Enhanced Mediated Electron Transfer Pathway of Peroxymonosulfate Activation Dominated with Graphitic-N for the Efficient Degradation of Various Organic Contaminants in Multiple Solutions

Abstract

Persulfate activated by carbon catalysts raised tremendous attention as a promising approach for degrading organic contaminants because the nonradical species produced can resist the interference of background substances. However, due to the complex and diverse structures of carbon catalysts, the reported peroxymonosulfate (PMS) activation mechanisms are varied. Herein, we used fabricated N-doped carbon nanotubes with a simple one-dimensional structure as a model catalyst to reveal the nature of PMS activation by carbon catalysts. The graphitic-N was identified as the active center to play a dominant role via structure–activity relationship analysis and density functional theory (DFT). Moreover, electron paramagnetic resonance, radical scavenging tests, and in situ Raman spectra demonstrated that the generated common reactive oxygen species did not contribute to carbamazepine (CBZ) degradation, but the electron transfer process directly oxidized the organic. Fortunately, the direct electron transfer pathway could quickly and simultaneously degrade various organics (including CBZ, sulfamethoxazole, bisphenol A, diclofenac, and tetracycline). In addition, the nature of degradation differences of various organics was revealed through the Fukui function calculated by DFT. This work revealed the mechanism of PMS activation by graphitic-N to produce mediated electron transfer pathways and provided an insight into the decomposition difference of various organic contaminants.

Porous Mn2O3/pSiO2 Nanocomposites on Bio-scaffolds for Tetracycline Degradation

“…1.2 V. Comparatively, Mn 2 O 3 / p SiO 2 presents a more intense oxidation peak at a larger potential (1.6 V), implying the strong interactions between Mn and Si in Mn 2 O 3 / p SiO 2 , which is consistent with the FTIR results (Figure S5). Furthermore, Mn 2 O 3 / p SiO 2 exhibits the lowest Tafel slope among the three samples, suggesting the faster reaction dynamics and better electron transfer capability of Mn 2 O 3 / p SiO 2 than n Mn 2 O 3 and p SiO 2 (Figure c) . EIS analysis was carried out to further clarify the mechanism of charge transfer between the catalyst surface and the reaction solution.…”

“…Furthermore, Mn 2 O 3 /pSiO 2 exhibits the lowest Tafel slope among the three samples, suggesting the faster reaction dynamics and better electron transfer capability of Mn 2 O 3 / pSiO 2 than nMn 2 O 3 and pSiO 2 (Figure 7c). 59 carried out to further clarify the mechanism of charge transfer between the catalyst surface and the reaction solution. Nyquist plots show that Mn 2 O 3 /pSiO 2 has the smallest semicircle diameter (Figure 7d), indicating its lowest resistance and highest conductivity among the three catalysts, which is expected to accelerate electron transfer.…”

Enhanced Peroxymonosulfate Activation by a Benzoquinone-Functionalized Carbon Nanotube Filter for Micropollutant Degradation

“…Advanced oxidation processes that leverage the functionality of peroxymonosulfate (PMS) are some of the most effective technologies for the mitigation of organic pollutants in water, which are generated from unsustainable industrial and agricultural expansion and rapid economic development. − The activation of PMS by transition metals has been extensively investigated because of its operational simplicity, minimal energy consumption, and high efficiency. ,,− However, a few key technical limitations hinder the widespread application of transition-metal-activated PMS systems, including their poor stability, the formation of a metal-rich sludge, and the potential for secondary pollution. − As an alternative, the use of metal-free organic compounds, such as polyaniline and quinones, for mediating the activation of PMS has recently gained attention. These organic compounds exhibit redox activity due to their high electron density and strong electron-donating characteristics.…”

Layer-by-Layer-Assembled Loose Nanofiltration Membrane for Persulfate Activity Enhancement: Performance and Process Regulation

“…13 The recyclability and recovery of the catalyst are as important as improving the catalytic efficiency toward heterogeneous AOPs. 14,15 To achieve the efficient and long-term operation of AOPs under a specific process, various attempts including magnetic catalysis and immobilization were made by researchers. 16 Consequently, optimizing the catalytic performance and operation by membrane separation appears to be a feasible strategy.…”

“…Moreover, PMS-based oxidation was readily accessible in a wider pH range compared with the Fenton system. , The high redox potentials of SO 4 •– ( E 0 = 2.5–3.1 V) and • OH ( E 0 = 1.8–2.7 V) endow PMS-based oxidation with high reactivity toward refractory substances . The recyclability and recovery of the catalyst are as important as improving the catalytic efficiency toward heterogeneous AOPs. , …”