Facile synthesis of metallic Bi deposited BiOI composites with the aid of EDTA-2Na for highly efficient Hg0 removal

BiOI microparticles with different I/Bi molar ratios were synthesized via a facile coprecipitation method in the absence and presence of EDTA-2Na and were characterized by various techniques. Their activity were evaluated using toxic elemental mercury as model pollutant under fluorescent lamp irradiation. The presence of EDTA-2Na would lead to the production of Bi, facilitating an effective separation of electron and hole pairs due to the transfer of electrons from BiOI surface to Bi. The lower the I/Bi molar ratio, the higher the Hg0 removal efficiency. The superoxide radicals and holes were the main reactive species for enhanced Hg0 removal.