Degradation of the azo dye Reactive Black 5 through peroxymonosulfate activation with functional S-doped graphene

Peroxymonosulfate (PMS) catalysis based on S-doped graphene (S-GN) is a useful technology for azo dye (Reactive Black 5, RBK5) wastewater treatment. Analyses upon characterization of materials indicated that special S functionalities were introduced into graphene, thereby improving the generation of new surface defects and active sites. In this research, the catalytic degradation of RBK5 by modified materials under different environmental conditions was analyzed. At pH 7 and PMS loading of 3 mmol/L, the degradation efficiency of 10 ppm RBK5 can reach almost 100%, and S-GN showed excellent ion-tolerance performance and cycle stability. The dominant radical species generated through the reaction were identified as SO4 center dot- and HO center dot by quenching experiment and electron paramagnetic resonance analysis. Density functional theory calculation was further proposed to determine the activation of PMS with S-GN.

Automated summary

Peroxymonosulfate (PMS) catalysis based on S-doped graphene (S-GN) is an effective technology for treating azo dye wastewater, improving the generation of new surface defects and active sites through the introduction of sulfur functionalities. Under appropriate conditions, S-GN exhibits high degradation efficiency, excellent ion-tolerance performance, and cycle stability towards RBK5.