Enhanced visible-light driven degradation of carbamazepine and hydrogen evolution using nitrogen-doped TiO2 nanoparticles

초록

In this study, nitrogen-doped TiO2 (N-TiO2) nanoparticles (NPs) were prepared and investigated for removal of carbamazepine (CBZ) and hydrogen production. Optical, electronic, morphological, and structural characteristics of N-TiO2 were investigated through UV-DRS, PL, FTIR, XPS, SEM-EDX, and BET. N doping improved the characteristics of TiO2 as indicated by BET surface area of 115.5 m2 g- 1 for N-TiO2 compared to 72.6 m2 g- 1 for pristine TiO2. Besides, N doping reduced the bandgap of TiO2 from 3.2 eV to 2.8 eV (for N-TiO2). Moreover, NTiO2 demonstrated excellent photocatalytic activity for the removal of CBZ, achieving degradation efficiency of 88.1 and 99.1 % under visible and UV irradiation, respectively. The degradation process was conducted under the reaction conditions of: [CBZ]0 = 10 mg/L, [N-TiO2]0 = 0.7 g/L, pH = 5.0, reaction time = 300 min and temperature = 25 degrees C. Thermodynamic study reveals that the degradation process is endothermic and spontaneous, highlighting the feasibility of the reaction. Degradation products were analyzed to establish degradation pathways, and estimated their ecotoxicity using the ECOSAR program. Moreover, N-TiO2 effectively produced hydrogen under visible light, achieving hydrogen evolution rate of 354 mu mol h- 1 g- 1 using Pt (0.2 wt %) as a cocatalyst. These results indicate that nitrogen doping can modify the electronic structure and surface properties of TiO2, improving the separation of charge carries and increasing the active sites, making N-TiO2 as an effective photocatalyst for environmental remediation and green energy production.

키워드