Process for preparing a film of an oxide or a hydroxide of an element of groups IIB or IIIA of the periodic table, and the composite structures which include such a film

摘要

Process for depositing a film of a metal oxide or of a metal hydroxide on a substrate in an electrochemical cell, wherein (i) the metal hydroxide is of formula M(OH).sub.x A.sub.y, M representing at least one metallic species in an oxidation state i chosen from the elements in Groups II and III of the Periodic Table, A being an anion whose number of charges is n, 0 x≦i and x+ny=i,PP (ii) the electrochemical cell comprises (a) an electrode comprising the substrate, (b) a counterelectrode, (c) a reference electrode and (d) an electrolyte comprising a conducting solution comprising at least one salt of the metal M, the process comprising the steps of:PP dissolving oxygen in the electrolyte andPPimposing a cathode potential of less than the oxygen reduction potential and greater than the potential for deposition of the metal M in the electrolyte in question on the electrochemical cell.