Nanoporous insulating oxide deionization device having asymmetric electrodes and method of use thereof

Abstract

A nanoporous insulating oxide deionization device, method of manufacture and method of use thereof for deionizing a water supply (such as a hard water supply), for desalinating a salt water supply, and for treating a bacteria-containing water supply. The device contains two composite electrodes each constructed from a conductive backing electrode and a composite oxide layer being an insulating oxide or a non-insulating oxide and an intermediate porous layer. The composite layer being substantially free of mixed oxidation states and nanoporous and having a median pore diameter of 0.5-500 nanometers and average surface area of 300-600 m/g. The composite layer made from a stable sol-gel suspension containing particles of the insulating oxide, the median primary particle diameter being 1-50 nanometers. The difference in zeta potential, at a pH in the range of 6-9, being sufficient to suitably remove alkaline and alkaline earth cations (such as Caand Na), various organic and other inorganic cations and organic and inorganic anions from water, preferably household hard water. One composite layer being constructed from a mixture of AlO, MgAlOand/or Mg-doped AlOparticles, and the other composite layer being constructed from SiOor TiO.