Nanoporous Cathodes for High-Energy Li–S Batteries from Gyroid Block Copolymer Templates

This study reports on a facile approach to the fabrication of nanoporous carbon cathodes for lithium sulfur batteries using gyroid carbon replicas based on use of polystyrene-poly-4-vinylpyridine (PS-P4VP) block copolymers as sacrificial templates. The free-standing gyroid carbon network with a highly ordered and interconnected porous structure has been fabricated by impregnating the carbon precursor solution into the gyroid block copolymer nanotemplates and subsequently carbonizing them. A wide range of analytical tools have been employed to characterize fabricated porous carbon material. Prepared nanostructures are envisioned to have a great potential in myriad areas such as energy storage/conversion devices owing to their fascinating morphology exhibiting high surface area and uniform porosity with interconnected three-dimensional networks. The resulting carbon nanoporous structures infused with elemental sulfur have been found to work as a promising electrode for lithium sulfur batteries demonstrating a high cycling stability over more than 200 cycles

ZIF‑8 Films Prepared by Femtosecond Pulsed-Laser Deposition

As metal–organic frameworks (MOFs) are coming of age, processing strategies and morphology engineering have gained considerable importance, given the need of thin film geometries for many applications. Using the femtosecond pulsed-laser deposition (femto-PLD) technique, we have fabricated films of the zeolitic imidazolate framework (ZIF) zinc 2-methylimidazolate (ZIF-8) for the first time, thus extending the available film fabrication techniques for MOFs to physical vapor deposition. While deposition of pristine ZIF-8 turned out to be unsuccessful, we demonstrate that hybrid ZIF-8 impregnated with polyethylene glycol 400 as a “vehicle” ablate under ultrahigh vacuum conditions to form films with approximate composition Zn­(C₃N₂H₂–CH₃)₂·¹/₆PEG-400. By washing the films with ethanol, the polyethylene glycol (PEG) additive can be removed, leading to pure ZIF-8 films on sapphire substrates. The target films and powders were comprehensively characterized by diffraction, spectroscopic and microscopic techniques as well as thermogravimetry and Ar physisorption measurements