TY - JOUR

T1 - UV/Vis Light Induced Degradation of Oxytetracycline Hydrochloride Mediated by Co-TiO2 Nanoparticles

AU - Akel, Soukaina

AU - Boughaled, Redouan

AU - Dillert, Ralf

AU - Azzouzi, Mohamed El

AU - Bahnemann, Detlef W.

N1 - Funding information: The authors wish to thank Luis Granone for XRD and Raman measurements, Barbara Nunes for TEM measurements, and Narmina Balayeva for the valuable discussions. The publication of this article was funded by the Open Access Fund of the Gottfried Wilhelm Leibniz Universität Hannover.

PY - 2020/1/7

Y1 - 2020/1/7

N2 - Pharmaceuticals, especially antibiotics, constitute an important group of aquatic contaminants given their environmental impact. Specifically, tetracycline antibiotics (TCs) are produced in great amounts for the treatment of bacterial infections in both human and veterinary medicine. Several studies have shown that, among all antibiotics, oxytetracycline hydrochloride (OTC HCl) is one of the most frequently detected TCs in soil and surface water. The results of the photocatalytic degradation of OTC HCL in aqueous suspensions (30 mg·L −1) of 0.5 wt.% cobalt-doped TiO 2 catalysts are reported in this study. The heterogeneous Co-TiO 2 photocatalysts were synthesized by two different solvothermal methods. Evonik Degussa Aevoxide P25 and self-prepared TiO 2 modified by the same methods were used for comparison. The synthesized photocatalysts were characterized by X-ray powder diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), UV/vis diffuse reflectance spectroscopy (DRS), and N2 adsorption (BET) for specific surface area determination. The XRD and Raman results suggest that Ti 4+ was substituted by Co 2+ in the TiO 2 crystal structure. Uv/visible spectroscopy of Co-TiO 2-R showed a substantial redshift in comparison with bare TiO 2-R. The photocatalytic performance of the prepared photocatalysts in OTC HCL degradation was investigated employing Uv/vis spectroscopy and high-performance liquid chromatography (HPLC). The observed initial reaction rate over Co-TiO 2-R was higher compared with that of Co-TiO 2-HT, self-prepared TiO 2, and the commercial P25. The enhanced photocatalytic activity was attributed to the high surface area (153 m 2·g −1) along with the impurity levels within the band gap (2.93 eV), promoting the charge separation and improving the charge transfer ability. From these experimental results, it can be concluded that Co-doping under reflux demonstrates better photocatalytic performances than with the hydrothermal treatment.

AB - Pharmaceuticals, especially antibiotics, constitute an important group of aquatic contaminants given their environmental impact. Specifically, tetracycline antibiotics (TCs) are produced in great amounts for the treatment of bacterial infections in both human and veterinary medicine. Several studies have shown that, among all antibiotics, oxytetracycline hydrochloride (OTC HCl) is one of the most frequently detected TCs in soil and surface water. The results of the photocatalytic degradation of OTC HCL in aqueous suspensions (30 mg·L −1) of 0.5 wt.% cobalt-doped TiO 2 catalysts are reported in this study. The heterogeneous Co-TiO 2 photocatalysts were synthesized by two different solvothermal methods. Evonik Degussa Aevoxide P25 and self-prepared TiO 2 modified by the same methods were used for comparison. The synthesized photocatalysts were characterized by X-ray powder diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), UV/vis diffuse reflectance spectroscopy (DRS), and N2 adsorption (BET) for specific surface area determination. The XRD and Raman results suggest that Ti 4+ was substituted by Co 2+ in the TiO 2 crystal structure. Uv/visible spectroscopy of Co-TiO 2-R showed a substantial redshift in comparison with bare TiO 2-R. The photocatalytic performance of the prepared photocatalysts in OTC HCL degradation was investigated employing Uv/vis spectroscopy and high-performance liquid chromatography (HPLC). The observed initial reaction rate over Co-TiO 2-R was higher compared with that of Co-TiO 2-HT, self-prepared TiO 2, and the commercial P25. The enhanced photocatalytic activity was attributed to the high surface area (153 m 2·g −1) along with the impurity levels within the band gap (2.93 eV), promoting the charge separation and improving the charge transfer ability. From these experimental results, it can be concluded that Co-doping under reflux demonstrates better photocatalytic performances than with the hydrothermal treatment.

KW - Co-TiO catalyst

KW - Oxytetracycline hydrochloride

KW - Photocatalysis

KW - Solvothermal synthesis

KW - Water treatment

KW - Microscopy, Electron, Transmission

KW - Anti-Bacterial Agents/chemistry

KW - Oxidation-Reduction

KW - Cobalt/chemistry

KW - Oxytetracycline/chemistry

KW - Titanium/chemistry

KW - Water Purification/instrumentation

KW - Ultraviolet Rays

KW - X-Ray Diffraction

KW - Light

KW - Nanoparticles/chemistry

KW - Spectrum Analysis, Raman

KW - Catalysis

KW - Water Pollutants, Chemical/chemistry

UR - http://www.scopus.com/inward/record.url?scp=85077912080&partnerID=8YFLogxK

U2 - 10.3390/molecules25020249

DO - 10.3390/molecules25020249

M3 - Article

C2 - 31936177

VL - 25

JO - MOLECULES

JF - MOLECULES

SN - 1420-3049

IS - 2

M1 - 249

ER -