Embedding Au nanoclusters into the pores of carboxylated COF for the efficient photocatalytic production of hydrogen peroxide

Abstract

Au nanoclusters (Au NCs) have attracted extensive attention as visible light photosensitizers for photo-redox catalysis on various supports. However, retaining the photostability of Au NCs at the support interface under prolonged illumination is still a challenge. Herein, TCOF was synthesized as a precursor, and COF–COOH with carboxy-quinoline in the pores was synthesized by post-modifying TCOF via the Doebner–Miller reaction. Meanwhile, the –COOH not only accelerated the separation and migration of photogenerated carriers, but also served as growth sites for the Au NCs, and the O–Au bond improved the stability of Au NCs under long-term illumination. More importantly, the photogenerated electrons of COF–COOH can rapidly migrate to the hot holes of Au NCs via COF–O–Au bridge bonds, which significantly improves the separation efficiency and utilization of photogenerated carriers, leading to the ultrahigh photocatalytic production of H₂O₂ (18 933.58 μmol g⁻¹ h⁻¹). This work will provide a new strategy for the functionalization of COFs and the construction of composite photocatalysts.