Photocatalytic activity and characterization of AgCl/Ag composite for Hg⁰removal under fluorescent light irradiation

Abstract

A AgCl/Ag composite was synthesized via a facile precipitation method and applied to the photocatalytic oxidation removal of elemental mercury (Hg0) in a wet bubbling reactor under fluorescent light irradiation. The fresh photocatalyst and the used materials were characterized by N2 physisorption, X‐ray diffraction, scanning electron microscopy and energy‐dispersive X‐ray spectroscopy, diffuse reflectance spectroscopy, X‐ray photoelectron spectroscopy, and electron spin resonance. The results showed that the AgCl/Ag photocatalyst and fluorescent light have a great synergistic effect on Hg0 removal. A higher solution temperature was not favorable for Hg0 removal. The presence of lower concentrations of SO2 or NO showed little effect on Hg0 removal, whereas the inhibition of SO2 or NO on Hg0 removal became more serious with the SO2 or NO concentration increasing. Some amounts of Ag0 were produced onto the AgCl/Ag surface during the process of Hg0 removal in the absence and presence of SO2 or NO. The trapping experiments confirmed that •O2− was the primary reactive species in the photocatalytic process.

Insights into Efficient Removal of Gaseous Hg0 using AgIO3-Modified BiOI/CoFe2O4 Composites through Photocatalytic Oxidation

“…According to a previous study, 57 FSL illumination contains a small amount of light at 405 nm (about 3.06 eV); therefore, both BiOI and CFO could be photoexcited to electrons and holes in their conduction and valence bands, while AgIO 3 could not be excited because of its wide band gap (3.38 eV). 23 Besides, as shown in Figure 8b, AgI was generated after the reaction, thus the presence of AgI would construct a crossbonding bridge to connect with two semiconductors.…”

Insight into the Mercury Removal Mechanism of Copper Salt-Modified Biomass Coke in an Oxyfuel Combustion Atmosphere

“…Mercury in coal combustion flue gas was present in different forms including oxidized mercury (Hg 2+ ), particulate mercury (Hg p ), and elemental mercury (Hg 0 ). − The oxidized form of mercury can be dissolved in liquids and can be removed with the help of wet denitrification or wet desulfurization units (WFGD), while the particulate form of mercury could be mostly removed by dust collectors. ,, Elemental mercury was thermodynamically stabilized. It is challenging to remove elemental mercury industrially, and it is usually removed by oxidation to higher valence states by various adsorbents or catalysts .…”

Enhanced photocatalytic degradation of tetracycline hydrochloride by Ag/AgI/WO3·H2O composites

“…25 Among them, Ag nanoparticles (NPs) can be used to enhance the visible light absorption due to the surface plasmon resonance (SPR). 21,26 Moreover, AgI and semiconductors with matching band potentials can be utilized to aid in the separation of electrons and holes and therefore enhance the photocatalytic activities. 27,28 Based on the findings of the above studies, it should be a good approach to improve the photocatalytic performance of WO…”

“…In addition, numerous Ag/AgI composite photocatalysts with excellent photocatalytic performances have been developed, such as Ag/AgI/V I ‐BiOI, 8 Ag/AgI/Bi 3 O 4 Cl, 9 Ag/AgI/BiOI, 23 Ag/AgI/K 2 Ti 4 O 9 , 24 and Ag/AgI/TiO 2 25 . Among them, Ag nanoparticles (NPs) can be used to enhance the visible light absorption due to the surface plasmon resonance (SPR) 21,26 . Moreover, AgI and semiconductors with matching band potentials can be utilized to aid in the separation of electrons and holes and therefore enhance the photocatalytic activities 27,28 .…”