Enhancement of photocatalytic activities of nitrogen-doped titanium dioxide by ambient plasma

Abstract

Nitrogen doped titanium dioxide (TiO2) was prepared by the hydrothermal method and modified by air plasma for photocatalysis. The bandgap of TiO2 reduced from 3.1 eV to 2.7 eV, and the photocurrent response was enhanced by 3.6 times compared to pure TiO2. The photocatalytic activity was tested by degrading methyl blue (MB) under the ultraviolet irradiation, showing that the rate constant increased from 0.009 to 0.031 min−1 after the plasma treatment. The enhanced photocatalytic activity was attributed to the nitrogen doping as well as the ambient plasma treatment, changing the electronic structure, active surface area, and crystallite size of TiO2.