Robust inorganic membranes from detachable ultrathin tantalum oxide films.

We report a simple electrochemical method of making individual free-standing and uniform tantalum oxide membranes between 35 and 100 nm thick. These films can be separated, floated on water, and transferred onto various substrates such as Si wafers, glass slides, and TEM grids. Our membranes are mechanically, chemically, and thermally robust, have a high dielectric constant, and a high refractive index, making them potentially useful in sensors, optics, filtration, and catalysis.