NH3 removal using the dielectric barrier discharge plasma-V-TiO2 photocatalytic hybrid system

Abstract

This study investigates the photocatalytic performance of V-TiO 2 for removal of highly concentrated ammonia (1,000 ppm) in the dielectric barrier discharge (DBD), plasma-photocatalytic, hybrid system. The V (1.0, 5.0, 10.0 mol-%)-TiO 2 photocatalysts were prepared by using the conventional sol-gel method. Their surface areas were decreased with increasing vanadium component. The UV-visible absorption band slightly shifted to more visible wavelengths in V-TiO 2 compared to that in pure TiO 2 . The NH 3 -TPD result confirmed that the ability of NH 3 adsorption on the surface of V-TiO 2 increased with increasing vanadium content, and was maximized for 5.0-mol% V-TiO 2 . The NH 3 decomposition was enhanced with the photocatalyst compared to the decomposition rate without catalysts, while the decomposition was further increased with the applied plasma voltage. The NH 3 decomposition reached 90% after 400 min at an applied plasma voltage of 10.0 kV, and various intermediates, such as -NH 2 , -NH, and NO, were also identified by using the Fourier transform infrared (FT-IR) spectra. In addition, the NH 3 decomposition reached 100% in the plasma-5.0 mol% V-TiO 2 , photocatalytic, hybrid system after 25 min, compared to 98% in the pure V-TiO 2 photocatalytic system after 150 min. In addition, the various undesirable byproducts were depressed when V-TiO 2 photocatalyst was used compared to that in the non-catalytic system.