The zeolitic imidazolate framework-8 (ZIF-8), as a kind of MOF, is widely used in sensors, gas storage/separation, drug delivery, and catalysis due to its adjustable porous structure, high surface area, and excellent chemistry tunability. ZIF-8 is constructed by Zn²⁺ and 2-methylimidazole and synthesized in the methanol solution. In this paper, we explored the influence of the reused methanol solution for the structure and properties of the synthesized ZIF-8. The as-synthesized ZIF-8 was characterized by an X-ray diffraction instrument (XRD), a scanning electron microscope (SEM), a specific surface area analyzer (BET), and Fourier transform infrared spectroscopy (FT-IR). The results show that the reused methanol solution does not change the phase, porous structure, and BET surface area of ZIF-8. However, the particle size of ZIF-8 increases from 50 nm to 5 um and the productive rate decreases to 7.4% when the methanol solution is reused four times. This work provides new insight into the reuse of dissolvents for the synthesis of MOFs.

Metal–organic frameworks (MOFs) have been widely used in various fields, including gas storage, separation, sensors, and catalysis, owing to their excellent performance. In this study, a zinc-based MOF [MIL-125(Zn)] was successfully synthesized using the solvothermal method, and Ag-doped ZnO (Ag/ZnO) was prepared by pyrolyzing Ag/MIL-125(Zn). The fabricated Ag/ZnO was used as a photocatalyst for rhodamine (RhB) degradation. Results showed that the MIL-125(Zn) derived from Ag/ZnO exhibits superior photocatalytic activity. It can degrade 99.4% of RhB under 20-min ultraviolet (UV) light irradiation, higher than those achieved using ZnO (73.2%) and MIL-125(ZnO) (19.6%). Furthermore, Ag/ZnO shows excellent stability. After four photocatalytic degradation cycles, the photocatalytic activity of Ag/ZnO reduces by only 3.6%. The excellent photocatalytic performance of Ag/ZnO may be attributed to the synergistic effect of Ag nanoparticles and ZnO. The possible photocatalytic mechanism of RhB degradation on the Ag/ZnO photocatalyst under UV light irradiation was proposed.

Causing more and more deaths, stroke has been a leading cause of death worldwide. However, success in clinical stroke trials has remained elusive. N-oleoylethanolamine (OEA) was an endogenous highly hydrophobic molecule with outstanding neuroprotective effect. In this article, hydrogen bonds were successfully formed between OEA and soybean phosphatidylcholine (SPC). The synthetic OEA-SPC complex and DSPE-PEG were self-assembled into liposomes (OEA NPs), with OEA-SPC loaded in the core and PEG formed a hydrophilic shell. Hence, highly hydrophobic OEA was loaded into liposomes as amorphous state with a drug loading of 8.21 ± 0.18 wt%. With fairly uniform size and well-distributed character, the OEA NPs were systemically assessed as an intravenous formulation for stroke therapy. The results indicated that the administration of OEA NPs could significantly improve the survival rate and the Garcia score of the MCAO rats compared with free OEA. The TTC-stained brain slices declared that the cerebral infarct volume and the edema degree induced by MCAO could be decreased to an extremely low level via the administration of OEA NPs. The Morris water maze (MWM) test suggested that the spatial learning and memory of the MCAO rats could also be ameliorated by OEA NPs. The immunofluorescence assay stated that the apoptosis of the neurons and the inflammation within the brain were greatly inhibited. The results suggest that the OEA NPs have a great chance to develop OEA as a potential anti-stroke formulation for clinic application.