Search

Donor–acceptor two-dimensional covalent organic frameworks, PD-COF-23 and PD-COF-23-Ni, are constructed and applied for selective CO2 reduction with CO conversion rates of 20.9 μmol g−1 h−1 and 40.0 μmol g−1 h−1, respectively, in the absence of any additional photosensitizers and noble metal co-catalysts within an operation time of 25 h. The multilayer nanosheet structure, efficient charge separation and transport, and internal reductive quenching cycle of the NiTAPP fragments of PD-COF-23-Ni result in its higher photocatalytic efficiency than that of PD-COF-23. [ABSTRACT FROM AUTHOR]

Li–S secondary batteries use lithium metal as the anode. The safety hazard arising from the Li dendrite formation on the metal surface presents a formidable challenge that has hindered the technology from practical applications for many years. It has been confirmed that tiny and random lithium deposition takes place at the ion depletion layer on the surface of lithium metal. The time required to reach the ion depletion layer can be quantified using Sand's equation, in which the time is inversely proportional to the transference number of anions (t−). Therefore, restricting the mobility of anions enables avoidance of ion depletion. In this study, lithium 4-aminophenylsulfonyl(trifluoromethylsulfonyl)imide (LiATFSI) is grafted with poly(ethylene-alt-maleic anhydride) (PEMA, Mw = 100 000–500 000) using a cyclic imide to form a single ion conducting polymer electrolyte (PEMA-graft-LiATFSI). The polymer electrolyte membrane made of PEMA-graft-LiATFSI is capable of withstanding a high current density of ±50 mA cm−2 (normalized to the surface area of the lithium disk) in a lithium symmetric cell. More remarkably, the metallic luster of the lithium foil remains essentially intact even after a galvanostatic cycling test with a current density of ±10 mA cm−2 for over 1600 hours, suggesting that the membrane can effectively suppress Li dendrite formation and thus pave a way to use lithium metal directly as the anode material with sufficient energy capacity and good safety. The lithium–sulfur battery assembled with the membrane as the electrolyte as well as the separator delivered a stable capacity of 780.8 mA h g−1 after 1000 cycles at 1C. This work demonstrates the necessity and fundamental importance of single ion conducting electrolyte membranes for achieving safe and stable performance with high energy density lithium metal secondary batteries. [ABSTRACT FROM AUTHOR]

A mitochondria-permeable ruthenium(ii) complex has been designed as a responsive probe which may be used to sensitize the formation of singlet oxygen (ΦΔ= 0.93) and cause local damage in cellulowhen exposed to UV and near-infrared laser excitation. [ABSTRACT FROM AUTHOR]

Donor-acceptor two-dimensional covalent organic frameworks, PD-COF-23 and PD-COF-23-Ni, are constructed and applied for selective CO2 reduction with CO conversion rates of 20.9 μmol g-1 h-1 and 40.0 μmol g-1 h-1, respectively, in the absence of any additional photosensitizers and noble metal co-catalysts within an operation time of 25 h. The multilayer nanosheet structure, efficient charge separation and transport, and internal reductive quenching cycle of the NiTAPP fragments of PD-COF-23-Ni result in its higher photocatalytic efficiency than that of PD-COF-23.

Several acetylene bridged porphyrin-monophthalocyaninato ytterbium(III) hybrids, PZn-PcYb, PH(2)-PcYb and PPd-PcYb, have been prepared and characterized by (1)H and (31)P NMR, mass spectrometry, and UV-vis spectroscopy. Their photophysical and photochemical properties, especially the relative singlet oxygen ((1)O(2)) quantum yields and the two-photon absorption cross-section (σ(2)), were investigated. These three newly synthesized compounds exhibited very large σ(2) values and substantial (1)O(2) quantum yields upon photo-excitation, making them potential candidates as one- and two-photon photodynamic therapeutic agents.