Electrical properties of TiO$_{2}$ in a dielectric barrier discharge

The efficiency of plasma and photocatalyst (TiO$_{2})$ combination for volatile organic compounds removal is now proved in atmospheric pressure DBD in air [1]. This efficiency may be due to chemical activity of TiO$_{2}$ as well as geometry of the surface or electrical properties of this material. A complete study of electrical properties is performed to check how TiO$_{2}$ changes discharge current in a DBD. The average injected energy is compared in plasma, plasma + UV lamp, plasma + TiO$_{2}$, plasma + TiO$_{2}$ + UV. Then, a statistical study of current peak amplitudes is carried out at different times during one period of the sinusoidal power supply (50Hz). Several populations of current peaks are observed during the positive half period and the negative one. These populations change with and without TiO$_{2}$ even for the same averaged injected energy and may be a reason for the depolluting efficiency of plasma/TiO$_{2}$ combination. [1] Kang et al, \textit{Journal of Molecular Catalysis} (\textbf{2002})