A series of Ag@AgCl-BiOCl photocatalysts were synthesized by a coprecipitation-photoreduction method and characterized by N2 adsorption-desorption

scanning electron microscope (SEM)

X-ray diffraction (XRD)

UV-visible diffuse reflectance spectroscopy (DRS)

X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) techniques to understand their physical-chemical structures. The effects of AgCl content

pH value

reaction temperature

SO2 and NO on the activities of elemental mercury (Hg0) removal were carried out in a wet Hg0 bubbling reactor under fluorescent light (FSL) irradiation. The results showed that a much higher Hg0 removal efficiency was obtained when the molar ratio of Ag to Bi was equal to 0.2 in the Ag@AgCl-BiOCl sample. With increasing pH value and reaction temperature

the Hg0 removal efficiency over Ag@AgCl(0.2)-BiOCl under FSL irradiation became gradually worse. Compared with SO2

NO showed a significant inhibitation on Hg0 removal. The mechanism analysis indicated that superoxide radicals (·O2-)

holes (h+)

hydroxyl radicals (·OH) and chlorine radicals (·Cl) could be reactive species in the photocatalytic process of Hg0 removal

and in particular the ·O2- played key role in Hg0 removal.