Details

Autor(en) / Beteiligte

• Chen, Zesen
• Chen, Weirui
• Liao, Gaozu
• Li, Xukai
• Wang, Jing
• Tang, Yiming
• Li, Laisheng

Titel

Flexible construct of N vacancies and hydrophobic sites on g-C3N4 by F doping and their contribution to PFOA degradation in photocatalytic ozonation

Ist Teil von

• Journal of hazardous materials, 2022-04, Vol.428, p.128222-128222, Article 128222

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• N vacancies, hydrophobic sites and electron rich zone were simply regulated by doping F into g-C3N4 (CN) to accelerate photocatalytic ozonation of PFOA. Activity of F-CN was superior to that of CN, with 74.3% PFOA removal by F-CN/Vis/O3 but only 57.1% by CN/Vis/O3. Experimental results and theory simulations suggested that the photogenerated hole (hvb+) oxidation with the help of N vacancies was vital for PFOA degradation. N vacancies on both CN and F-CN would trap O atom of PFOA and seize electron from α –CF2 group, which made PFOA more easily to be oxidized. Doping of F narrowed band gap, lowered the valence band position and enhanced the oxidation potential of hvb+. The hydrophobic sites would accelerate the mass transfer of O3 and PFOA, enhance O3’s single electron reduction with ecb- to generate hydroxyl radicals (•OH) and reduce the recombination of hvb+-ecb-. Under the joint function of hvb+, N vacancies and •OH, PFOA degradation in F-CN/Vis/O3 proceeded through the gradually shortening of perfluoroalky chain and loss of CF2 unit. The acute and chronic toxicity of generated short-chain perfluorocarboxylic acid toward fish, green algae daphnid were predicted by ECOSAR. And the toxicity change of solutions was examined by luminescent bacteria. [Display omitted] •F-CN had the superior activity over CN during photocatalytic ozonation of PFOA.•Doping of F endowed F-CN with stronger O3 affinity and introduced more N vacancies.•Joint function of hvb+, •OH and N vacancies was responsible for PFOA degradation.