Application of TiO2 nanotubes with pulsed plasma for phenol degradation

This report describes a method for phenol degradation by photocatalysis using a streamer discharge above the liquid surface combined with a film of TiO2 nanotubes. The removal efficiency was about 98% after a 60 min reaction when a 20 kV discharge was combined with the film of TiO2 nanotubes. The removal efficiency was only 60% with discharge alone. The phenol degradation was fitted to a pseudo-first-order kinetic model. The energy utilization efficiency of the phenol oxidation was higher for the plasma/TiO2 photocatalysis system due to the synergy effect between the plasma discharge and the photocatalysis. The film of TiO2 nanotubes was calcined at 673 K. The degradation rate was significantly enhanced by the presence of TiO2. The crystal structure and surface morphology of the TiO2 showed no change after use and the photocatalytic activity of TiO2 was not affected. Higher concentrations of hydrogen peroxide and some intermediates from phenol oxidation were obtained using the combined plasma/TiO2 photocatalysis system.

• TiO2 nanotubes film was applied with streamer discharge along water surface. • TiO2 nanotubes film has high photocatalytic activity and long usage life. • The formation of activity species such as H2O2 was enhanced by plasma/TiO2 system. • The byproducts of phenol were analyzed to analyze the synergistic effect of plasma/TiO2 system. • High energy utilization efficiency was obtained during the plasma/TiO2 system.