Details

Autor(en) / Beteiligte

• Asghar, Anam
• Hammad, Mohaned
• Kerpen, Klaus
• Niemann, Felix
• Al-Kamal, Ahmed K.
• Segets, Doris
• Wiggers, Hartmut
• Schmidt, Torsten C.

Titel

Ozonation of carbamazepine in the presence of sulfur-dopped graphene: Effect of process parameters and formation of main transformation products

Ist Teil von

• The Science of the total environment, 2023-03, Vol.864, p.161079-161079, Article 161079

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The stability of graphene structure in sulfur-doped graphene catalyst is demonstrated to be a key aspect during the ozonation process. Enhancing the stability of the sulfur-doped graphene structure is therefore important to improve its catalytic activity during the ozonation process. However, this has remained a challenge so far. Therefore, we adopted a low-energy microwave plasma technique to synthesize a high purity sulfur-doped graphene (S ⎯ Gr) catalyst for the ozonation process. The effect of S ⎯ Gr in the ozonation process was tested using carbamazepine (CBZ; 0.05 mM) as a probe compound. A complete CBZ removal was obtained at an ozone concentration of 0.08 mM while in comparison with single O3, ∼1.5 and 2.5 times decrease in the formation of the two important intermediate transformation products i.e., BQM (1-(2-benzaldehyde) – 4-hydroxy (1H, 3H)-quinazoline-2-one) and BQD (1-(2-benzaldehyde) - (1H, 3H)-quinazoline-2, 4-dione) was observed. Radical scavenging experiments confirmed the formation of HO. The XPS results showed that the activity of S ⎯ Gr towards the formation of HO was positively related to S-bearing carbon atoms at the edge of the graphene structure. Therefore, the addition of S ⎯ Gr is directly linked with the formation of HO, which further contributed to the improved elimination of intermediate transformation products. With a low sulfur loss of 1 %, the microwave plasma synthesized S ⎯ Gr catalyst remained stable during ozonation, implying its feasibility in practical application. [Display omitted] •Stable sulfur-doped graphene catalyst was prepared by microwave plasma technique.•S-bearing carbon atoms of graphene are active sites for O3 decomposition into HO.•Decreased formation of transformation products in O3+ S ⎯ Gr process.