Red light-active porphyrin-based Zr-MOF nanorods enable highly selective aerobic oxidation of sulfides and amines

Abstract

The strategic utilization of red-light-responsive photocatalysts presents a unique opportunity to perform organic reactions under mild conditions, thereby minimizing side reactions and broadening the scope of viable substrates. Herein, red light-active porphyrin-based Zr-MOF nanorods (NU-902-NR) were synthesized by a microwave method. The as-prepared NU-902-NR exhibits high surface areas, a hybrid micro/mesoporous structure, excellent stability and dispersity in water, and a wide absorption band in the visible light region, especially in the red light range, making it an excellent candidate for photocatalysis. NU-902-NR demonstrates excellent catalytic activities toward the selective aerobic oxidation of sulfides and amines under red light irradiation at room temperature. Detailed mechanism studies revealed that NU-902-NR is capable of activating O₂ to generate ¹O₂ and O₂˙⁻ under red light irradiation, thus oxidizing sulfides and benzylamines to sulfoxides and imines, respectively. Importantly, a higher selectivity of the imine product was achieved when the reaction was performed under red light irradiation rather than under blue light irradiation, indicating the advantages of low-energy red light in minimizing side reactions. The simplicity and rapid synthetic approach together with the versatile photochromic moieties hold great promise for synthesizing water-stable and red-light responsive porphyrinic Zr-MOF nanomaterials. This work also offers new potential for the selective aerobic photooxidation of sulfides and amines under green and mild conditions.