TECHNOLOGY FOCUS - ELECTRONICS - Preferred Method: The photoactive electrode optionally comprises photoactive composition. The composition is formed as a film on the surface of a substrate. The composition is translucent; and comprises Fe2O3, and TiO2. The voltage is applied to the photoactive electrode by a power source, preferably battery; or by exposing the photoactive electrode to electromagnetic radiation. The electromagnetic radiation is provided by sunlight, or an artificial light source. The photoactive electrode is exposed to electromagnetic radiation through a mask. The photoanode catalytically produces oxygen from gaseous water or liquid water. The voltage is applied to the photoactive electrode for 1 minute to 24 hours. The photoactive composition is integrally connected with the catalytic material. The illumination is provided by sunlight or an artificial light source which is a lamp. The water is in liquid state or gaseous state. The method is conducted at approximately ambient temperatures or at temperatures greater than 30 degrees C. The impurity is gas (preferably carbon monoxide or carbon dioxide) which is dissolved in the electrolyte. The pH of the electrolyte or solution is less than or equal to neutral (preferably 8-6, 7-4, less than 8, 7-1, 7-2, 5-9 or greater than 8). The metal ionic species and the anionic species participate in a catalytic reaction involving a dynamic equilibrium in which at least a portion of the metal ionic species are cyclically oxidized and reduced, hence associating and disassociating, respectively, from the first electrode. The illuminating the photoelectrochemical cell with light produces fuel (preferably hydrogen, hydrocarbon or any fuel resulting from the reduction of carbon monoxide or carbon dioxide) at the second electrode. The photoactive composition and the catalytic material are integrally connected. Preferred Photoanode: The ratio of cobalt ions to anionic species comprising phosphorus is 5:1 to 1:5 (preferably 3:1 to 1:3, especially 2:1). The ratio of cobalt ions:anionic species comprising phosphorus:cationic species is 2:1:1. Preferred Cell: The photoelectrochemical cell additionally comprises a second electrode; a power source; and unit for connecting the first electrode and the second electrode. The electrolyte comprises water. The electrolyte comprises a solid; and is solid polymer electrolyte or non-permeable electrolyte. The cell produces hydrogen gas from water.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalytic material does not consist of metal oxide and/or metal hydroxide. The solution additionally comprises counter anions, where the counter anions were associated with the metal ionic species before forming the solution comprising the metal ionic species. The solution additionally comprises counter cations associated with the anionic species before forming the solution comprising the anionic species. The anionic species does not consist of hydroxide ion or oxide ions. The catalytic material is non-crystalline and forms a layer on the photoactive electrode. The catalytic material associated with the photoactive electrode optionally has uniform thickness. The catalytic material associated with the photoactive electrode has an average thickness of less than 10 (preferably less than 1) mu m, or less than 100 (preferably less than 10, especially less than 1) nm. The thickness of the catalytic material associated with the photoactive electrode is dependent on the length of time the voltage is applied to the photoactive electrode. The catalytic material formed comprises coalesced particles associated with the photoactive electrode. The anionic species comprises phosphorus. The metal ionic species comprises cobalt ions. The catalytic material is translucent. The metal ionic species with an oxidation state of (n+x) and the anionic species define a non-crystalline composition and have a Ksp value which is less, by a factor of at least 103, than the Ksp value of a composition comprising the metal ionic species with an oxidation state of (n) and the anionic species. The second electrode is photoactive electrode. The water contains at least one impurity. The impurity comprises a metal (preferably metal element, metal ion, compound comprising a metal atom or an ionic species comprising a metal ion, especially lithium, sodium, magnesium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, potassium, mercury, lead, or barium); an organic material, small organic molecule, bacteria, pharmaceutical compound, herbicide, pesticide, protein, an inorganic compound; or gas. The inorganic compound comprises boron, silicon, sulfur, nitrogen, cyanide, phosphorus or arsenic. The at least one impurity is present in an amount less than 1000 (preferably less than 100, especially less than 10, particularly less than 1) ppm; or less than 100 (preferably less than 10, especially less than 1) ppb. The metal ionic species comprise at least a first type and a second type of metal ionic species. The first type of metal ionic species comprises cobalt ions. The second type of metal ionic species comprises nickel ions or manganese ions. The anionic species does not consist essentially of hydroxide or oxide ions. The anionic species comprise at least a first type and a second type of anionic species. The first type of anionic species comprises oxides or hydroxides; and the second type of anionic species comprises phosphorus. The photosensitizing agent comprises a metal complex dye; an organic dye; metal; an organic component (preferably at least one of biquinoline, bipyridyl, phenanthroline, or thiocyanic acid); halide ion; porphyrin-based system. The porphyrin-based system is selected from 8 compounds as given in the specification, e.g. 4-((5Z,10Z,14Z,19Z)-10,15,20-tri-para-tolyl-porphyrin-5-yl)-benzoic acid, 4-((5Z,10Z,14Z,19Z)-10,15,20-tris-(2,6-dichloro-phenyl)-porphyrin-5-yl)-benzoic acid, 4-((5Z,10Z,14Z,19Z)-10,15,20-tris-pentafluorophenyl-porphyrin-5-yl)-benzoic acid, (1Z,4Z,9Z,15Z)-5-(4-fluoro-phenyl)-10,20-bis-pentafluorophenyl-15-para-tolyl-porphyrin; an anion; or dianion; and additionally comprises a metal. The photosensitizing agent is translucent. The photoactive electrode consists of the photoactive composition and the photosensitizing agent. The photoactive electrode does not consist of the photoactive composition and the photosensitizing agent. The photoactive composition is integrally connected with the photosensitizing agent. The photosensitizing agent is integrally connected with the catalytic material. The photosensitizing agent comprises quantum dots (preferably ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, PbS, Bi2S3, HgS, HgSe, HgTe, MgTe, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, AlAs, AlP, AlSb, or AlS). The anionic species comprising phosphorus is selected from HPO4-2, H2PO4-2, PO4-3, H3PO3, HPO3-2, H2PO3-2, PO3-3, or HPO4-4. A complex comprising the cobalt ions and the anionic species comprising phosphorus, has a Ksp constant of 10-3 to 10-20. The anionic species comprising phosphorus comprises a structure PO(OR1)(OR2)(R3) (preferably PO3Me-2). The catalytic material and the photoactive composition are in direct electrical communication; or integrally connected. The Ksp values differ by a factor of at least 105 (preferably at least 1010, especially at least 1015). The catalytic material further comprises a cationic species (preferably K+). The catalytic material formation is greater in areas that were exposed to greater levels of electromagnetic radiation than areas that received less electromagnetic radiation. The catalytic material comprises a first type of metal ionic species and a second type of metal ionic species; or first type of anionic species and second type of anionic species. The anionic species is selected from phosphate, forms of sulfate, forms of carbonate, forms of arsenate, forms of phosphite, forms of silicate, or forms of borate. The metal ionic species and the anionic species are in dynamic equilibrium with the water comprised in the electrolyte.R1-R3=(hetero)alkyl, (hetero)alkenyl, (hetero)alkynyl or (hetero)aryl (all optionally substituted, or optionally absent) or H. EXAMPLE - No suitable example given.