Copper-Organic Frameworks with Open Metal Sites and Amine Groups for Photocatalytic H۲ Evolution

Photocatalytic H۲ evolution has recently attracted much attention due to the reduction of non-renewable energy sources and the increasing demand for renewable sustainable energies.[۱] Meanwhile, metal-organic frameworks (MOFs) are emerging potential photocatalysts due to their structural adaptability, porous configuration, several active sites, and wide range of performance.[۲] Nevertheless, there are still limitations in the MOFs photocatalytic H۲ evolution reaction with the higher charge recombination rates.[۳] Herein, a copper-organic framework with dual functionalized linkers {[Cu۲(L)(H۲O)۲]·(۵DMF)(۴H۲O)}n (fluorinated MOF(Cu)-NH۲; H۴L = ۳,۵-bis(۲,۴-dicarboxylic acid)-۴-(trifluoromethyl)aniline) and with a rare ۲-nodal ۴,۱۲-connected shp topology has been synthesized by ligand-functionalization strategy and evaluated for the photocatalytic production of H۲ to overcome this issue. According to the photocatalytic H۲ evolution results, fluorinated MOF(Cu)-NH۲ showed a hydrogen evolution rate of ۶۳.۶۴ mmol.h−۱.g−۱ exposed to light irradiation, indicating values ۱۲ times that of the pure ligand when co-catalyst Pt and photosensitizer Rhodamine B (RhB) were present. Besides, this MOF showed maximum water absorption of ۲۰۵ cm۳.g−۱. When dual-functionalized linkers are introduced to the structure of this MOF, its visible-light absorption increases considerably, which can be associated with nearly narrower energy band gaps (۲.۱۸ eV).

کلیدواژه ها:

Metal–organic framework ، Water-stable ، Hydrogen evolution ، Dual functionalized linkers ، Photocatalyst