Boosting Reactive Oxygen Species Generation by Regulating Excitonic Effects in Porphyrinic Covalent Organic Frameworks

Abstract

Excitonic effects play a crucial role in determining the photocatalytic performance of polymer semiconductors, which has long been ignored. Herein, metal organic frameworks (MOFs, specially NH₂-MIL-125) modifying porphyrinic covalent organic frameworks (COFs, specially DhaTph) have been proven to be a suitable model to regulate excitonic effects. The photoluminescence measurements prove that DhaTph presents strong excitonic effects, which can generate ¹O₂ through an energy transfer process. Remarkably, the construction of the NH₂-MIL-125@DhaTph heterostructure can effectively facilitate the dissociation of excitons, resulting in distinct activation of O₂ to O₂^•- and •OH. Benefiting from the enhanced generation of reactive oxygen species, the NH₂-MIL-125@DhaTph composite exhibits a superior bactericidal effect and photocatalytic degradation performance. This work provides a deeper insight into the excitonic effects based on COFs during the photocatalytic process and opens a feasible avenue for the regulation of the excitonic effects in porphyrinic COFs.