Highly Crystalline Linear Poly-Imine Photocatalyst with Giant Internal Electric Field for Visible-Light-Driven Water Disinfection

Abstract

Conjugated linear polymers are promising metal-free photocatalysts for visible-light-driven photocatalytic water disinfection, but it was still bottlenecked by the insufficient photogenerated charge separation and transport (CST) process. Herein, we developed a new strategy for tuning the crystallinity of conjugated linear polymer via different solvent (poor/good solvent) systems to further regulate the CST efficiency. We obtained a highly crystalline imine-linked conjugated polymer photocatalyst (ODA-BPAH) with a giant Internal electric field (IEF), leading to excellent broad-spectrum water disinfection efficiency up to 99.99999% in 1h, which is among the reported highest of state-of-the-art photocatalysts. The superior photocatalytic activity could be ascribed to the strong IEF in ODA-BPAH boosting photogenerated CST as well as reactive oxygen species generation, while the low crystalline ODA-BPAH exhibits much weaker IEF and photocatalytic performance. This work highlights the impact of polymer crystallinity on the internal electric field and proves that linear poly-imine could be a new type of promising metal-free photocatalyst

Keywords: Polymeric photocatalysts, Water disinfection, Imine-linked conjugated polymer, High crystallinity, Internal electric field