The present disclosure discloses an oxygen separation membrane with high permeability coated with electroactive materials on both sides thereof in which electronic conductive materials and ionic conductive materials are mixed in an optimal ratio whereby the oxygen separation membrane according to the present disclosure has high oxygen permeability and a good thermal stability. Further the present membrane can be advantageously prepared using a simple process such as Tape casting and using a simple sintering process.

Methods and systems directed to the separation of a heavy hydrogen isotope, e.g., tritium, from an aqueous stream are described. The methods and systems incorporate a separation media that includes a proton conducting ceramic that at low temperatures preferentially adsorbs heavy hydrogen isotopes and at high temperature preferentially adsorbs lighter heavy hydrogen isotopes. The methods can be temperature controlled to sequentially purify a contaminated stream and regenerate the separation media. The separation media can be free of traditional hydrogen isotope exchange catalyst materials.

High-quality membranes of complex oxide and complex nitrides are provided. Also provided are method of making the membranes by releasing films of the complex oxides and nitrides from an epitaxial heterostructure using metal islands on the surface of the films as strain-absorbing supports. The methods facilitate the release of flat, large-area membranes characterized by the absence of, or a very low density of, cracks and/or wrinkles. The released membranes are free of the surface organic residues that are present on membranes released with the aid of a polymer support.