Enhanced photocatalytic degradation of tetracycline using hydrothermally synthesized carbon fiber decorated BaTiO3

Abstract Barium titanate (BaTiO3) has been emerged as an efficient photocatalyst due to its optical and electromechanical properties. However, due to large band gap of BaTiO3, different materials are used to decrease band gap energy. In this study, carbon fiber (CF) was used to decrease band gap energy of BaTiO3 and the photocatalytic activity for the degradation of tetracycline was investigated under UV and visible light irradiation. BaTiO3/CF was synthesized by hydrothermal method for different CF ratios (5–15 wt %). BaTiO3/CF/5 catalyst showed the best degradation efficiency (96% under UV light) among the other samples. The photocatalysts were characterized by XRD, SEM-EDAX, FTIR analysis, etc. According to XRD analysis, high crystallinity was observed for both BaTiO3 and BaTiO3/CF. Besides, FTIR results also show the evidence of carbon fiber over the BaTiO3 structure. First-order reaction rate constant, kapp, was calculated using Langmuir-Hinshelwood equation. The kapp values were found as 1.63*10−2 min−1 under UV-A light and 1.46*10−2 min−1 visible light irradiation for BaTiO3/CF/5. According to stability tests, after the first cycle tetracycline degradation was found as 96%, while it was 77% after fifth cycle.