Photocatalytic activity of β-MnO2 nanotubes grown on PET fibre under visible light irradiation

Abstract

Development of visible light response semiconductor photocatalysts in degradation of organic compounds (pollutants) is one of the current research focuses due to the severe environmental pollution from various industrial and agricultural pollutants in water bodies. In this work, β-MnO2 particles were successfully prepared by sol-gel method with potassium permanganate and manganese (II) sulphate as precursors. The transmission electron microscope/selected area electron diffraction analysis indicates that the particles were polycrystals with tubular structure. The photodegradation of Rhodamine B (RhB) solution using β-MnO2 nanotubes under visible irradiation followed 1st order kinetic with rate constant of 0.022 ± 0.003 min−1 and photodegradation efficiency of 90.3% after 120 min under visible light irradiation. The N-deethylation was the dominant process in photodegradation of RhB dye by β-MnO2 nanotubes as compared to cycloreversion process. By applying similar synthesis condition, the β-MnO2 nanotubes were successfully synthesised on PET fibre. The photodegradation efficiency of RhB dye under circulation condition by β-MnO2 nanotubes grown on PET fibre under visible light irradiation was 1.23 h−1. The result suggests that β-MnO2 nanotubes grown on PET fibre could be used as visible light-driven photocatalysts for wastewater purifier application.