Functionalized Modification of Conjugated Porous Polymers for Full Reaction Photosynthesis of H₂O₂

Abstract

Modulating the molecular structure to achieve the full reaction including oxygen reduction reaction and water oxidation reaction is a promising strategy for efficient photosynthesis of hydrogen peroxide (H2O2) but remains a challenge. Herein, a triphenylamine and naphthalimide‐based conjugated porous polymers are synthesized with photo oxidation‐reduction structures, then sulfonate (─SO3H) and quaternary ammonium groups are introduced via a post‐modification strategy to produce two photocatalysts named NI‐TPA‐NI‐SO3H and NI‐TPA‐NI‐N, respectively. Introducing charged functional groups has improved the hydrophilicity and oxygen (O2) adsorption, beyond that, the ─SO3H further stabilizes the adsorbed O2 via hydrogen bonding as well as accelerates the photogenerated carrier separation and electron/proton transport that enables full reaction photosynthesis of H2O2. Therefore, motivated by efficient charge separation, stabilized O2 adsorption, and boosted proton‐coupled electron transfer, NI‐TPA‐NI‐SO3H exhibits the highest light‐driven H2O2 production rate among the three photocatalysts, reaching 3.40 mmol g−1 h−1, which is 4.9‐fold of NI‐TPA‐NI. Remarkably, in the presence of ethylenediaminetetraacetic acid disodium salt, its rate significantly enhances to 14.5 mmol g−1 h−1, superior to most reported organic photocatalysts to the best of the knowledge.