Fabrication of a Z-Scheme Heterojunction Polyhedral-Shaped BiOIO₃/MIL-53(Fe) Photocatalyst for Enhancing Gaseous Hg⁰ Removal

Abstract

A Z-scheme heterojunction polyhedral-shaped BiOIO 3 /MIL-53(Fe) photocatalyst is prepared by a solvothermal method. The samples are characterized by XRD, XPS, SEM, TEM, FT-IR, UV−vis, PL, and other material characterization analysis methods. The photocatalytic performance of photocatalysts is studied for removal of vapor-phase mercury (Hg 0 ) under visiblelight irradiation. The results suggest that the Hg 0 removal efficiency of the BiOIO 3 /MIL-53(Fe) composite is significantly improved compared with that of . When the molar ratio of BiOIO 3 and MIL-53(Fe) is 2:1, the BiOIO 3 /MIL-53(Fe) composite photocatalyst exhibits the best Hg 0 removal efficiency, reaching 74.19%. BiOIO 3 and MIL-53(Fe) form a Z-scheme heterojunction with a suitable energy band structure, which results in the effective separation of photoinduced electron−hole pairs and delays their recombination. Finally, the photocatalytic oxidation mechanism of Hg 0 by the BiOIO 3 /MIL-53(Fe) composite is proposed, which paves the way for the study of the built-in electric field and electron transport channels between binary photocatalyst materials.

Phosphomolybdic acid hydrate encapsulated in MIL-53 (Fe): a novel heterogeneous heteropoly acid catalyst for ultrasound-assisted regioselective nitration of phenols

“…In this sense it has greatly attracted researchers because of its exceptional tunability and functionality. [52][53][54][55][56][57] Moreover, researchers have also aimed at designing effective functionalized MOF catalysts with organic and organometallic moieties. 48,[57][58][59][60][61][62] These methods which were applied to modify various types of catalysts, 61 heteropoly acids and other transition metal-catalysts have been successfully encapsulated into the pores of MIL-53 (Fe).…”

Study of Sheetlike BiOI/Rodlike Bi5O7I Composite Photocatalyst by In Situ Crystallization of BiOI with pH-Dependence for Hg0 Removal

“…Generally, the scavenger tests of the Bi-11.0 sample were conducted to explore the reactive oxygen species (ROS) in the photocatalytic process for 30 min. The benzoquinone (BQ) and isopropanol (IPA) capture agents were used to selectively capture superoxide radicals (·O 2 – ) and hydroxyl radicals (·OH), respectively. , As shown in Figure a, when the capture agents were added to the catalytic reaction system, the mercury-removal efficiency of Bi-11.0 decreased significantly. This phenomenon indicated that the ·O 2 – and ·OH reactive species played a significant role in the photocatalytic reaction process for Hg 0 removal.…”

Synthesis and Photocatalysis of Metal Oxide Aerogels: A Review

“…36 Highly porous metal oxide aerogels are also beneficial for decomposing gas-phase pollutants and toxic chemicals in the air. 238 An Ag/TiO 2 composite aerogel was prepared for removing toluene in the flowing air. 239 The results showed that 95.7% of 300 ppm of toluene was decomposed under light irradiation.…”

“…Highly porous metal oxide aerogels are also beneficial for decomposing gas-phase pollutants and toxic chemicals in the air . An Ag/TiO 2 composite aerogel was prepared for removing toluene in the flowing air .…”