Photodegradation of Ibuprofen, Cetirizine, and Naproxen by PAN-MWCNT/TiO2-NH2 nanofiber membrane under UV light irradiation

Abstract

Background: In this study, the photodegradation of three pharmaceuticals, namely Ibuprofen (IBP), Naproxen (NPX), and Cetirizine (CIZ) in aqueous media was investigated under UV irradiation. The photocatalyst used in this work consists of surface functionalized titanium dioxide (TiO₂-NH₂) nanoparticles grafted into Polyacrylonitrile (PAN)/multi-walled carbon nanotube composite nanofibers. Surface modification of the fabricated composite nanofibers was illustrated using XRD, FTIR, and SEM analyses.

Results: Sets of experiments were performed to study the effect of pharmaceuticals initial concentration (5-50 mg/L), solution pH (2-9), and irradiation time on the degradation efficiency. The results demonstrated that more than 99% degradation efficiency was obtained for IBP, CIZ, and NPX within 120, 40, and 25 min, respectively.

Conclusions: Comparatively, the photocatalytic degradation of pharmaceuticals using PAN-CNT/TiO₂-NH₂ composite nanofibers was much more efficient than with PAN/TiO₂-NH₂ composite nanofibers.

Keywords: Cetirizine; Composite nanofibers; Ibuprofen; Naproxen; Photocatalytic; UV-light.

Fig. 1

Effect of photocatalyst amount on the photodegradation efficiency of IBP, NPX, and CTZ under UV-light irradiation using PAN-MWCNT/TiO₂–NH₂ composites nanofibers. The drug solution = 5 mg/L, pH = 2, and total volume of 100 mL, irradiation time (IBP = 120 min, NPX = 40 min, CIZ = 25 min)

Fig. 2

Photodegradation efficiency of IBP, NPX, and CIZ as a function of UV-light exposure time. The drug concentration = 5 mg/L, total volume = 100 mL, and pH = 2

Fig. 3

Effect of the initial drugs concentration on the degradation efficiency under UV-light irradiation at pH 2, drug solution volume of 100 mL, and irradiation time of IBP = 120 min, NPX = 40 min, and CIZ = 25 min

Fig. 4

Effect of the pH on the degradation efficiency for IBP, NPX, and CIZ at initial concentration of 5 mg/L, drug solution volume of 100 mL, and irradiation time of IBP = 120 min, NPX = 40 min, and CIZ = 25 min

Fig. 5

Stability of the composite nanofibers for the photodegradation of IBP, CTZ, and NPX at initial concentration 5 mg/L, drug solution volume of 100 mL, irradiation time of IBP = 120 min, NPX = 40 min, and CIZ = 25 min

Fig. 6

SEM of a PAN nanofibers and b PAN-MWCNT/TiO₂–NH₂ composite nanofibers

Fig. 7

FTIR spectra of PAN, PAN-MWCNT, PAN/MWCNT-TiO₂, and PAN-MWCNT/TiO₂–NH₂ composite nanofibers

Fig. 8

XRD patterns of PAN-CNT/TiO₂–NH₂ composite nanofibers before and after the photocatalytic degradation