NOVELTY - A colloidal solution of mixture of tungstic acid and organic material(s) is formed. The colloidal solution is ultrasonically stirred, and a layer of the colloidal solution is formed on a conductive substrate (37). The substrate is heated at a temperature of at least 350degreesC, to form an electrode with tungsten oxide film (14).    USE - For preparing electrode with tungsten oxide film, used in photoelectrochemical cell (both claimed) for photoelectrolysis of water into oxygen and hydrogen, and as photoanode in cell for photoelectrochemical degradation of organic waste. Also used for electrochromic display cell.    ADVANTAGE - The method provides electrode having favorable electrochromic and photoelectrochemical characteristics.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) electrode, which is obtained by the above method;    (2) photochemical system for cleavage of water into hydrogen and oxygen by light, which has electrically connected cells (1, 2), where cell (1) has the electrode, which is operated when in contact with aqueous solution of electrolyte in use to absorb wavelength range (I) of light to evolve hydrogen and protons are generated, and cell (2) has dye sensitized mesoporous photovoltaic film, which is operated on illumination in use by wavelength range (II) to drive the reduction of protons to hydrogen; and    (3) preparation of colloidal solution, where:    (i) an aqueous sodium tungstate solution (20) is passed through a cation exchange resin (24),    (ii) the obtained tungstic acid solution is mixed with organic material (28),    (iii) the resulting mixture is concentrated by evaporation under pressure, and    (iv) organic material (33) is added, and ultrasonically stirred, to obtain colloidal solution.    DESCRIPTION OF DRAWING(S) - The figure shows the process diagram explaining the electrode formation process.    tungsten oxide film (14)    aqueous sodium tungstate solution (20)    cation exchange resin (24)    organic materials (A, B) (28, 33)    conductive substrate (37)