Comparative Study on Photocatalytic Hydrogen Production Efficiency of Benzodifuran-Based Covalent Organic Frameworks: Impact of Carboxamide and Ethyl Carboxylate Side Chains

Visible light-driven hydrogen production from water using solar energy for chemical conversion represents a promising technological advancement. Among the competitive photocatalysts, covalent organic frameworks have garnered considerable attention. In this study, we introduce carboxamide side chains into benzodifuran-based covalent organic frameworks (BDF-COF-1) to propose an efficient strategy for photocatalytic hydrogen production. Additionally, a benzodifuran covalent organic framework featuring ethyl carboxylate side chains (BDF-COF-2) was synthesized to contrast with BDF-COF-1. Notably, BDF-COF-1 exhibited exceptional photocatalytic activity under visible light irradiation, achieving a hydrogen production rate of 57.48 mmol g–1 h–1, significantly surpassing that of BDF-COF-2 under identical conditions (4.40 mmol g–1 h–1).