Kinetics of oxygen species in an electrically driven singlet oxygen generator

The kinetics of oxygen species in the gaseous medium of a discharge singlet oxygen generator has been revisited. Vibrationally excited ozone O-3(upsilon) formed in O + O-2 recombination is thought to be a significant agent in the deactivation of singlet oxygen O-2(a(1 Lambda)), oxygen atom removal and ozone formation. It is shown that the process O-3(upsilon >= 2) + O-2(a(1)Delta) -> 2O(2) + O is the main O-2(a(1)Delta) deactivation channel in the post-discharge zone. If no measures are taken to decrease the oxygen atom concentration, the contribution of this process to the overall O-2(a(1 Delta)) removal is significant, even in the discharge zone. A simplified model for the kinetics of vibrationally excited ozone is proposed. Calculations based on this model yield results that are in good agreement with the experimental data. (C) 2015 Elsevier B.V. All rights reserved.