FeCo nanoparticles (NPs) are promising soft magnetic nanomaterials for use in many applications; however, the present problem is how to prevent oxidation. The most powerful substance for protection of FeCo NPs is graphitic carbon (GC). Here, we present a novel and simple technique for the large-scale synthesis of GC-coated FeCo NPs with varied Fe/Co ratios based on the reductive thermal conversion of nanometric Prussian blue analogues (PBAs). The key point is that surfaces of PBA NP precursors are coordinately stabilized by an organic layer of oleylamine, which serves as a carbon source for the GC shells of FeCo NPs during the thermolysis of PBA NPs. We have also succeeded in the facile formation of a stable FeCo NP film with GC shells that displays magneto-optical properties. The technique could be adapted to other transition metals and would be used in versatile fields such as spintronics and biotechnology.
Aufgeladen: Die selektive elektrochemische Fluorierung von organischen Verbindungen gelingt mit dem Alkalimetallfluorid KF unter sehr milden Bedingungen (siehe Schema). Durch die Verwendung von Poly(ethylenglycol) konnten zwei lange bestehende Probleme überwunden werden: das der niedrigen Löslichkeit von Metallfluoriden in organischen Lösungsmitteln und das der niedrigen Nucleophilie von Fluoridionen in Fluorierungen.
In order to utilize ammomium halides (Et4NX, X = Cl, Br, I) as halogen mediator for electrocatalytic fluorination, cyclic voltammetry measurements of the halides were investigated. The catalytic current of the halides in the presence of a dithioacatal compound was observed and the macro-scale electrolysis of dithioacetals using the halogen mediator was also carried out in ionic liquid hydrogen fluoride (HF) salt to give the corresponding fluorinated products in excellent yields. The recycle use of the halogen mediator in the electrochemical fluorination was successfully demonstrated. More inexpensive halides such as potassium bromide and potassium iodide could be soluble in HF salt and worked well as halogen mediator for the electrocatalytic fluorination.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.