Tris(triazolo)triazine‐based Covalent Organic Frameworks for Efficiently Photocatalytic Hydrogen Peroxide Production

Abstract

Two‐dimensional covalent organic frameworks (2D‐COFs) have recently emerged as fascinating scaffolds for solar‐to‐chemical energy conversion because of their customizable structures and functionalities. Herein, two tris(triazolo)triazine‐based COF materials (namely COF‐JLU51 and COF‐JLU52) featuring large surface area, high crystallinity, excellent stability and photoelectric properties were designed and constructed for the first time. Remarkably, COF‐JLU51 gave an outstanding H2O2 production rate of over 4200 µmol g−1 h−1 with excellent reusability in pure water and O2 under one standard sun light, that higher than its isomorphic COF‐JLU52 and most of the reported metal‐free materials, owing to its superior generation, separation and transport of photogenerated carriers. Experimental and theoretical researches prove that the photocatalytic process undergoes a combination of indirect 2e− O2 reduction reaction (ORR) and 4e− H2O oxidation reaction (WOR). Specifically, an ultrahigh yield of 7624.7 µmol g−1 h−1 with apparent quantum yield of 18.2% for COF‐JLU52 was achieved in a 1:1 ratio of benzyl alcohol and water system. This finding contributes novel, nitrogen‐rich and high‐quality tris(triazolo)triazine‐based COF materials, and also designate their bright future in photocatalytic solar transformations.