Suppressing the Excitonic Effect in Covalent Organic Frameworks for Metal-Free Hydrogen Generation.

ABSTRACT: Photocatalytic hydrogen generation is a promising solution for renewable energy production and plays a role in achieving carbon neutrality. Covalent organic frameworks (COFs) with highly designable backbones and inherent pores have emerged as novel photocatalysts, yet the strong excitonic effect in COFs can impede the promotion of energy conversion efficiency. Here, we propose a facile approach to suppress the excitonic effect in COFs, which is by narrowing the band gap and increasing the dielectric screening via a rational backbone design and chemical modifications. Based on the GW-BSE method, we uncover a linear relationship between the electronic dielectric constant and the inverse square of the optical band gap of COFs of the Lieb lattice. We further demonstrate that both reduced excit

SUBMITTER: Yu H 

PROVIDER: S-EPMC9400042 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature