New insights into N, S doped carbon from conjugated polymers for efficient persulfate activation: Role of hydrogel beads in enhancement of stability

• A new N, S co-doped carbon (NS-C) was prepared from polypyrrole-co-polythiophene conjugated copolymer. • N and S doping can effectively create a synergistic effect for persulfate activation. • A nonradical pathway ( 1 O 2 ) plays the dominate role in PS activation. • NS-C@Alginate hydrogel beads have prepared to improve the chemical stability and carbocatalyst separation. One-pot design of heteroatoms doped carbocatalysts for remediation of wastewater via persulfate (PS) activation is strongly desirable. Herein, a novel nitrogen and sulfur doped and co-doped carbons with controllable N, S doping is rationally prepared using pyrolysis strategy from polypyrrole-polythiophene polymers and copolymer. The N, S co-doped carbon (NS-C) show highly catalytic oxidation compared by N doped carbon (N-C) and S doped carbon (S-C) due to the synergistic effect between N and S dopants. It’s supposed that N and S doping can effectively create highly and main active sites to the electron transfer via PS activation, which could generate reactive oxygen species (ROS). Structure-dependent activity during activation of PS was confirmed by quenching experiments and electron paramagnetic resonance (EPR) analysis, prove that the non-radical species ( 1 O 2 ) is the main ROS generated. To improve the carbocatalyst separation and stability, the hydrogel beads-based alginate NS-C@Alginate were easily prepared. The catalytic efficiency rate by using the real water matrix shows that the NS-C/PS synergic system non-radical-led pathway exhibited a high ability to remediation of surrounding inorganic or organic compounds. This approach provides an innovative method for production and proves an efficient and environmentally benign carbocatalyst to PS activation for practical applications.