Highly efficient removal of methyl iodide gas by recyclable Cu-based mesoporous silica.

Developing recyclable adsorbents for co-capture of I and CHI gas is a meaningful and challenging topic. Herein, Cu-based mesoporous silica (C-S) materials were synthesized and applied for CHI capture for the first time. Factors (Cu content, temperature, contact time and CHI concentration) affecting the adsorption behavior were investigated. The results demonstrated that the CHI adsorption capacity of the obtained C-S materials reached up to 1060 mg/g at 200 ℃. Furthermore, the C-S material exhibited excellent reusability (91.3 %, 5 cycles). It was found that Cu could cleave the carbon iodine bonds, causing CHI to dissociate into •CH and I. Then the Cu converted from Cu reacted with I to achieve the purpose of CHI capture. The adsorption mechanism of CHI on the C-S materials could be concluded that Cu reacted with CHI form CuI (Cu + CHI → CuI + •CH). This work suggested that the obtained C-S materials could be promising adsorbents for CHI capture.