FIELD: chemistry.
SUBSTANCE: water-electrolysing material used is melanin, melanin precursors or melanin derivatives, melanin versions, melanin analogues, natural or synthetic, pure or mixed with organic or inorganic compounds, metals, ions, medicines, using natural or artificial light which may or may not be coherent as the only or main source of energy in systems for producing hydrogen from water known as photoelectrochemical systems. These systems combine semiconductor material and a water electrolyser inside a monolithic structure for direct production of hydrogen from water using light (between 200 and 900 nm) as the main or only source of energy. At least two main criteria must be met: one is that the system or light-absorbing compound must generate sufficient energy to initiate, carry out and complete a photoelectrolysis reaction which is cost-effective and stable in an aqueous system, whereby these requirements are met by melanin, which therefore represents vital and critical progress in solving the main problem of photoelectrochemical structures.
EFFECT: procedure can be used to generate hydrogen, oxygen and high-energy electrons or conversely for synthesis of water through bonding of hydrogen and oxygen with generation of electricity; the procedure can be combined with other processes, giving rise to a multiplier effect; the procedure can also be used to reduce carbon dioxide, nitrates, sulphates etc.
13 cl
