Fabrication of BiOIO3/g-C3N4/Er3+ containing oxygen vacancies for photocatalytic oxidation of gaseous elemental mercury

Construction of heterojunction and formation of oxygen vacancy are effective methods to improve the performance of photocatalysts. In this work, Er 3+ -doped BiOIO 3 /g-C 3 N 4 photocatalyst with oxygen-rich vacancies was prepared by a simple hydrothermal and calcination method for the photocatalytic oxidation of elemental mercury. The structural properties of BiOIO 3 /g-C 3 N 4 /Er 3+ were analyzed by XRD, SEM and BET. The results showed that all samples exhibited good photocatalytic oxidation ability for Hg 0 under visible light irradiation. Among them, the photocatalyst with Er 3+ -doped BiOIO 3 /g-C 3 N 4 and then calcined has the highest removal efficiency of Hg 0 , which is 68.83%. This may be due to the increase of oxygen vacancy caused by Er 3+ doping, which enables the photocatalyst to have higher electron transfer rate and wider visible light absorption range. Finally, the possible mechanism of photocatalytic oxidation of gaseous elemental mercury with BiOIO 3 /g-C 3 N 4 /Er 3+ photocatalyst was proposed. This study provides some reference for the design and application of photocatalysts containing oxygen vacancies.