and 1O2 were generated and functioned in metal-free catalysts/PS system.
Engineering of new heterogeneous metal-free catalysts is of great importance for persulfate activation. Herein, Innovative conductive polymers Polyaniline (PANI) and Polypyrrole (PPy) were used as promising catalysts for PS activation to effectively degrade organic pollutants. In fact, PANI and PPy can provide the necessary electron transfer based on nitrogen atoms located in the conjugated chains compared to their counterparts in the defective sites. In addition, PANI and PPy were immobilized inside membrane formed by cross linking alginate biopolymer by divalent calcium ions, in order to develop a new stable hydrogel beads catalyst. The prepared hydrogels-activated PS process could maintain excellent catalytic properties, mitigate catalysts deactivation, increased chemical stability and offer hope for their application in the industrial scale. The radical scavenging experiments monitored by the electron paramagnetic resonance and functional theory calculations, indicated the role of the PANI and PPy conjugated chains and the nature of the reaction pathways.