Enhanced generation of oxidative species and phenol degradation in a discharge plasma system coupled with TiO2 photocatalysis

In this paper, the streamer formed during a pulsed discharge process was used as it lamp house to induce the photocatalysis of TiO2 in a pulsed discharge plasma system. A synergistic effect of plasma and TiO2 photocatalysis was revealed through a comparison of the generated amounts of oxidative species ((OH)-O-center dot, O-center dot, H2O2) and phenol decomposition in the plasma system with and without Supported TiO2. A spectral analysis of oxidative radicals such as (OH)-O-center dot and O-center dot identified a higher emission intensity of the radicals in the plasma/TiO2 system than in the plasma alone system. Both the H2O2 concentration and the phenol degradation in the plasma/TiO2 system were higher than those in the plasma alone system. Furthermore, higher energy efficiency of phenol decomposition and total organic carbon (TOC) removal was achieved in the plasma system coupled with TiO2 photocatalysis. Moreover, the streamer was proved to be in existence by measuring the power in the systems of plasma alone and plasma-photocatalysis system. This coupling process can be further Studied to identify and exploit the existence of streamers in plasma channels. (C) 2008 Elsevier B.V. All rights reserved.