Immobilization of self-stabilized plasmonic Ag-AgI on mesoporous Al2O3 for efficient purification of industrial waste gas with indoor LED illumination

Abstract The immobilization of a photocatalyst on a proper support is pivotal for practical environmental applications. In this work, the plasmonic Ag-AgI with photoinduced self-stability was successfully immobilized on mesoporous Al 2 O 3 by a wet impregnation-precipitation and in-situ photoreduction method. The immobilized Ag-AgI/Al 2 O 3 was applied for photocatalytic removal of ppm-leveled NO under illumination of indoor LED tubes, which could obtain 100% NO removal in minutes at optimized conditions. The large dispersion of Ag-AgI on mesoporous Al 2 O 3 was firmly enough to overwhelm the continuous air flowing, and the enlarged surface area of Ag-AgI could efficiently enhance NO removal efficiency than pure Ag-AgI powder. Most importantly, the plasmonic Ag-AgI/Al 2 O 3 was stable in activity and can be used repeatedly without deactivation. On the basis of reactive species trapping and reaction intermediate monitoring, the responsible reactive species of photogenerated OH, O 2 − , H 2 O 2 and h + were confirmed and the possible reaction mechanism of photocatalytic NO oxidation by Ag-AgI/Al 2 O 3 was revealed. The present work could provide new perspectives for promoting large-scale environmental applications of supported plasma photocatalysts.