Effect of activator/precursor mass ratio on sulfur-doped porous carbon for catalytic oxidation of aqueous organics with persulfate. (September 2022)

• Record Type: Journal Article
• Authors: Guo, Yaoping; Xuan, Keng; Pu, Chenxi; Li, Yifan; Huang, Yaxiong; Guo, Yadan; Jia, Meiyu; Li, Jiale; Ruan, Hao
• Is Part Of: Chemosphere. Volume 303:Part 3(2022)
• Publication Date: 2022-09
• Subjects: Sulfur-doped -- Activated carbon -- Activator/precursor mass ratio -- Persulfate -- Aqueous organic; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.135192
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Sulfur-doped porous carbon has emerged as promising metal-free catalysts toward persulfate (PS) for catalytic oxidation of aqueous organics. Wherein, thermal pyrolysis with activator activation is very common for the preparation of activated carbon. However, the relationship between the mass ratio of activator/precursor and catalytic efficiency has been rarely reported. Herein, a series of sulfur-doped porous carbons (S-AC) were synthesized by one-step chemical activation of (Poly(phenylene sulphide) (PPS)) with K2 CO3 as activator at K2 CO3 /PPS mass ratio ranging from 0 to 3. The effects of K2 CO3 /PPS mass ratio on its physicochemical properties and its catalytic performance for p-chlorophenol (PCP) degradation with PS were comprehensively investigated. Experiment results show that sulfur doping enhanced its catalytic activity and the sample synthesized with K2 CO3 /PPS mass ratio of 2 (S-AC-2) exhibited the best adsorption and catalytic performance toward PS for PCP removal. More importantly, S-AC-2 with PS could efficiently degrade various aqueous toxic organics other than PCP, and S-AC-2 showed superior catalytic activity to many recently reported advanced materials. In addition, the effects of several operate parameters, including reaction temperature, PS concentration, pH, humic acid, and inorganic ions on PCP oxidation were evaluated. By combining with the results of quenching experiments and EPR, the PS activation mechanism over S-AC-2 was revealed. Moreover, the reusability and regenerability of S-AC-2 was also studied. It indicates that S-AC-2 showed inferior reusability, but the catalytic activity of which could be fully recovered through thermal treatment at 600 °C for 2 h in N2 . Graphical abstract: Image 1 Highlights: S-doped activated carbons (S-AC) were prepared by carbonizing PPS with K2 CO3 . The effect of K2 CO3 amount on the physicochemical properties of S-AC was discussed. S-AC-2 exhibited high catalytic activity toward persulfate for organics removal. Both radical and non-radical pathways participated in the PS activation process. The reusability, reasons for passivation, and regenerability of S-AC was studied.