No abstract

The development of novel photocatalytic systems for energy-saving and efficient water purification and sterilization is extremely challenging but crucial for the prevention of chronic diseases caused by water pollution and bacteria. The self-aggregation of photosensitizers (PSs) driven by tight π−π stacking leads to a sharp decline in the ability to generate reactive oxygen species (ROS) and has become the main bottleneck for the application of PSs in photocatalytic water purification and sterilization. Herein, a series of porous anthracene-based metal− organic frameworks (MOFs) {[Zn(L) 2 (DEF) 2 ] n •2nDEF•nH 2 O (GXNU-1), [Co 2 (L) 4 (DEF) 2 ] n •4nDEF•8nH 2 O (GXNU-2), and [Ni(L) 2 (DEF) 2 ] n •nDEF•4nH 2 O (GXNU-3)} with excellent ROS generation ability were designed and synthesized.The energy level structures of GXNU-1−3 were determined by electrochemical experiments, which proved that all the frameworks have the ability to produce 1 O 2 . In addition, the photocurrent response and electrochemical impedance spectroscopy (EIS) proved that the formation of MOF structures can effectively enhance the charge separation ability and promote photogenerated holes and excitons under light-driven conditions, thereby further promoting the rapid generation of ROS. Their ability to catalyze the rapid purification and sterilization of high-concentration dye wastewater under low-power (60 mW•cm −2 ) light irradiation was then determined. The porous framework structure prevents the tight π−π stacking of anthracene-based PSs and increases the contact sites with oxygen. Moreover, the introduction of metal ions promotes the intersystem crossing of excitons through spin−orbit coupling. These advantages greatly enhance the ROS generation ability of GXNU-1−3 in aqueous solutions. Notably, GXNU-1−3 almost completely degraded highconcentration organic dyes, such as crystal violet (CV), methylene blue (MB), rhodamine B (RhB), and orange II (OII). In addition, GXNU-1 efficiently degraded mixed organic dyes of CV (30 mg•L −1 ) and MB (10 mg•L −1 ) within 30 min of light irradiation, thereby showing a surprising ability to purify multicomponent dye wastewater. The heterogeneous GXNU-1−3 can be rapidly separated from the aqueous solution by centrifugation and filtration to avoid secondary pollution. More notably, GXNU-1 can effectively inhibit the rapid proliferation of Gram-negative/positive bacteria under light irradiation conditions. Masks and experimental clothes soaked in a GXNU-1 aqueous solution for 15 s clearly resisted bacterial contamination after being exposed to 60 mW•cm −2 light irradiation for 4 min. These findings open new horizons for the construction of novel photocatalytic systems that are fast, efficient, and environmentally friendly.