Quantitative evaluation of structure-activity relationships in heterogeneous photocatalytic oxidation towards organic contaminants

Photocatalysis based advanced oxidation processes (AOPs) have drawn increasing attention for the removal of organic contaminants, while the relationships of the target organic contaminants with the intrinsic properties of the photocatalysts are usually neglected. Herein, the photocatalytic behaviors among ten kinds of organic contaminants and two heterojunction photocatalysts were comparatively investigated. Photocatalysts BiOCl0.75I0.25/g-C3N4 (BCI-CN) with abundant oxygen vacancies exhibited stronger absorption capacity towards light and quicker transfer efficiency of photoinduced carriers (factor η1×2) than BiOCl/g-C3N4 (BC-CN). Nevertheless, the redox ability (factor η3) of BCI-CN was weaker than that of BC-CN. Factor η1×2 and η3 synergistically and competitively affect the photocatalytic activities. Based on the differences and connections about intrinsic properties of BC(I)-CN photocatalysts, quantitative evaluation of structure-activity relationships among different organic contaminants and two photocatalysts were constructed, which provide valuable guidance for objectively evaluating the photocatalytic performance and precisely recognizing the compatibility among pollutants and photocatalysts.