Fabrication of BiOIO3 nanosheets with remarkable photocatalytic oxidation removal for gaseous elemental mercury

Series of BiOIO3 photocatalysts prepared at different pH values via a facile hydrothermal method were used to remove gaseous elemental mercury under UV and LED light irradiation. Results showed that the morphology and crystal structure of BiOIO3 products could be controlled by the pH value of precursor. The BiOIO3 products could be obtained only at strong acid condition. The BiOIO3 sample with nanosheets morphology prepared at 2.03 ⩽ pH ⩽ 3.05 exhibited superior photocatalytic activity and nearly 100% of Hg0 were removed after UV light (25 min) and LED light (100 min) irradiation. The removal efficiency of Hg0 was higher than that of P25 (UV light, 77%, LED light, 42%) under the same condition. The photogenerated holes were the main oxidative species responsible for the oxidation removal of Hg0. This newly BiOIO3 photocatalysts, with superior photocatalytic activity and good stability have potential application for the Hg0 oxidation removal.