Title : Photocatalysis for degradation of environmental pollutants under VUV irradiation
Abstract:
Photocatalytic oxidation (PCO) is one of the fastest developed technologies for the control of environmental pollutants (in both gaseous and aqueous state) as well as for energy production (such as hydrogen generation and dye-sensitized solar cell). The PCO process is normally triggered by the irradiation of UV light. The most widely used UV sources in PCO are 254 nm and 365 nm UV lamp. However, conventional PCO process has disadvantages such as recombination of electron-hole pair leading to low efficiency and photocatalyst deactivation. In order to improve the efficiency and stability of the PCO process, UV lamps with partial 185 nm UV irradiation (denoted as VUV lamp) can be used to activate photocatalysts. 185 nm VUV lamps cannot only irradiate photocatalyst but also generate active oxidants such as O radicle, OH radicle, and ozone all of which enhance the oxidation of the organic components in the nearby pollutants. The VUV lamps are also facile, cheap, and energy efficient. In this paper, the results of VUV enhanced photocatalytic degradation of common VOCs (such as toluene and benzene) and water pollutants (such as methyl blue are acrylic wastewater) are presented and discussed. In addition, ozone is a byproduct generated in the process, which can enhance the oxidation but can also cause harmful effects on our health. The removal of the residue ozone using modified catalyst will also be discussed.
