The photosensitive unit and conjugation play a significant role in photocatalytic performance of covalent organic frameworks (COFs). In this work, a series of COFs that introduced the phenyl phenanthridine as photosensitive unit with different planarity of linkages were synthesized and the common regulation between them for photocatalysis hydrogen evolution reaction (HER) was also studied. The results indicate that DHTB-PPD, with 2/3 planarity linkages (β-ketoenamine/imine is 2/3) and the phenyl phenanthridine as building blocks, shows the narrowest bandgap and the strongest charge separation efficiency.
View Article and Find Full Text PDFCovalent organic frameworks (COFs) for detecting biological macromolecules in water or biological environments are generally challenging. In this work, a composite material IEP-MnO is obtained by combining manganese dioxide (MnO) nanocrystals and a fluorescent COF (IEP), which is synthesized by using 2,4,6-tris(4-aminophenyl)--triazine and 2,5-dimethoxyterephthalaldehyde. By the addition of biothiols, such as glutathione, cysteine or homocysteine with different sizes, the fluorescence emission spectra of IEP-MnO changed ("turn-on" or "turn-off") different mechanisms.
View Article and Find Full Text PDFImproving the luminescence properties of covalent organic frameworks (COFs) has always been an important issue. Here, a series of COFs (([OMe] -TzDa (TzDa is composed only by monomerics Tz and Da, OMe represents the incorporation of monomeric Dm)) with different ratios of OMe and OH were designed and synthesized. The photochemical behavior of [OMe] -TzDa changed significantly due to the synergistic effect of aggregation induced emission (AIE), intramolecular charge transfer (ICT), and excited-state intramolecular proton transfer (ESIPT) effects.
View Article and Find Full Text PDFBackground: To investigate the efficacy of glucocorticoid and terbutaline in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD).
Methods: 248 patients with AECOPD were assigned into two groups, 124 patients in the control group were only given terbutaline treatment, while 124 patients in the experimental group were treated with glucocorticoid and terbutaline. The effect on lung function and blood gas indexes were compared between the two groups.