Constructing Ti(III)-laden TiO2 nanotube arrays for electrochemical defluorination of levofloxacin. Issue 2 (April 2023)

• Record Type: Journal Article
• Authors: Pan, Meilan; Tang-hu, Shuang-yin; Ni, Chenhao; Chen, Haihua; Pan, Bingjun
• Is Part Of: Journal of environmental chemical engineering. Volume 11:Issue 2(2023)
• Publication Date: 2023-04
• Subjects: TiO2 nanotube arrays -- Trivalent titanium -- Levofloxacin -- Defluorination -- Sulfate radical; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2023.109392
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: Fluorine-containing fluoroquinolones are cumulative toxins and pose a grave threat to health of animals and human beings, and an effective and feasible strategy to the defluorination by breaking C-F bond to decrease toxicity is in an urgent requirement. Herein, Ti(III)-laden TiO2 nanotube arrays (RTNA) were deliberately fabricated for electrochemical degradation and defluorination of levofloxacin (LVF). Characterizations verified that Ti(III) and oxygen vacancies were generated on RTNA via electrochemical reduction of TiO2 nanotube arrays (TNA). The degradation kinetics of LVF on RTNA (0.85 h −1 ) was increased by about 15 times as compared with that on TNA (0.06 h −1 ); the corresponding degradation and defluorination efficiencies by RTNA were also dramatically increased. Moreover, the effect of electrolyte on the defluorination efficiency suggests the significant role of sulfate; that is, abundant sulfate radical (SO4 - ) was generated in the media of sodium sulfate during the electrochemical oxidation process, and it served as the dominant radical to break C-F bond for the defluorination of LVF, whereas it is not the case for hydroxyl radical (OH) in sodium carbonate. The pathways and mechanisms of degradation and defluorination in electrolyte of sodium sulfate or carbonate were proposed and further confirmed the difference in the electrolyte-dependent degradation mechanisms. Graphical Abstract: ga1 Highlights: RTNA was fabricated with abundant Ti(III) and oxygen vacancies for defluorinating LVF. Almost complete defluorination of LVF was achieved with RTNA as the anode. The degradation kinetics of RTNA was increased about 15 times relative to that of TNA. SO4 - radicals were responsible for breaking C-F bond to defluorinate LVF. The degradation and defluorination pathways in different electrolytes were proposed.