Synergistic integration of metallic Bi and defective TiO2 for enhanced photocatalytic NO removal

The construction of hybrid catalysts is an effective method to enhance catalytic performance, but research on the positioning of the load is limited. In this study, we synthesized two photocatalytic materials by controlling the bismuth-titanium ratio and the site value of Bi modification in the catalyst. The surface-modified photocatalyst, namely 1:0.9 Bi/TiO 2 , exhibits a photocatalytic efficiency of 68.9 % for the abatement of ppb-level NO in the presence of visible irradiation. This efficiency was significantly superior to that of the corresponding one-step synthesized Bi/TiO 2 (48.7 %) and the TiO 2 (18.6 %). Furthermore, it promotes nitrate formation and suppresses the generation of toxic NO 2 . Capture experiments indicate that the same active species are involved in both surface-loaded and uniformly loaded catalysts. The differences in their performance can be attributed to the higher vacancy concentration in the surface-loaded catalysts and the different local coordination environments of vacancies in the catalysts, altering the adsorption capability of oxygen molecules. This work offers fresh perspectives for the generation of efficient photocatalysts.